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Java : How do I do to overwrite a method with the one i just selected ? For example : First I typebut then , I reminded that the method was another one , and the cursor was after the word some and before Method , when I press Ctrl+Space again , it shows up some methods , when i hit enter , my method now is something li... | Ctrl+Space overwrite method with the one selected |
Java : I was trying to replicate a bug by using the same instance of SimpleDateFormat across multiple threads . However I got stuck with another problem and did not find any answers to it . This simple code block replicates the issues I am seeing.The results of this operations under java 7 ( 1.7_0_21 ) is as follows As... | new SimpleDateFormat always returns same reference for a given dateFormat |
Java : Do you need to call remove on a thread local if you are not deploying in a server environment , even if the app uses a cached thread pool ? <code> public static ThreadLocal < Integer > i = new ThreadLocal < Integer > ( ) { { public Integer initialValue ( ) { return 3 ; } } ; | thread local remove method |
Java : See Update below to show potential workaroundOur application consumes 2 topics as KTables , performs a left join , and outputs to a topic . During testing , we found that this works as expected when our output topic has only 1 partition . When we increase the number of partitions , we notice that the number of m... | KTable-KTable foreign-key join not producing all messages when topics have more than one partition |
Java : I am new to java and trying to understand the following . The length of the arrays is not same . The code still executes without any errors . I dont understand why . If someone could clarify . <code> public class Practice { public static void main ( String [ ] args ) { int [ ] [ ] a = { { 1,2,3 } , { 4,5 } } ; a... | Why does the following code compile without error ? |
Java : I have searched and searched and this is destroying me . I have this : The emailFormUrl returns the URL correctly but the parameters have been stripped.Which speaks of : For some reason , the id is being stripped , this leaves me with a validation error and does n't complete the action that I require . As I am a... | s : form tag action parameters being removed |
Java : Help me optimize the algorithm . I have a heap in the array.Each number in the array indicates a parent . Root is -1.I need to find the depth of heap.Example : Array is 4 -1 4 1 1The answer is 3.It 's my codeWhere pos - position of root.I also solved this problem with recursion . But tests give me `` Time limit ... | Find heap depth faster than O ( n^2 ) |
Java : Take a look at this code ( from here ) There are two parallel inheritance trees , for a parent class and an associated class . The problem is with line 23 : ( ( AssocAConcrete ) myA ) .salute ( ) ; It is a pain and I have that kind of thing all over my code . Even though that line is part of the concrete impleme... | Inheritance and casting : is this good java ? |
Java : I 'm currently using Roaster to generate interfaces , but my interface has generic types bound to it.Here 's what I was trying to generate them to begin with : But the above results in generated code that looks ( something ) like this : What I actually want is for the generic to be bound to JpaRepository . How d... | Using Roaster , how can I generate an interface with a specific generic type ( or types ) ? |
Java : I have a class that contains a cache ( Set ) , and the cache is built on instantiation . I 'm confused which exception/error should I throw if building cache fail ( can not connect to database or some ) .One exception comes in my mind is ExceptionInInitializerError , but javadoc says it is thrown on initialize s... | Which exception should I throw when building cache fail ? |
Java : I am looking for a clean and safe way to ensure tha a field of a class will never be set to null . I would like the field value to be set once in the class constructor and never modified later . I think that he readonly keyword in C # allows this . Is there a way to do the same in Java ? <code> class foo { priva... | How to ensure that a field will never be null in a Java class |
Java : Long story short : Why is the following not possible in Java ? Note : I do n't have any specific use case right now , rather I am just trying to understand why this is not allowed.At first I thought because the compiler can not assert if A can accept generics parameter because after compiling A , due to type era... | Why is second level generics not possible in Java |
