repo stringclasses 1k
values | file_url stringlengths 96 373 | file_path stringlengths 11 294 | content stringlengths 0 32.8k | language stringclasses 1
value | license stringclasses 6
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values | retrieved_at stringdate 2026-01-04 14:45:56 2026-01-04 18:30:23 | truncated bool 2
classes |
|---|---|---|---|---|---|---|---|---|
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/ElectricComponent.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/ElectricComponent.java | package modern.circuit;
import modern.circuit.type.ElectricCircuit;
import modern.circuit.panel.ElectricBreaker;
import modern.circuit.capacitor.Capacitor;
import modern.circuit.resistor.Resistor;
import modern.circuit.transistor.Transistor;
public sealed interface ElectricComponent
permits ElectricCircuit, ElectricBreaker, Capacitor, Resistor, Transistor {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/type/ElectricCircuit.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/type/ElectricCircuit.java | package modern.circuit.type;
import modern.circuit.ElectricComponent;
public sealed abstract class ElectricCircuit implements ElectricComponent
permits ParallelCircuit, SeriesCircuit, ShortCircuit {
public abstract void on();
public abstract void off();
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/type/SeriesCircuit.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/type/SeriesCircuit.java | package modern.circuit.type;
import modern.circuit.ElectricComponent;
public final class SeriesCircuit extends ElectricCircuit {
public SeriesCircuit(ElectricComponent... comp) {}
@Override
public void off() {}
@Override
public void on() {}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/type/ShortCircuit.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/type/ShortCircuit.java | package modern.circuit.type;
import modern.circuit.ElectricComponent;
public final class ShortCircuit extends ElectricCircuit {
public ShortCircuit(ElectricComponent... comp) {}
@Override
public void on() {}
@Override
public void off() {}
} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/type/ParallelCircuit.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/type/ParallelCircuit.java | package modern.circuit.type;
import modern.circuit.ElectricComponent;
public final class ParallelCircuit extends ElectricCircuit {
public ParallelCircuit(ElectricComponent... comp) {}
@Override
public void off() {}
@Override
public void on() {}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/panel/ElectricPanel.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/panel/ElectricPanel.java | package modern.circuit.panel;
import modern.circuit.type.ElectricCircuit;
import modern.circuit.capacitor.CeramicCapacitor;
import modern.circuit.capacitor.ElectrolyticCapacitor;
import modern.circuit.resistor.CarbonResistor;
import modern.circuit.resistor.MetalFilmResistor;
import modern.circuit.resistor.MetalOxideResistor;
import modern.circuit.resistor.MetalResistor;
import modern.circuit.transistor.BipolarTransistor;
import modern.circuit.transistor.FieldEffectTransistor;
import modern.circuit.type.ParallelCircuit;
import modern.circuit.type.SeriesCircuit;
import modern.circuit.type.ShortCircuit;
public final class ElectricPanel implements ElectricBreaker {
private final ElectricCircuit centralCircuit;
private final ElectricCircuit peripheralCircuit;
private final ElectricCircuit auxiliaryCircuit;
public ElectricPanel() {
peripheralCircuit = new SeriesCircuit(
new ElectrolyticCapacitor(), new ElectrolyticCapacitor(),
new MetalFilmResistor(), new CarbonResistor()
);
auxiliaryCircuit = new ShortCircuit(
new CeramicCapacitor(), new ElectrolyticCapacitor(), new MetalResistor(),
new FieldEffectTransistor(), new FieldEffectTransistor()
);
centralCircuit = new ParallelCircuit(peripheralCircuit, auxiliaryCircuit,
new CeramicCapacitor(), new BipolarTransistor(), new MetalOxideResistor()
);
}
@Override
public void switchOn() {
auxiliaryCircuit.off();
peripheralCircuit.on();
centralCircuit.on();
}
@Override
public void switchOff() {
auxiliaryCircuit.on();
peripheralCircuit.off();
centralCircuit.off();
}
} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/panel/ElectricBreaker.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/panel/ElectricBreaker.java | package modern.circuit.panel;
import modern.circuit.ElectricComponent;
public sealed interface ElectricBreaker extends ElectricComponent
permits ElectricPanel {
void switchOn();
void switchOff();
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/capacitor/CeramicCapacitor.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/capacitor/CeramicCapacitor.java | package modern.circuit.capacitor;
public final class CeramicCapacitor extends Capacitor {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/capacitor/ElectrolyticCapacitor.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/capacitor/ElectrolyticCapacitor.java | package modern.circuit.capacitor;
public final class ElectrolyticCapacitor extends Capacitor {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/capacitor/Capacitor.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/capacitor/Capacitor.java | package modern.circuit.capacitor;
import modern.circuit.ElectricComponent;
public sealed abstract class Capacitor implements ElectricComponent
permits CeramicCapacitor, ElectrolyticCapacitor {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/resistor/CarbonResistor.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/resistor/CarbonResistor.java | package modern.circuit.resistor;
public final class CarbonResistor extends Resistor {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/resistor/MetalOxideResistor.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/resistor/MetalOxideResistor.java | package modern.circuit.resistor;
public final class MetalOxideResistor extends MetalResistor {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/resistor/MetalResistor.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/resistor/MetalResistor.java | package modern.circuit.resistor;
public sealed class MetalResistor extends Resistor
permits MetalFilmResistor, MetalOxideResistor {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/resistor/MetalFilmResistor.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/resistor/MetalFilmResistor.java | package modern.circuit.resistor;
public final class MetalFilmResistor extends MetalResistor {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/resistor/Resistor.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/resistor/Resistor.java | package modern.circuit.resistor;
