Java
Java (not to be confused with JavaScript or JScript or JS) is a general-purpose object-oriented programming language designed to be used in conjunction with the Java Virtual Machine (JVM). "Java platform" is the name for a computing system that has installed tools for developing and running Java programs. Use this tag for questions referring to the Java programming language or Java platform tools.
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How to fix java.lang.UnsupportedClassVersionError: Unsupported major.minor version
I am trying to use Notepad++ as my all-in-one tool edit, run, compile, etc. I have JRE installed, and I have
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Difference between StringBuilder and StringBuffer
What is the main difference between StringBuffer and StringBuilder? Is there any performance issues when decid
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Why use getters and setters/accessors?
What's the advantage of using getters and setters - that only get and set - instead of simply using publi
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How can I avoid Java code in JSP files, using JSP 2?
I'm new to Java EE and I know that something like the following three lines <%= x+1 %> <%= reque
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Sort a Map<Key, Value> by values
I am relatively new to Java, and often find that I need to sort a Map<Key, Value> on the values. Since
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How to split a string in Java
I have a string, "004-034556", that I want to split into two strings: string1="004"; string2="034556"; That
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Why does this code using random strings print "hello world"?
The following print statement would print "hello world". Could anyone explain this? System.out.println(random
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How to generate a random alpha-numeric string
I've been looking for a simple Java algorithm to generate a pseudo-random alpha-numeric string. In my si
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Does Java support default parameter values?
I came across some Java code that had the following structure: public MyParameterizedFunction(String param1,
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Java inner class and static nested class
What is the main difference between an inner class and a static nested class in Java? Does design / implementa
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Comparing Java enum members: == or equals()?
I know that Java enums are compiled to classes with private constructors and a bunch of public static members.
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How do I break out of nested loops in Java?
I've got a nested loop construct like this: for (Type type : types) { for (Type t : types2) {
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How to use java.net.URLConnection to fire and handle HTTP requests
Use of java.net.URLConnection is asked about pretty often here, and the Oracle tutorial is too concise about i
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What is a JavaBean exactly?
I understood, I think, that a "Bean" is a Java class with properties and getters/setters. As much as I underst
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How do you assert that a certain exception is thrown in JUnit 4 tests?
How can I use JUnit4 idiomatically to test that some code throws an exception? While I can certainly do somet
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What's the simplest way to print a Java array?
In Java, arrays don't override toString(), so if you try to print one directly, you get the className + &
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How to get an enum value from a string value in Java
Say I have an enum which is just public enum Blah { A, B, C, D } and I would like to find the enum value
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"implements Runnable" vs "extends Thread" in Java
From what time I've spent with threads in Java, I've found these two ways to write threads: With imp
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What's the difference between @Component, @Repository & @Service annotations in Spring?
Can @Component, @Repository and @Service annotations be used interchangeably in Spring or do they provide any