Java : I 've been staring at the screen the last 5 minutes and ca n't seem to figure out what I 'm doing wrong : I 'm surprised why the String [ ] can not be converted to List < String > to initialize the HashSet < String > with it.I 'm getting the build error : What 's wrong with my assignment ? <code> class Example {... | Can not create Set from String array |
Java : From the Matrix Chain Multiplication page on Wikipedia , there is this fragment of Java code : Is n't m = new int [ n ] [ n ] ; already allocating memory space of size n in both its dimensions so this step in the loop m [ i ] = new int [ n ] ; is actually redundant because all it does is reallocate the second di... | Is this a redundant allocation of memory space in a multi dimensional array ? |
Java : I came across the following code , a simple example of adding elements to ListI expected it to throw an ClassCastException , but rather it wrote this to the console which looks weird . When i tried : I got a compile time error . I would be grateful if someone could explain how the String objects are added to the... | Does ArrayList < Integer > allow adding of String ? |
Java : I 'm working on an assignment dealing with class inheritance and have everything done and working properly except for a string format method . The output of the program should look like this : but it is printing like this : The problem is that in the output , `` Earnings : $ 450.00 '' is printing before `` with ... | Java : Is it possible to exclude taking something from a super class |
Java : I got simple code , maybe the problem relies on the given format string or on the timezone . So here is the code : The result is : Thu Jan 01 00:00:00 EET 1970-10800000 -- > should be 0 as we give 00:00 hours in and the other time elements remain default.//EditYes the problem is with timezone to fix this use df.... | Date parsing from string to long gives wrong result |
Java : Possible Duplicate : Java - boolean primitive type - size I 've designed this program to calculate the size of a boolean in Java.When I run the program , it says that the size is 1.0000016 bytes . Now , the Oracle Java documentation says that the size of a boolean is `` not defined '' . [ See link ] .Why is this... | Program to calculate the size of a boolean variable |
Java : Here is a java snippet : And It behave different according to different JDKsin Oracle JDK 1.7 output is : in OpenJDK 1.6 output is also : but in Oracle JDK 1.6 output is : as the JavaDoc for this String # intern method indicates the output : should be expected , but neither three JDKs produce this . and Why Orac... | Why String.intern ( ) behave differently in Oracle JDK 1.7 ? |
Java : I am trying to send some work from IntentService to BroadcastReceiver by using .putExtra ( ) and sendBroadcast ( ) , so I have own class called `` Message '' , which extends HashMap < String , String > and implements Serializable.And I am sending it like this : And receiving like this : But here I always get thi... | Casting Serilizable to derivation of HashMap |
Java : I recently learned that there are Class representations for the primitive types in the JVM . For example , int.class , double.class , and even a void.class.What I do n't understand is why these are there . They do n't seem to serve any functional role . Using reflection , I searched through the classes , and the... | What is the use/purpose of primitive type classes ? |
Java : I am using the org-netbeans-lib-cvsclient.jar to execute various cvs commands in a java class that communicates with CVS . I am able to do a cvs checkout command , add , commit , etc . However , I need to find out which command is equivalent to the cvs ls -R command.Here is the code I wrote that allows to do a c... | Is it possible to checkout only the directory structure in cvsclient in Java ? |
Java : Hi i am attempting to discover why my program 's usually run slower than i want them so thank you in advance for your help ! I have for example a piece of code that i would like some insight intoin Line # 2 . I create a new Object . This will happen thousands of times in my program . Do i specifically have to nu... | Must you set references to null for garbage collection to work |
Java : I 'm trying to write a program that in the Main class one can initiate unknown amount of new threads.Each thread in turn should call to a Singleton Copier class which should call a file transfer action.My goal is , regardless the amount of threads requests , is to limit the number of concurrent transfers to 2 tr... | Semaphore - why my threads are running one after the other and not in concurrent ? |
Java : I found out , that for example this line has a very very long execution time : If I reduce the amount of dots at the start of the String the execution time gets lower ( seems like it 's exponential ) . Here is the suspended thread 's stack trace : Why does this happen ? <code> System.out.println ( `` .. .. .. ..... | Why does this regex take a long time to execute ? |