import modern.circuit.ElectricComponent;
public sealed abstract class Resistor implements ElectricComponent
permits MetalResistor, CarbonResistor {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/transistor/BipolarTransistor.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/transistor/BipolarTransistor.java | package modern.circuit.transistor;
public final class BipolarTransistor extends Transistor {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/transistor/Transistor.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/transistor/Transistor.java | package modern.circuit.transistor;
import modern.circuit.ElectricComponent;
public sealed abstract class Transistor implements ElectricComponent
permits FieldEffectTransistor, BipolarTransistor {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/transistor/FieldEffectTransistor.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/circuit/transistor/FieldEffectTransistor.java | package modern.circuit.transistor;
public final class FieldEffectTransistor extends Transistor {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/challenge/client/Main.java | Chapter08/P176_SealedElectricPanelHierarchy/src/main/java/modern/challenge/client/Main.java | package modern.challenge.client;
import modern.circuit.panel.ElectricPanel;
public class Main {
public static void main(String[] args) {
ElectricPanel panel = new ElectricPanel();
panel.switchOn();
System.out.println("Power on ...");
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P179_SealedClassesSwitchBinTree/src/main/java/modern/challenge/Main.java | Chapter08/P179_SealedClassesSwitchBinTree/src/main/java/modern/challenge/Main.java | package modern.challenge;
import modern.challenge.Main.BinaryTree.Leaf;
import modern.challenge.Main.BinaryTree.Node;
public class Main {
sealed interface BinaryTree {
record Leaf() implements BinaryTree {}
record Node(int value, BinaryTree left, BinaryTree right) implements BinaryTree {}
}
static int sumNode(BinaryTree t) {
return switch (t) {
case Leaf nl -> 0;
case Node nv -> nv.value() + sumNode(nv.left()) + sumNode(nv.right());
};
}
public static void main(String[] args) {
BinaryTree leaf = new Leaf();
BinaryTree s1 = new Node(5, leaf, leaf);
BinaryTree s2 = new Node(10, leaf, leaf);
BinaryTree s = new Node(4, s1, s2);
int sum = sumNode(s);
System.out.println("Sum: " + sum);
}
} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/module-info.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/module-info.java | module P175_SealedHierarchySeparatePackages {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/modern/challenge/Main.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/modern/challenge/Main.java | package modern.challenge;
public class Main {
public static void main(String[] args) {}
} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/rafinery/fuel/type/LiquidFuel.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/rafinery/fuel/type/LiquidFuel.java | package com.rafinery.fuel.type;
import com.refinery.fuel.Fuel;
import com.refinery.liquidfuel.Petroleum;
public sealed interface LiquidFuel extends Fuel permits Petroleum {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/rafinery/fuel/type/SolidFuel.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/rafinery/fuel/type/SolidFuel.java | package com.rafinery.fuel.type;
import com.refinery.fuel.Fuel;
import com.refinery.solidfuel.Charcoal;
import com.refinery.solidfuel.Coke;
public sealed interface SolidFuel extends Fuel permits Coke, Charcoal {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/rafinery/fuel/type/GaseousFuel.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/rafinery/fuel/type/GaseousFuel.java | package com.rafinery.fuel.type;
import com.refinery.fuel.Fuel;
import com.refinery.gaseousfuel.NaturalGas;
import com.refinery.gaseousfuel.Propane;
public sealed interface GaseousFuel extends Fuel permits NaturalGas, Propane {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/liquidfuel/Gasoline.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/liquidfuel/Gasoline.java | package com.refinery.liquidfuel;
public final class Gasoline extends Petroleum {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/liquidfuel/Diesel.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/liquidfuel/Diesel.java | package com.refinery.liquidfuel;
public final class Diesel extends Petroleum {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/liquidfuel/Petroleum.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/liquidfuel/Petroleum.java | package com.refinery.liquidfuel;
import com.rafinery.fuel.type.LiquidFuel;
public sealed class Petroleum implements LiquidFuel permits Diesel, Gasoline, Ethanol {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/liquidfuel/Ethanol.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/liquidfuel/Ethanol.java | package com.refinery.liquidfuel;
public final class Ethanol extends Petroleum {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/gaseousfuel/Dichloromethane.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/gaseousfuel/Dichloromethane.java | package com.refinery.gaseousfuel;
public sealed class Dichloromethane extends Methane permits Trichloromethane {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/gaseousfuel/Propane.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/gaseousfuel/Propane.java | package com.refinery.gaseousfuel;
import com.rafinery.fuel.type.GaseousFuel;
public final class Propane implements GaseousFuel {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/gaseousfuel/Chloromethane.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/gaseousfuel/Chloromethane.java | package com.refinery.gaseousfuel;
public final class Chloromethane extends Methane {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/gaseousfuel/Methane.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/gaseousfuel/Methane.java | package com.refinery.gaseousfuel;
public sealed class Methane implements NaturalGas permits Chloromethane, Dichloromethane {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/gaseousfuel/Trichloromethane.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/gaseousfuel/Trichloromethane.java | package com.refinery.gaseousfuel;
public final class Trichloromethane extends Dichloromethane {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/gaseousfuel/Hydrogen.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/gaseousfuel/Hydrogen.java | package com.refinery.gaseousfuel;