Java : Possible Duplicate : NullPointerException through auto-boxing-behavior of Java ternary operator The following code uses simple conditional operators.This code compiles fine . All the expressions ultimately attempt to assign null to Integer type variables exp1 , exp2 and exp3 respectively.The first two cases do n... | Conditional operators in Java throw an unexpected NullPointerException |
Java : Please help me understand this code . I am new to java . <code> // C.javaclass C { public static void main ( String arg [ ] ) { System.out.println ( `` A '' +new C ( ) ) ; } public String toString ( ) { System.out.print ( `` B '' ) ; return `` C '' ; } } // output : // BAC | Java - Why the following code print out `` BAC '' , instead of `` ABC '' ? |
Java : I learned that if I have two classes : I can cast from a List < A > to List < B > by doing this : This would generate a warning , but it works . However , I read that this is not recommended . Is it true in that case ? If I know it 's returning me a List < B > , why making this cast is such a bad practice ? Plea... | Why is casting from List < A > to List < B > not recommended ? |
Java : Which of these is more performant , or ( if equivalent ) which one reads better ? I 'm trying to match everything inside a pair of parentheses.To me , the second reads better but uses the possibly confusing reluctant quantifier , and I 'm unsure if that causes a performance loss.EDITDo n't miss the answer which ... | Java Regex Performance : Reluctant Quantifier or Character Class ? |
Java : In RandomAccess marker interface description it is written : In collection class synchronisedList method there is a check for RandomAccess & if success create SynchronizedRandomAccessList object but their also no details regarding algorithm . When does this algorithm apply and where ( is it a native code ) ? <co... | When does algorithms for manipulating random access lists is applied ? |
Java : I 'm working on a project using rxjava1 and I have an Observable chain that occasionally will contain thousands of observables merged or concatted together . When this happens a StackOverflow exception will occur and we will get something like this : And the stacktrace will continue for hundreds of lines . The o... | RxJava1 StackOverflow Exception With Too Many Observables |
Java : I have a class contains 10 methods which are doing almost the same things apart from one key event . Two examples are given below : As you can see from the above methods , they are similar apart from calling different methods provided by requestBuilder . The rest 8 are similar too . There is a lot duplicated cod... | remove duplication |
Java : I 'm reading HTTP request from socket input streamIt 's working but findbugs gives the following bug : Dereference of the result of readLine ( ) without nullcheck . Request ends with `` '' not eof . So how can I check null value here ? <code> StringBuilder request = new StringBuilder ( ) ; String inputLine ; whi... | Reading http request from socket with null check java |
Java : I know that java compiler can actually reorder code instructions . But can java reorder function calls ? For example : <code> ... //these lines may be reordereda=7 ; b=5 ; ... //but what about this ? callOne ( ) ; callTwo ( ) ; | Could a Java compiler reorder function calls ? |
Java : Question : Is it possible to access elements annotated with a @ Target ( ElementType.TYPE_USE ) annotation via an annotation processor ? Is it possible to access the annotated type bounds via an annotation processor ? Links to related documentation I missed are highly appreciated.Context : The annotation : An ex... | How to access TypeUse annotation via AnnotationProcessor |
Java : This prints Number Class Type.I understand the rules of wrapper class method overloading : If you are passing a primitive data type as an argument to the methodcall , the compiler first checks for a method definition which takes thesame data type as an argument.If such a method does not exist , then it checks fo... | Why does n't my primitive-type-argumented method override the wrapper-type-argumented super class method ? |
Java : I want to compile my code down to Java version 1.0.I managed to compile down to 1.1 : But the target option does not seem to accept 1.0 : How do I target JDK 1.0 ? I want my .class and .jar file to work as many systems as possible , including very old ones , including JDK 1.0 . ( I do n't have access to a system... | How to compile to target Java 1.0 |
Java : I found cache mechanism is improved in jdk 1.6 or above jdk versions.In jdk 1.5 the cache array in Integer is a fixed one , seeIn jdk 1.6 or above version , an method named getAndRemoveCacheProperties and an IntegerCache.high property have been added to Integer class , like , // value of java.lang.Integer.Intege... | What is the advantage of cache mechanism change of Integer class in JDK 1.6 or above ? |
Java : I 'm following the spring tutorial.In section `` 3.2 . Add some classes for business logic '' an interface ProductManager is created : Then a SimpleProductManager implementation class is created : The implementation class adds an extra method setProducts ( ) . Should the interface ProductManager not also have a ... | Bad practice in this spring tutorial ? |
Java : My question may be basic , but I am wondering how the pipe operator works in the following contexts in Android : We can set multiple input types in layout : We can set multiple flags to an intent as follows : Also we can set some properties as follows : There are multiple instances where we can see such examples... | How does the pipe ( | ) operator work in Android while setting some properties ? |
Java : We have a class in our codebase currently that uses the synchronized keyword at the method level to ensure data consistency in multithreaded operations . It looks something like this : The nice thing about this is that anyone using the class gets the synchronization for free . When you create an instance of Foo ... | Is there any compile-time mechanism in Java to attempt to ensure that use of a particular class is always synchronized ? |
Java : I 'm examining a source code written by someone else . I 've encountered something like this : What does this expression object._ ( `` a string here '' ) mean ? <code> x = new MyObject ( ) ; x._ ( `` somestring '' ) | What does object._ ( `` a string here '' ) mean ? |
Java : Looking at the JDK source code for LinkedHashMap , I noticed that this class is declared as : why the redundant `` implements Map < K , V > '' ( since HashMap already implements Map ) ? I can not imagine this is a typo ... Thanks . <code> public class LinkedHashMap < K , V > extends HashMap < K , V > implements ... | LinkedHashMap signature |
Java : This I read from the threads : :shared description : By default , variables are private to each thread , and each newly created thread gets a private copy of each existing variable . This module allows you to share variables across different threads ... ( more ) Let 's say I have a shared variable like this : Th... | Perl shared variables atomicity and visibility |
Java : I have these entities : Now , this statement inside Room ... ... will cause that entire Player entity to be fetched from the database . However , I just need its primary key , id , which it should already have ( otherwise how can it fetch the data ? ) .How can I access the lazy Player proxy 's id without trigger... | Hibernate loading a lazy proxy , but I only need the PK |
Java : While investigating a stack trace discrepancy when composing another answer , I came across a behavior I do not understand . Consider the following test program ( this is as far down as I could narrow it ) : Lines 11 and 13 are labelled in the above snippet and it can be run on ideone . The output of that progra... | Mysterious line in stack trace |
Java : Part of a Java program I 'm making asks the user their home country . Another part uses a switch statement , and I get an error . The error is : The operator || is undefined for the argument type ( s ) java.lang.String , java.lang.String . Here 's the method where the problem occurs : How does one use & & and ||... | Using `` || '' in switch statements in java |
Java : I 'm using ph-schematron , a Java library that validates XML documents via ISO Schematron : This library provides 2 ways of XML document validation : Validation via XSLTValidation via Pure SchematronI would love to use the second type , but my Schematron files contain XSLT functions so we MUST use the validation... | Resolving relative paths when using ph-schematron |
Java : I am wondering about JDK9 modules . Say you have the following 3 packages : Classes in package product.impl_a and product.impl_b can only be accessed by classes in package product . The user should only use classes from product package . You can imagine that passing certain flags or properties will decide whethe... | How will JDK9 modules help for 'package-scoped sub-packages ' ? |
Java : I know that you can change the position of a circle in an animation like this ( see also here ) : But is there also a possibility ( this means a Property ) to change the points of a polygon in an animation ? And if not : Which other possibilities do I have to morph a polygon in an animation using JavaFX ? <code>... | JavaFX : How can I change the points of a polygon in an animation ? |