public final class Hydrogen implements NaturalGas {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/gaseousfuel/NaturalGas.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/gaseousfuel/NaturalGas.java | package com.refinery.gaseousfuel;
import com.rafinery.fuel.type.GaseousFuel;
public sealed interface NaturalGas extends GaseousFuel permits Hydrogen, Methane {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/solidfuel/Coke.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/solidfuel/Coke.java | package com.refinery.solidfuel;
import com.rafinery.fuel.type.SolidFuel;
public final class Coke implements SolidFuel {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/solidfuel/Charcoal.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/solidfuel/Charcoal.java | package com.refinery.solidfuel;
import com.rafinery.fuel.type.SolidFuel;
public final class Charcoal implements SolidFuel {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/fuel/Fuel.java | Chapter08/P175_SealedHierarchySeparatePackages/src/main/java/com/refinery/fuel/Fuel.java | package com.refinery.fuel;
import com.rafinery.fuel.type.GaseousFuel;
import com.rafinery.fuel.type.LiquidFuel;
import com.rafinery.fuel.type.SolidFuel;
public sealed interface Fuel permits SolidFuel, LiquidFuel, GaseousFuel {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P184_HiddenClasses/src/main/java/modern/challenge/InternalMath.java | Chapter08/P184_HiddenClasses/src/main/java/modern/challenge/InternalMath.java | package modern.challenge;
import java.util.stream.IntStream;
public class InternalMath implements Math {
public long sum(int[] nr) {
return IntStream.of(nr).sum();
}
} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P184_HiddenClasses/src/main/java/modern/challenge/Main.java | Chapter08/P184_HiddenClasses/src/main/java/modern/challenge/Main.java | package modern.challenge;
import java.io.IOException;
import java.io.InputStream;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodHandles.Lookup.ClassOption;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
public class Main {
public static void main(String[] args)
throws IOException, IllegalAccessException, NoSuchMethodException,
InstantiationException, IllegalArgumentException, InvocationTargetException {
/* creating a hidden class */
MethodHandles.Lookup lookup = MethodHandles.lookup();
Class<?> clazz = InternalMath.class;
String clazzPath = clazz.getName().replace('.', '/') + ".class";
InputStream stream = clazz.getClassLoader().getResourceAsStream(clazzPath);
byte[] clazzBytes = stream.readAllBytes();
Class<?> hiddenClass = lookup.defineHiddenClass(clazzBytes,
true, ClassOption.NESTMATE).lookupClass();
/* using a hidden class */
// Object obj = hiddenClass.getConstructor().newInstance(); // without the Math interface
Math obj = (Math) hiddenClass.getConstructor().newInstance(); // with the Math interface
Method method = obj.getClass()
.getDeclaredMethod("sum", int[].class);
System.out.println(method.invoke(obj, new int[]{4, 1, 6, 7}));
}
} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P184_HiddenClasses/src/main/java/modern/challenge/Math.java | Chapter08/P184_HiddenClasses/src/main/java/modern/challenge/Math.java | package modern.challenge;
public interface Math {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P178_SealedClassesCastConvInstanceof3/src/main/java/modern/challenge/Triangle.java | Chapter08/P178_SealedClassesCastConvInstanceof3/src/main/java/modern/challenge/Triangle.java | package modern.challenge;
public class Triangle {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P178_SealedClassesCastConvInstanceof3/src/main/java/modern/challenge/Quadrilateral.java | Chapter08/P178_SealedClassesCastConvInstanceof3/src/main/java/modern/challenge/Quadrilateral.java | package modern.challenge;
public sealed interface Quadrilateral permits Rectangle {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P178_SealedClassesCastConvInstanceof3/src/main/java/modern/challenge/Rectangle.java | Chapter08/P178_SealedClassesCastConvInstanceof3/src/main/java/modern/challenge/Rectangle.java | package modern.challenge;
// public final class Rectangle extends Triangle implements Quadrilateral {}
public final class Rectangle implements Quadrilateral {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P178_SealedClassesCastConvInstanceof3/src/main/java/modern/challenge/Main.java | Chapter08/P178_SealedClassesCastConvInstanceof3/src/main/java/modern/challenge/Main.java | package modern.challenge;
public class Main {
public static void drawTriangle(Triangle t) {
// if (t instanceof Quadrilateral) { // the compiler is aware that 't' cannot be a Quadrilateral
// System.out.println("This is not a triangle");
//} else {
System.out.println("Drawing a triangle");
//}
}
public static void main(String[] args) {}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P180_SealedClassesAndVisitorPattern2/src/main/java/modern/challenge/ElectricCircuit.java | Chapter08/P180_SealedClassesAndVisitorPattern2/src/main/java/modern/challenge/ElectricCircuit.java | package modern.challenge;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public final class ElectricCircuit implements ElectricComponent {
private final int id;
private final List<ElectricComponent> comps = new ArrayList<>();
public ElectricCircuit(int id) {
this.id = id;
}
public int getId() {
return id;
}
public List<ElectricComponent> getComps() {
return comps;
}
public void add(ElectricComponent... comp) {
comps.addAll(Arrays.asList(comp));
}
} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P180_SealedClassesAndVisitorPattern2/src/main/java/modern/challenge/Transistor.java | Chapter08/P180_SealedClassesAndVisitorPattern2/src/main/java/modern/challenge/Transistor.java | package modern.challenge;
public final class Transistor implements ElectricComponent {
private final float length;
private final float width;
private final float threshholdVoltage;
public Transistor(float length, float width, float threshholdVoltage) {
this.length = length;
this.width = width;
this.threshholdVoltage = threshholdVoltage;
}
public float getLength() {
return length;
}
public float getWidth() {
return width;
}
public float getThreshholdVoltage() {
return threshholdVoltage;
}
} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P180_SealedClassesAndVisitorPattern2/src/main/java/modern/challenge/ElectricComponent.java | Chapter08/P180_SealedClassesAndVisitorPattern2/src/main/java/modern/challenge/ElectricComponent.java | package modern.challenge;
public sealed interface ElectricComponent