Java : What classes do you use to make string placeholders work ? <code> String template = `` You have % 1 tickets for % d '' , Brr object = new Brr ( template , { new Integer ( 1 ) , new Date ( ) } ) ; object.print ( ) ; | What classes do you use to make string templates ? |
Java : Possible Duplicate : intern ( ) behaving differently in Java 6 and Java 7 While doing example for this questionI noticed a strange behaviour of intern ( ) method when I call intern ( ) method on String thereafter I can use == operator for the Original String.JavaDoc of intern ( ) method : Returns a canonical rep... | Does String.intern ( ) change reference of Original String JDK7 |
Java : I solve algorithmic problems on codeforces and I tried pushing the same solution using java 7 and java 8 and to my surprise using java 8 I got much worse solution.On the last test : Java 7 : time : 373 ms. , memory : 112 KBjava 8 : time : 623 ms. , memory : 3664 KBMy codeWhy is that ? <code> public static void m... | Java 8 bad performance , sorting |
Java : I have some text encrypted and stored in a db using PBE AES_256 . This was initially done using java 1.8.0_65 . After upgrading to latest java , I can no longer decrypt these fields . I have pinpointed the incompatibility to 1.8.0_71 . The release notes state the following : Problem with PBE algorithms using AES... | PBE AES_256 encryption incompatible between java 8 u65 and u71 |
Java : In javax.annotation.processing package there is a interface Processor in which there is a function : The Java API AbstractProcessor implements above interface . Now I created my own processor class : My questions : The API doc tells me the annotations in the process function are the the annotation types requeste... | About the parameter defined in process ( ... ) method of Processor interface |
Java : I 'm writing a program that displays flight information as seen bellow : The problem I have is when using the method : It does n't execute for some reason when normally running , but when I step though the program using the debugger everything executes fine and I get a meaningful output ( not very well formatted... | program works when stepping through but does n't when running |
Java : I am in process of migrating a java project from weblogic 8.1 to weblogic 12c.As per oracle document i have converted below things.After all above changes did generate war file and deployed in weblogic 12c server which throws error like belowCode : <code> 1 . Servicegen converted to jwsc task 2. deployment descr... | Unable to invoke annotation processor - while deploying in Weblogic 12.2.1.2.0 |
Java : Here is my sample code . The query is encoded to UTF-8 : After I run this example I get the following exception : char=324 means decoded ń from queryWhen I read stack trace I found jdk.incubator.http.Stream < T > this method in the class : In this method uri.getQuery ( ) is used which gives us the decoded query ... | Java 9 HttpClient exception when using certain characters in URL query parameters |
Java : How do I use Collectors in order to convert a list of DAOs , to a Map < String , List < Pojo > > daoList looks something like this : I want to groupBy 'team ' attribute and have a list for each team , as follows : Pojo looks like this : This is how I 'm trying to do that , obviously the wrong way : <code> [ 0 ] ... | Use Collectors to convert List to Map of Objects - Java |
Java : I am reading an article about the Java Volatile keyword , got some questions . click hereThe udpate ( ) method writes three variables , of which only days is volatile.The full volatile visibility guarantee means , that when a value is written to days , then all variables visible to the thread are also written to... | Full volatile Visibility Guarantee |
Java : Why ismore strict then This is a follow up on Why is lambda return type not checked at compile time.I found using the method withX ( ) likeproduces the wanted compile time error : The type of getLength ( ) from the type BuilderExample.MyInterface is long , this is incompatible with the descriptor 's return type ... | Why is a type parameter stronger then a method parameter |
Java : I 'm trying to understand add operation of ArrayList Class in Java from here . Here is a portion of code : Steps for the elements insertion are : verify if it does exist enough space before inserting a new element by calling ensureCapacityInternal , in case there is no enough space we call grow operation to incr... | Add an element to ArrayList when there is no space left |
Java : Consider a Dagger module : Context is an object may be connected to e.g . an HTTP sessionthat can not be known at startup , when one would normally create agraph : Given that Module is sufficiently long , it would seem to makesense to first create a graph for Module : and then , on processing a particular reques... | Traceback on Dagger .plus ( ) on incomplete parent |
Java : I have an abstract class called sessions . Lectures and tutorials extend sessions . Then I have a class called enrollment which holds a list of sessions ( Lectures & tutorials ) . How can I loop through the session list in Enrolment and return a list of Lectures only from the session list ? My next question is s... | How to figure out what object is in a abstract list ? |
Java : My standard AppEngine application needs to perform changes in a Google Sheet documents ( among others ) .To achieve this , I need to obtain a credential for service account , and somehow configure that it should act in behalf of a user.This method allows gives me default service account credentials : but it does... | How can I impersonate a user of AppEngine java application operating in G-Suite domain ? |
Java : i try to android 3.0. i upgrade my android project to android studio 3.0 after that i cant run my project and i have this error . i use MultiDex and use java 8. this is my build.gradle and this is my compile error <code> dependencies { compile fileTree ( include : [ '*.jar ' ] , dir : 'libs ' ) compile `` com.an... | Error : Error converting bytecode to dex : Cause : not found : Ljava/lang/Object ; |
Java : Looking at the example above , it seems the main point of generics is to enforce type on a collection . So , instead of having an array of `` Objects '' , which need to be cast to a String at the programmer 's discretion , I enforce the type `` String '' on the collection in the ArrayList . This is new to me but... | Are Java generics mainly a way of forcing static type on elements of a collection ? |
Java : I have the following class : I want to change it to the following definition : Is this change binary compatible ? I.e. , will code that is compiled against the old version of the class work with the new version without reocmpilation ? I know that I need to change SomePrivateSubclassOfFoo , this is ok . I also kn... | Is making return type generic with same erasure binary compatible ? |
Java : So I have a random question when coding the image processing function that involves time complexity . The following is my original snippet of code : And after coming out with that code , I was wondering whether it would be faster not to create 4 temporary variables for floor and ceiling values but , instead , ca... | Difference in time complexity in array addressing in Java |
Java : I was trying to parse a date string using jodatime with a leading '+ ' before the yyyy part . I expected an error to be thrown , but it actually did not throw an error . I got outputs that do n't make any sense instead : Can anyone explain why this is happening ? I expect either an exception , which means '+ ' s... | Weird behaviour of jodatime in parsing some date formats |
Java : Starting with Java 8 so need a bit of time to get used to it . It 's a classical problem , I 've an array of objects that I want to transform.Before Java8 the ideal code would be ( no null pointers ) : What is the best version in Java8 ? <code> P [ ] outputArray = new P [ inputArray.length ] ; for ( int i =0 ; i... | Java 8 - best way converting array elements |
Java : I 'm battling to understand why this is possible . I 'm a java newbie and do n't understand how you can have a collection of any type ( lists or sets ) be of type Example . I 'm battling to understand both the recursive nature of this as well as why this is used . <code> class Example { private Set < Example > s... | Why can you have a HashSet of objects of that class |
Java : So , I have a root process ( running as root ) , and I want it to load another process with a non-root uid.At the moment , I 'm calling seteuid , and setegid , then resettting to root after the process has been created . I found that the process still loads with a uid of root . What should I be using to do this ... | Loading a process as another user ? |
Java : In the function below , what can I use to replace < typedefinition > to make the program print `` O noes ! `` ? <code> public static void main ( String [ ] args ) { Object o = null ; story ( o ) ; } private static void story ( < typedefinition > o ) { if ( o ! = null ) System.out.println ( `` O noes ! `` ) ; els... | Is it possible to call a method with a null parameter but have the argument not be null ? |
Java : I think that question is pretty straight . but here is an examples.Example below is OK . I can take rounding and no truncating was done here.Output : And now number out of range of long : Output : This one troubles me . I can not continue work with completely different number . I would rather get an error or an ... | How to test if value stored in double fit in long ? ( rounding yes , but truncating no ) |