permits Capacitor, Transistor, Resistor, ElectricCircuit {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P180_SealedClassesAndVisitorPattern2/src/main/java/modern/challenge/Main.java | Chapter08/P180_SealedClassesAndVisitorPattern2/src/main/java/modern/challenge/Main.java | package modern.challenge;
public class Main {
public static void main(String[] args) {
Capacitor c1 = new Capacitor(28, 20, 40);
Capacitor c2 = new Capacitor(26, 22, 30);
Resistor r1 = new Resistor(100, 2.5f, 5, 50, 0.25f);
Transistor t1 = new Transistor(0.09f, 0.27f, 0.1f);
Resistor r2 = new Resistor(98, 2.4f, 4, 40, 0.22f);
Transistor t2 = new Transistor(0.07f, 0.25f, 0.2f);
Capacitor c3 = new Capacitor(25, 21, 29);
Resistor r3 = new Resistor(97, 2.3f, 5, 45, 0.20f);
ElectricCircuit ec1 = new ElectricCircuit(1);
ElectricCircuit ec2 = new ElectricCircuit(2);
ElectricCircuit ec3 = new ElectricCircuit(3);
ElectricCircuit ec4 = new ElectricCircuit(4);
ec1.add(c1, c2, r1, t1);
ec2.add(r2, t2, ec1);
ec3.add(c3, r3, ec2);
ec4.add(ec3, c1, c2);
export(ec4);
}
private static void export(ElectricComponent circuit) {
StringBuilder sb = new StringBuilder();
sb.append("<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
export(sb, circuit);
System.out.println(sb.toString());
}
private static String export(StringBuilder sb, ElectricComponent... comps) {
for (ElectricComponent comp : comps) {
switch (comp) {
case Capacitor c ->
sb.append("""
<capacitor>
<maxImpedance>%s</maxImpedance>
<dielectricResistance>%s</dielectricResistance>
<coreTemperature>%s</coreTemperature>
</capacitor>
""".formatted(c.getMaxImpedance(), c.getDielectricResistance(), c.getCoreTemperature())).toString();
case Transistor t ->
sb.append("""
<transistor>
<length>%s</length>
<width>%s</width>
<threshholdVoltage>%s</threshholdVoltage>
</transistor>
""".formatted(t.getLength(), t.getWidth(), t.getThreshholdVoltage())).toString();
case Resistor r ->
sb.append("""
<resistor>
<resistance>%s</resistance>
<clazz>%s</clazz>
<voltage>%s</voltage>
<current>%s</current>
<power>%s</power>
</resistor>
""".formatted(r.getResistance(), r.getClazz(),
r.getVoltage(), r.getCurrent(), r.getPower())).toString();
case ElectricCircuit ec ->
sb.append("""
<electric_circuit_%s>
%s\
</electric_circuit_%s>
""".formatted(ec.getId(),
export(new StringBuilder(), ec.getComps().toArray(ElectricComponent[]::new)),
ec.getId()).indent(3)).toString();
}
}
return sb.toString();
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P180_SealedClassesAndVisitorPattern2/src/main/java/modern/challenge/Capacitor.java | Chapter08/P180_SealedClassesAndVisitorPattern2/src/main/java/modern/challenge/Capacitor.java | package modern.challenge;
public final class Capacitor implements ElectricComponent {
private final int maxImpedance;
private final int dielectricResistance;
private final int coreTemperature;
public Capacitor(int maxImpedance, int dielectricResistance, int coreTemperature) {
this.maxImpedance = maxImpedance;
this.dielectricResistance = dielectricResistance;
this.coreTemperature = coreTemperature;
}
public int getMaxImpedance() {
return maxImpedance;
}
public int getDielectricResistance() {
return dielectricResistance;
}
public int getCoreTemperature() {
return coreTemperature;
}
} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter08/P180_SealedClassesAndVisitorPattern2/src/main/java/modern/challenge/Resistor.java | Chapter08/P180_SealedClassesAndVisitorPattern2/src/main/java/modern/challenge/Resistor.java | package modern.challenge;
public final class Resistor implements ElectricComponent {
private final int resistance;
private final float clazz;
private final int voltage;
private final int current;
private final float power;
public Resistor(int resistance, float clazz, int voltage, int current, float power) {
this.resistance = resistance;
this.clazz = clazz;
this.voltage = voltage;
this.current = current;
this.power = power;
}
public int getResistance() {
return resistance;
}
public float getClazz() {
return clazz;
}
public int getVoltage() {
return voltage;
}
public int getCurrent() {
return current;
}
public float getPower() {
return power;
}
} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P105_DtoRecordConstructor/src/main/java/com/bookstore/MainApplication.java | Chapter04/P105_DtoRecordConstructor/src/main/java/com/bookstore/MainApplication.java | package com.bookstore;
import com.bookstore.dto.AuthorDto;
import java.util.List;
import com.bookstore.service.BookstoreService;
import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
@SpringBootApplication
public class MainApplication {
private final BookstoreService bookstoreService;
public MainApplication(BookstoreService bookstoreService) {
this.bookstoreService = bookstoreService;
}
public static void main(String[] args) {
SpringApplication.run(MainApplication.class, args);
}
@Bean
public ApplicationRunner init() {
return args -> {
List<AuthorDto> authors = bookstoreService.fetchByGenre();
System.out.println("Number of authors:" + authors.size());
for (AuthorDto author : authors) {
System.out.println("Author name: " + author.name()
+ " | Age: " + author.age());
}
};
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P105_DtoRecordConstructor/src/main/java/com/bookstore/dto/AuthorDto.java | Chapter04/P105_DtoRecordConstructor/src/main/java/com/bookstore/dto/AuthorDto.java | package com.bookstore.dto;
public record AuthorDto(String name, int age) {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P105_DtoRecordConstructor/src/main/java/com/bookstore/service/BookstoreService.java | Chapter04/P105_DtoRecordConstructor/src/main/java/com/bookstore/service/BookstoreService.java | package com.bookstore.service;
import com.bookstore.dto.AuthorDto;
import java.util.List;
import com.bookstore.repository.AuthorRepository;
import org.springframework.stereotype.Service;
@Service
public class BookstoreService {
private final AuthorRepository authorRepository;
public BookstoreService(AuthorRepository authorRepository) {
this.authorRepository = authorRepository;
}
public List<AuthorDto> fetchByGenre() {
return authorRepository.findByGenre("Anthology");
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P105_DtoRecordConstructor/src/main/java/com/bookstore/repository/AuthorRepository.java | Chapter04/P105_DtoRecordConstructor/src/main/java/com/bookstore/repository/AuthorRepository.java | package com.bookstore.repository;
import com.bookstore.dto.AuthorDto;
import java.util.List;
import com.bookstore.entity.Author;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;
@Repository