Java : I receive a AbstractMethodError when invoking a method that , I think , should have a default implementation in the target instance.I create a functional interface in three parameters but also derive from java.util.function.Function and provide a default implementation of Function # apply ( .. ) . I then create ... | Java 8 default implementation is not available when instance is passed as its superinterface |
Java : I 'm making application that requires to get data from Facebook.To avoid duplicating code I decided to create a class for GraphRequest . To call the class I useThe problem is GraphApiRequest method always returns object=null and only after that executes request . What should I change to get actual object on call... | Calling Facebook GraphRequest from another class returns null |
Java : I 've done a lot of searching through generic type questions and just have n't found anything that has helped me figure out what I am doing wrong here . I have an interface as follows : Now , the next step is making a class that implements this interface . This particular class is going to use an insertion sort ... | Keeping generic types when implementing in class |
Java : I 'm preparing myself to a Java exam , and I 'm reading `` OCA Java SE 8 Programmer Study Guide ( Exam 1Z0-808 ) '' . In operators section I found this sentence : Shift Operators : A shift operator takes two operands whose type must be convertible to an integer primitive.I felt odd to me so I tested it with long... | Shift operators - operands must be convertible to an integer primitive ? |
Java : Just removed the following code from a colleague 's code : I just want to make sure I did the right thing . Why would someone intentionally write this ? This is exactly what the compiler inserts by default is n't it ? Edit : To clarify : that 's the only constructor.Also , this is not a trick question . The guy ... | Why would someone intentionally implement the default implementation of the default constructor ? |
Java : I recently discovered the `` assert '' statement in Java , and have been littering my software with them as I debug it . My initial instinct was to avoid making control flow statements just to handle assert statements , but then I realized that these control statements would probably be removed during a producti... | Will an iterator surrounding an assert statement affect performance of production build ? |
Java : I have two example class files , one from an example Java app and one from an example C app ( compiled to bytecode using LLJVM ) .Looking at their outputs , I can see through javap -c -p that for initializing the ( static ) fields , the Java app shows the following block : Which is basically the < clinit > metho... | Javap output : difference static { } and public { } |
Java : I can add abstract keyword inside static initialization block , but I ca n't add abstract method as So I can only add abstract class inside static block , as follows : But it does n't sound realistic to add classes hierarchy inside static block which will be in lower access level than private , is there other us... | abstract class inside static block usage |
Java : I want the GUI to change the title of a button from `` Go '' to `` Working ... '' before an object is instantiated and actually does the work . When finished , I want the title of the button to switch back to `` Go . `` Here 's the code : What actually happens in practise is name is instantiated , methodName get... | Operation priority in Java . ( An object instantiates and runs before the GUI is updated ? ) |
Java : I need to declare an instance of Map.class , but the Map is typed ... So I need something like this : This line causes a compile error . What is the clean way of expressing this ? <code> Class < Map < String , String > > clazz = Map.class ; | How to declare a Typed Class in Java ? |
Java : I have seen examples on the site that deal with generics with multiple parameters but none that work for my situation.So here is the deal : I am trying to learn Java generics and have decided to create a simple binary array search utility function . I am testing it out using custom objects and integers . To get ... | Java generics with multiple parameters |
Java : I have the following sealed interface ( Java 15 ) : This interface is implemented by 2 classes : Can someone tell me the difference between final and non-sealed ? final stops me from creating other sub-classes but what behavior does non-sealed apply to Duck ? <code> public sealed interface Animal permits Cat , D... | What is the difference between a final and a non-sealed class in Java 15 's sealed-classes feature ? |