public interface AuthorRepository extends JpaRepository<Author, Long> {
@Transactional(readOnly = true)
List<AuthorDto> findByGenre(String genre);
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P105_DtoRecordConstructor/src/main/java/com/bookstore/entity/Author.java | Chapter04/P105_DtoRecordConstructor/src/main/java/com/bookstore/entity/Author.java | package com.bookstore.entity;
import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.GenerationType;
import jakarta.persistence.Id;
import java.io.Serializable;
@Entity
public class Author implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private int age;
private String name;
private String genre;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getGenre() {
return genre;
}
public void setGenre(String genre) {
this.genre = genre;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@Override
public String toString() {
return "Author{" + "id=" + id + ", age=" + age
+ ", name=" + name + ", genre=" + genre + '}';
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P104_JavaRecordsInTemplates/src/main/java/modern/challenge/MainApplication.java | Chapter04/P104_JavaRecordsInTemplates/src/main/java/modern/challenge/MainApplication.java | package modern.challenge;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class MainApplication {
public static void main(String[] args) {
SpringApplication.run(MainApplication.class, args);
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P104_JavaRecordsInTemplates/src/main/java/modern/challenge/controller/BookstoreController.java | Chapter04/P104_JavaRecordsInTemplates/src/main/java/modern/challenge/controller/BookstoreController.java | package modern.challenge.controller;
import modern.challenge.service.BookstoreService;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.ui.Model;
@Controller
public class BookstoreController {
private final BookstoreService bookstoreService;
public BookstoreController(BookstoreService bookstoreService) {
this.bookstoreService = bookstoreService;
}
@GetMapping("/bookstore")
public String bookstorePage(Model model) {
model.addAttribute("authors", bookstoreService.fetchAuthors());
return "bookstore";
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P104_JavaRecordsInTemplates/src/main/java/modern/challenge/service/BookstoreService.java | Chapter04/P104_JavaRecordsInTemplates/src/main/java/modern/challenge/service/BookstoreService.java | package modern.challenge.service;
import java.util.List;
import org.springframework.stereotype.Service;
import modern.challenge.record.Author;
import modern.challenge.record.Book;
@Service
public class BookstoreService {
public List<Author> fetchAuthors() {
List<Author> authors = List.of(
new Author("Joana Nimar", "History", List.of(
new Book("History of a day", "JN-001"),
new Book("Prague history", "JN-002")
)),
new Author("Mark Janel", "Horror", List.of(
new Book("Carrie", "MJ-001"),
new Book("House of pain", "MJ-002")
)
));
return authors;
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P104_JavaRecordsInTemplates/src/main/java/modern/challenge/record/Book.java | Chapter04/P104_JavaRecordsInTemplates/src/main/java/modern/challenge/record/Book.java | package modern.challenge.record;
public record Book(String title, String isbn) {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P104_JavaRecordsInTemplates/src/main/java/modern/challenge/record/Author.java | Chapter04/P104_JavaRecordsInTemplates/src/main/java/modern/challenge/record/Author.java | package modern.challenge.record;
import java.util.List;
public record Author(String name, String genre, List<Book> books) {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P105_DtoRecordJbcTemplate/src/main/java/com/bookstore/MainApplication.java | Chapter04/P105_DtoRecordJbcTemplate/src/main/java/com/bookstore/MainApplication.java | package com.bookstore;
import com.bookstore.jdbcTemplate.dto.AuthorDto;
import java.util.List;
import com.bookstore.service.BookstoreService;
import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
@SpringBootApplication
public class MainApplication {
private final BookstoreService bookstoreService;
public MainApplication(BookstoreService bookstoreService) {
this.bookstoreService = bookstoreService;
}
public static void main(String[] args) {
SpringApplication.run(MainApplication.class, args);
}
@Bean
public ApplicationRunner init() {
return args -> {
List<AuthorDto> authors = bookstoreService.fetchAuthorsWithBooksViaJdbcTemplateToDto();
System.out.println("Number of authors:" + authors.size());
for (AuthorDto author : authors) {
System.out.println("Author name: " + author.name()
+ " | Age: " + author.age() + " | Books: " + author.books());
}
};
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P105_DtoRecordJbcTemplate/src/main/java/com/bookstore/service/BookstoreService.java | Chapter04/P105_DtoRecordJbcTemplate/src/main/java/com/bookstore/service/BookstoreService.java | package com.bookstore.service;
import com.bookstore.jdbcTemplate.dto.AuthorDto;
import com.bookstore.jdbcTemplate.dto.AuthorExtractor;
import java.util.List;
import org.springframework.stereotype.Service;
@Service
public class BookstoreService {
private final AuthorExtractor authorExtractor;
public BookstoreService(AuthorExtractor authorExtractor) {
this.authorExtractor = authorExtractor;
}
public List<AuthorDto> fetchAuthorsWithBooksViaJdbcTemplateToDto() {
return authorExtractor.extract();
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P105_DtoRecordJbcTemplate/src/main/java/com/bookstore/jdbcTemplate/dto/AuthorDto.java | Chapter04/P105_DtoRecordJbcTemplate/src/main/java/com/bookstore/jdbcTemplate/dto/AuthorDto.java | package com.bookstore.jdbcTemplate.dto;
import java.util.List;
public record AuthorDto(Long id, String name, int age, List<BookDto> books) {
public void addBook(BookDto book) {
books().add(book);
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P105_DtoRecordJbcTemplate/src/main/java/com/bookstore/jdbcTemplate/dto/BookDto.java | Chapter04/P105_DtoRecordJbcTemplate/src/main/java/com/bookstore/jdbcTemplate/dto/BookDto.java | package com.bookstore.jdbcTemplate.dto;
public record BookDto(Long id, String title) {} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P105_DtoRecordJbcTemplate/src/main/java/com/bookstore/jdbcTemplate/dto/AuthorExtractor.java | Chapter04/P105_DtoRecordJbcTemplate/src/main/java/com/bookstore/jdbcTemplate/dto/AuthorExtractor.java | package com.bookstore.jdbcTemplate.dto;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;
@Repository
@Transactional(readOnly = true)
public class AuthorExtractor {
private final JdbcTemplate jdbcTemplate;
public AuthorExtractor(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
public List<AuthorDto> extract() {
String sql = "SELECT a.id, a.name, a.age, b.id, b.title "
+ "FROM author a INNER JOIN book b ON a.id = b.author_id";
List<AuthorDto> result = jdbcTemplate.query(sql, (ResultSet rs) -> {
final Map<Long, AuthorDto> authorsMap = new HashMap<>();
while (rs.next()) {
Long authorId = (rs.getLong("id"));
AuthorDto author = authorsMap.get(authorId);
if (author == null) {
author = new AuthorDto(rs.getLong("id"), rs.getString("name"),
rs.getInt("age"), new ArrayList());
}
BookDto book = new BookDto(rs.getLong("id"), rs.getString("title"));
author.addBook(book);
authorsMap.putIfAbsent(author.id(), author);
}
return new ArrayList<>(authorsMap.values());
});
return result;
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P92_RecordMultipleCntrs/src/main/java/modern/challenge/MelonRecord.java | Chapter04/P92_RecordMultipleCntrs/src/main/java/modern/challenge/MelonRecord.java | package modern.challenge;
import java.util.HashSet;
import java.util.Set;
public record MelonRecord(String type, float weight) {
private static final String DEFAULT_MELON_TYPE = "Crenshaw";
private static final float DEFAULT_MELON_WEIGHT = 1000;
private static Set<String> countries = new HashSet<>();
// using the compact constructor specific to records
public MelonRecord {
if (type == null) {
throw new IllegalArgumentException("The melon's type cannot be null");
}
if (weight < 1000 || weight > 10000) {
throw new IllegalArgumentException("The melon's weight must be between 1000 and 10000 grams");
}
}
MelonRecord() {
this(DEFAULT_MELON_TYPE, DEFAULT_MELON_WEIGHT);
}
MelonRecord(String type) {
this(type, DEFAULT_MELON_WEIGHT);
}
MelonRecord(float weight) {
this(DEFAULT_MELON_TYPE, weight);
}
MelonRecord(String type, int weight, String country) {
this(type, weight);
MelonRecord.countries.add(country);
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P92_RecordMultipleCntrs/src/main/java/modern/challenge/Main.java | Chapter04/P92_RecordMultipleCntrs/src/main/java/modern/challenge/Main.java | package modern.challenge;
public class Main {
public static void main(String[] args) {
MelonRecord melon1 = new MelonRecord("Cantaloupe", 2600);
MelonRecord melon2 = new MelonRecord("Horned", 1700, "Africa");
MelonRecord melon3 = new MelonRecord("Apollo", 2600, "Malaysia");
MelonRecord melon4 = new MelonRecord("Hemi", 1600);
MelonRecord melon5 = new MelonRecord("Hemi");
MelonRecord melon6 = new MelonRecord(1600);
MelonRecord melon7 = new MelonRecord();
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P99_RecordPatternInstanceofGuarded/src/main/java/modern/challenge/Hospital.java | Chapter04/P99_RecordPatternInstanceofGuarded/src/main/java/modern/challenge/Hospital.java | package modern.challenge;
import java.time.LocalDate;
public final class Hospital {
private Hospital() {
throw new AssertionError("Cannot be instantiated");
}
public static String cabinet(Staff staff) {
/*
if (staff instanceof Doctor dr
&& dr.specialty().equals("Dermatology")) {
return "The cabinet of " + dr.specialty() + " is currently under renovation";
}
*/
if (staff instanceof Doctor(String name, String specialty)
&& specialty.equals("Dermatology")) {
return "The cabinet of " + specialty + " is currently under renovation";
}
if (staff instanceof Doctor(String name, String specialty)
&& (specialty.equals("Allergy") && (name.equals("Kyle Ulm")))) {
return "The cabinet of " + specialty + " is closed. The doctor "
+ name + " is on holiday.";
}
if (staff instanceof Doctor(String name, String specialty)
&& (specialty.equals("Allergy") && (name.equals("John Hora")))) {
return "The cabinet of " + specialty + " is open. The doctor "
+ name + " is ready to receive patients.";
}
if (staff instanceof Resident(String rsname,
Doctor(String drname, String specialty))
&& (specialty.equals("Dermatology") && rsname.equals("Mark Oil"))) {
return "Cabinet of " + specialty + ". Doctor "
+ drname + " and resident " + rsname + " are ready to receive patients.";
}
return "Cabinet closed";
}
public static String reception(Object o) {
if(o instanceof Patient(var ptname, var npi,
Appointment(var date,
Doctor (var drname, var specialty)))
&& (ptname.equals("Alicia Goy") && npi == 1234567890 && LocalDate.now().equals(date))) {
return "The doctor " + drname + " from " + specialty + " is ready for you " + ptname;
}
return "";
}
} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P99_RecordPatternInstanceofGuarded/src/main/java/modern/challenge/Patient.java | Chapter04/P99_RecordPatternInstanceofGuarded/src/main/java/modern/challenge/Patient.java | package modern.challenge;
public record Patient(String name, int npi, Appointment appointment) {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P99_RecordPatternInstanceofGuarded/src/main/java/modern/challenge/Resident.java | Chapter04/P99_RecordPatternInstanceofGuarded/src/main/java/modern/challenge/Resident.java | package modern.challenge;
public record Resident(String name, Doctor doctor) implements Staff {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P99_RecordPatternInstanceofGuarded/src/main/java/modern/challenge/Staff.java | Chapter04/P99_RecordPatternInstanceofGuarded/src/main/java/modern/challenge/Staff.java | package modern.challenge;
public interface Staff {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P99_RecordPatternInstanceofGuarded/src/main/java/modern/challenge/Appointment.java | Chapter04/P99_RecordPatternInstanceofGuarded/src/main/java/modern/challenge/Appointment.java | package modern.challenge;
import java.time.LocalDate;
public record Appointment(LocalDate date, Doctor doctor) {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P99_RecordPatternInstanceofGuarded/src/main/java/modern/challenge/Doctor.java | Chapter04/P99_RecordPatternInstanceofGuarded/src/main/java/modern/challenge/Doctor.java | package modern.challenge;
public record Doctor(String name, String specialty) implements Staff {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P99_RecordPatternInstanceofGuarded/src/main/java/modern/challenge/Main.java | Chapter04/P99_RecordPatternInstanceofGuarded/src/main/java/modern/challenge/Main.java | package modern.challenge;
import java.time.LocalDate;
public class Main {
public static void main(String[] args) {
Doctor dr1 = new Doctor("John Beer", "Dermatology");
Doctor dr2 = new Doctor("Kyle Ulm", "Allergy");
Doctor dr3 = new Doctor("John Hora", "Allergy");
Resident rs = new Resident("Mark Oil", dr1);