Java : The method of the Arrays class in its implementation navigates through the array argument a following the binarySearch algorithm and converts the elements of a into Comparable and invokes compareTo ( key ) until it either finds a match or runs out of possibilities . I 'm stumped by the implementation however , i... | Why Arrays.binarySearch ( Object [ ] , Object ) takes Object args ? |
Java : This question is probably language-agnostic , but I 'll focus on the specified languages.While working with some legacy code , I often saw examples of the functions , which ( to my mind , obviously ) are doing too much work inside them . I 'm talking not about 5000 LoC monsters , but about functions , which impl... | General function question ( C++ / Java / C # ) |
Java : I 'm having a problem with RxJava , Retrofit and Multi-Window mode ... I 'm calling our own api with Retrofit inside an Activity ( the actual code is a little bit more complex than this ) : When the app is in `` normal '' mode ( full-screen ) everything runs fine ... I can put the app in bg , put it back to fore... | Strange lifecycle callbacks ordering when entering multi-window mode |
Java : I 've read a lot of posts and tried many solutions , but the common point of all posts was that they were all outdated and at least I could n't find a solution that would work on newer versions of Android.Post 1 , Result : intent.getExtras ( ) .getInt ( `` simId '' , -1 ) always returns -1Post 2 , Result : inten... | Detecting target SimCard of incoming call in Multi-Sim devices |
Java : I wrote a simple Util method to convert a String in Java to util.Date . What I am not able to figure out is why the method works for the first input , and fails for the second one , given that the inputs are identical : Code : Output : Logically , the output should 've been Sat Feb 04 13:17:00 CET 2012 going by ... | Inconsistent ParseExeption with Data Format in Java |
Java : Would it be considered worsening the future readability of the code if I used them throughout the code ? For example using : so I can use this code <code> import static java.lang.Integer . * ; int a = parseInt ( scanner.nextLine ( ) ) ; | Using static imports and code readability quality ? |
Java : For example : When e.printStackTrace ( ) executes , are we guaranteed to own the object 's monitor ? The reference says that when wait ( ) returns after a notify ( ) or notifyAll ( ) call , the thread waits until it acquires the object 's monitor . But what about the case when wait ( ) throws an exception ? <cod... | If wait ( ) throws an InterruptedException , does the thread wait until it acquires the object 's monitor ? |
Java : Consider the following codeWhen are these Strings created ? I assume the Strings will get created when an Exception occurs at run time . The string gets created at run time and is displayed . A peer of mine tells me that since these are constant Strings they will get created as soon as the Class loads . Is that ... | When are constant Strings created/destroyed ? |
Java : In java , I use the function all the time . Is there an equivalent function in python ? <code> variable = something == 1 ? 1 : 0 | Equivalent for ? in Java for Python ? |
Java : now i get some logs like below ( log-1 ) line 1010I think , the log should be like this ( log-2 ) I wannna know that why do i get log-1 , is it right ? If log-1 is right , then how can i write code to create an exception like that ? ps : I know that ClassA $ 1 is an anonymous class.ps : I get this log in a monke... | a ClassCastException about anonymous class ( java ) |
Java : I need to validate a user given String and validate that it is a valid Set , possibly a set that contains inner sets . Examples : This is the regex I am using ( broken up for readability ) : Currently the it accepts Sets with optional opening and closing brackets , but I need it to only accept if they are both t... | Mathematical Set Validation with regular-expression |
Java : I am in the following situation ... I am used to being able to check out a Subversion server subproject into JBoss as an exploded war : in my case , I call a directory Blah.war , put it in C : \jboss-6.1.0.Final\server\default\deploy\Blah.war , and JBoss picks it right up.I 'm having trouble doing this with Git ... | How to use a Git repository as an exploded war ? |
Java : I am hoping to get some help debugging this problem.If I send the following JSON to my backend it works correctly : However , if I now send the following : I get the above error . In my backend code I have the following : And the API method signature looks like this : I believe the problem I am having is that th... | The request sent by the client was syntactically incorrect Java ZonedDateTime backend |
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