Patient pt = new Patient("Alicia Goy", 1234567890,
new Appointment(LocalDate.now(),
new Doctor("Rares Masdd", "Rheumatology")));
System.out.println(Hospital.cabinet(dr1));
System.out.println(Hospital.cabinet(dr2));
System.out.println(Hospital.cabinet(dr3));
System.out.println(Hospital.cabinet(rs));
System.out.println(Hospital.reception(pt));
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P104_JavaRecordsInControllers/src/main/java/modern/challenge/MainApplication.java | Chapter04/P104_JavaRecordsInControllers/src/main/java/modern/challenge/MainApplication.java | package modern.challenge;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class MainApplication {
public static void main(String[] args) {
SpringApplication.run(MainApplication.class, args);
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P104_JavaRecordsInControllers/src/main/java/modern/challenge/controller/BookstoreController.java | Chapter04/P104_JavaRecordsInControllers/src/main/java/modern/challenge/controller/BookstoreController.java | package modern.challenge.controller;
import java.util.List;
import modern.challenge.service.BookstoreService;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import modern.challenge.record.Author;
@RestController
public class BookstoreController {
private final BookstoreService bookstoreService;
public BookstoreController(BookstoreService bookstoreService) {
this.bookstoreService = bookstoreService;
}
@GetMapping("/authors")
public List<Author> fetchAuthors() {
return bookstoreService.fetchAuthors();
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P104_JavaRecordsInControllers/src/main/java/modern/challenge/service/BookstoreService.java | Chapter04/P104_JavaRecordsInControllers/src/main/java/modern/challenge/service/BookstoreService.java | package modern.challenge.service;
import java.util.List;
import org.springframework.stereotype.Service;
import modern.challenge.record.Author;
import modern.challenge.record.Book;
@Service
public class BookstoreService {
public List<Author> fetchAuthors() {
List<Author> authors = List.of(
new Author("Joana Nimar", "History", List.of(
new Book("History of a day", "JN-001"),
new Book("Prague history", "JN-002")
)),
new Author("Mark Janel", "Horror", List.of(
new Book("Carrie", "MJ-001"),
new Book("House of pain", "MJ-002")
)
));
return authors;
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P104_JavaRecordsInControllers/src/main/java/modern/challenge/record/Book.java | Chapter04/P104_JavaRecordsInControllers/src/main/java/modern/challenge/record/Book.java | package modern.challenge.record;
public record Book(String title, String isbn) {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P104_JavaRecordsInControllers/src/main/java/modern/challenge/record/Author.java | Chapter04/P104_JavaRecordsInControllers/src/main/java/modern/challenge/record/Author.java | package modern.challenge.record;
import java.util.List;
public record Author(String name, String genre, List<Book> books) {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P98_RecordPatternSwitch/src/main/java/modern/challenge/Hospital.java | Chapter04/P98_RecordPatternSwitch/src/main/java/modern/challenge/Hospital.java | package modern.challenge;
import java.time.LocalDate;
public final class Hospital {
private Hospital() {
throw new AssertionError("Cannot be instantiated");
}
public static String cabinet(Staff staff) {
/*
return switch(staff) { // type pattern matching
case Doctor dr -> "Cabinet of " + dr.specialty() + ". Doctor: " + dr.name();
case Resident rs -> "Cabinet of " + rs.doctor().specialty() + ". Doctor: "
+ rs.doctor().name() + ", Resident: " + rs.name();
default -> "Cabinet closed";
};
*/
/*
return switch(staff) { // record pattern matching
case Doctor(String name, String specialty) -> "Cabinet of " + specialty + ". Doctor: " + name;
case Resident(String rsname, Doctor(String drname, String specialty)) -> "Cabinet of " + specialty + ". Doctor: "
+ drname + ", Resident: " + rsname;
default -> "Cabinet closed";
};
*/
return switch(staff) { // record pattern matching
case Doctor(var name, var specialty) -> "Cabinet of " + specialty + ". Doctor: " + name;
case Resident(var rsname, Doctor(var drname, var specialty)) -> "Cabinet of " + specialty + ". Doctor: "
+ drname + ", Resident: " + rsname;
default -> "Cabinet closed";
};
}
public static String reception(Object o) {
return switch(o) {
case Patient(String ptname, int npi,
Appointment(LocalDate date,
Doctor (String drname, String specialty))) ->
"Patient " + ptname + " (NPI: " + npi + ") has an appointment at "
+ date + " to the doctor " + drname + " (" + specialty + ").";
default -> "";
};
/*
return switch(o) {
case Patient(String ptname, int npi, Appointment ap) ->
"Patient " + ptname + " (NPI: " + npi + ") has an appointment at "
+ ap.date() + " to the doctor " + ap.doctor().name() + " (" + ap.doctor().specialty() + ").";
default -> "";
};
*/
/*
return switch(o) {
case Patient(var ptname, var npi, var ap) ->
"Patient " + ptname + " (NPI: " + npi + ") has an appointment at "
+ ap.date() + " to the doctor " + ap.doctor().name() + " (" + ap.doctor().specialty() + ").";
default -> "";
};
*/
/*
return switch(o) {
case Patient(var ptname, var npi,
Appointment(var date,
Doctor (var drname, var specialty))) ->
"Patient " + ptname + " (NPI: " + npi + ") has an appointment at "
+ date + " to the doctor " + drname + " (" + specialty + ").";
default -> "";
};
*/
}
} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P98_RecordPatternSwitch/src/main/java/modern/challenge/Patient.java | Chapter04/P98_RecordPatternSwitch/src/main/java/modern/challenge/Patient.java | package modern.challenge;
public record Patient(String name, int npi, Appointment appointment) {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P98_RecordPatternSwitch/src/main/java/modern/challenge/Resident.java | Chapter04/P98_RecordPatternSwitch/src/main/java/modern/challenge/Resident.java | package modern.challenge;
public record Resident(String name, Doctor doctor) implements Staff {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P98_RecordPatternSwitch/src/main/java/modern/challenge/Staff.java | Chapter04/P98_RecordPatternSwitch/src/main/java/modern/challenge/Staff.java | package modern.challenge;
public interface Staff {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P98_RecordPatternSwitch/src/main/java/modern/challenge/Appointment.java | Chapter04/P98_RecordPatternSwitch/src/main/java/modern/challenge/Appointment.java | package modern.challenge;
import java.time.LocalDate;
public record Appointment(LocalDate date, Doctor doctor) {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P98_RecordPatternSwitch/src/main/java/modern/challenge/Doctor.java | Chapter04/P98_RecordPatternSwitch/src/main/java/modern/challenge/Doctor.java | package modern.challenge;
public record Doctor(String name, String specialty) implements Staff {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P98_RecordPatternSwitch/src/main/java/modern/challenge/Main.java | Chapter04/P98_RecordPatternSwitch/src/main/java/modern/challenge/Main.java | package modern.challenge;
import java.time.LocalDate;
public class Main {
public static void main(String[] args) {
Doctor dr = new Doctor("John Beer", "Dermatology");
Resident rs = new Resident("Mark Oil", dr);
Patient pt = new Patient("Alicia Goy", 1234567890,
new Appointment(LocalDate.now(),
new Doctor("Rares Masdd", "Rheumatology")));
System.out.println(Hospital.cabinet(dr));
System.out.println(Hospital.cabinet(rs));
System.out.println(Hospital.reception(pt));
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P93_RecordAndInterfaces/src/main/java/modern/challenge/MelonRecord.java | Chapter04/P93_RecordAndInterfaces/src/main/java/modern/challenge/MelonRecord.java | package modern.challenge;
public record MelonRecord(String type, float weight) implements PestInspector {
@Override
public void exterminatePest() {
if (detectPest()) {
System.out.println("All pests have been exterminated");
} else {
System.out.println("This melon is clean, no pests have been found");
}
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P93_RecordAndInterfaces/src/main/java/modern/challenge/Main.java | Chapter04/P93_RecordAndInterfaces/src/main/java/modern/challenge/Main.java | package modern.challenge;
public class Main {
public static void main(String[] args) {
MelonRecord melon = new MelonRecord("Cantaloupe", 2600);
System.out.println(melon);
System.out.println(melon.weight() + " g");
melon.exterminatePest();
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P93_RecordAndInterfaces/src/main/java/modern/challenge/PestInspector.java | Chapter04/P93_RecordAndInterfaces/src/main/java/modern/challenge/PestInspector.java | package modern.challenge;
public interface PestInspector {
public default boolean detectPest() {
return Math.random() > 0.5d;
}
public void exterminatePest();
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P103_UnnamedPatternSwitch1/src/main/java/modern/challenge/Hospital.java | Chapter04/P103_UnnamedPatternSwitch1/src/main/java/modern/challenge/Hospital.java | package modern.challenge;
public final class Hospital {
private Hospital() {
throw new AssertionError("Cannot be instantiated");
}
public static String cabinet(Staff staff) {
/*
return switch(staff) {
case Doctor(String name, String specialty) ->
"The cabinet of " + specialty + " is currently under renovation";
case Resident(String name, Doctor dr) ->
"The resident of this cabinet is : " + name;
default -> "Cabinet closed";
};
*/
return switch(staff) {
case Doctor(_, String specialty) ->
"The cabinet of " + specialty + " is currently under renovation";
case Resident(String name, _) ->
"The resident of this cabinet is : " + name;
default -> "Cabinet closed";
};
}
public static String reception(Object o) {
/*
return switch(o) {
case Patient(String ptname, int npi,
Appointment(LocalDate date,
Doctor (String drname, String specialty))) ->
"Patient " + ptname + " has an appointment";
default -> "";
};
*/
return switch(o) {
case Patient(String ptname, _, _) ->
"Patient " + ptname + " has an appointment";
default -> "";
};
}
} | java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P103_UnnamedPatternSwitch1/src/main/java/modern/challenge/Patient.java | Chapter04/P103_UnnamedPatternSwitch1/src/main/java/modern/challenge/Patient.java | package modern.challenge;
public record Patient(String name, int npi, Appointment appointment) {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P103_UnnamedPatternSwitch1/src/main/java/modern/challenge/Resident.java | Chapter04/P103_UnnamedPatternSwitch1/src/main/java/modern/challenge/Resident.java | package modern.challenge;
public record Resident(String name, Doctor doctor) implements Staff {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P103_UnnamedPatternSwitch1/src/main/java/modern/challenge/Staff.java | Chapter04/P103_UnnamedPatternSwitch1/src/main/java/modern/challenge/Staff.java | package modern.challenge;
public interface Staff {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P103_UnnamedPatternSwitch1/src/main/java/modern/challenge/Appointment.java | Chapter04/P103_UnnamedPatternSwitch1/src/main/java/modern/challenge/Appointment.java | package modern.challenge;
import java.time.LocalDate;
public record Appointment(LocalDate date, Doctor doctor) {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P103_UnnamedPatternSwitch1/src/main/java/modern/challenge/Doctor.java | Chapter04/P103_UnnamedPatternSwitch1/src/main/java/modern/challenge/Doctor.java | package modern.challenge;
public record Doctor(String name, String specialty) implements Staff {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P103_UnnamedPatternSwitch1/src/main/java/modern/challenge/Main.java | Chapter04/P103_UnnamedPatternSwitch1/src/main/java/modern/challenge/Main.java | package modern.challenge;
import java.time.LocalDate;
public class Main {
public static void main(String[] args) {
Doctor dr = new Doctor("John Beer", "Dermatology");
Resident rs = new Resident("Mark Oil", dr);
Patient pt = new Patient("Alicia Goy", 1234567890,
new Appointment(LocalDate.now(),
new Doctor("Rares Masdd", "Rheumatology")));
System.out.println(Hospital.cabinet(dr));
System.out.println(Hospital.cabinet(rs));
System.out.println(Hospital.reception(pt));
}
}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P102_StrShortener/src/main/java/modern/challenge/Literal.java | Chapter04/P102_StrShortener/src/main/java/modern/challenge/Literal.java | package modern.challenge;
record Literal(String text) implements Str {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
PacktPublishing/Java-Coding-Problems-Second-Edition | https://github.com/PacktPublishing/Java-Coding-Problems-Second-Edition/blob/47b7c834407a607580baf8e3a23c1c24c24b8bc0/Chapter04/P102_StrShortener/src/main/java/modern/challenge/Str.java | Chapter04/P102_StrShortener/src/main/java/modern/challenge/Str.java | package modern.challenge;
interface Str {}
| java | MIT | 47b7c834407a607580baf8e3a23c1c24c24b8bc0 | 2026-01-05T02:37:06.170961Z | false |
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