javac

When using the same JDK (i.e. the same javac executable), are the generated class files always identical? Can there be a difference depending on the operating system or hardware ? Except of the JDK version, could there be any other factors resulting in differences? Are there any compiler options to avoid differences? Is a difference only possibly in theory or does Oracle's javac actually produce different class files for the same input and compiler options? Update 1 I'm interested in the generation , i.e. compiler output, not whether a class file can be run on various platforms. Update 2 By

For a challenge, a fellow code golfer wrote the following code : import java.util.*; public class Main { public static void main(String[] args) { int size = 3; String[] array = new String[size]; Arrays.fill(array, ""); for(int i = 0; i <= 100; ) { array[i++%size] += i + " "; } for(String element: array) { System.out.println(element); } } } When running this code in Java 8, we get the following result: 1 4 7 10 13 16 19 22 25 28 31 34 37 40 43 46 49 52 55 58 61 64 67 70 73 76 79 82 85 88 91 94 97 100 2 5 8 11 14 17 20 23 26 29 32 35 38 41 44 47 50 53 56 59 62 65 68 71 74 77 80 83 86 89 92 95 98

I have my java source files in src/net/... folders and .jar files in lib folder. How to compile and run this files with command line without writing build script ? Lets say you have your code files in [someDirectory] | +-[lib] | | | +-someLib.jar | +-someOtherLib.jar | +-... | +--[src] | +-[net] | +-[name] | +-[one] | +-[two] | +-[main] | +-Main.java <- code you want to compile and execute then if your console is in someDirectory> you can compile it with someDirectory>javac -cp "lib\*" src\net\name\one\two\main\Main.java but this will produce Main.class file in same directory as Main.java so

I'm trying to run 'javac' tool on a compiled .class file in Eclipse. I open External Tools Configuration them fill the filds: Location: C:\Program Files\Java\jdk1.6.0_25\bin\javac.exe Working directory: ${workspace_loc:/Main/bin} Arguments: ? I want to ask you what must I write in the Arguments field, and am I fill* Location * and Working directory: fields right ? Launching the javac compiler from within Eclipse can be a very useful feature in some cases (e.g. for testing purposes, to compare the javac output with the output of the Eclipse compiler, to recompile individual class files with

Consider the following code: public class Main { public static class NormalClass { public Class<Integer> method() { return Integer.class; } } public static class GenericClass<T> { public Class<Integer> method() { return Integer.class; } } public static void main(String... args) { NormalClass safeInstance = new NormalClass(); Class<Integer> safeValue = safeInstance.method(); GenericClass unsafeInstance = new GenericClass(); Class<Integer> unsafeValue = unsafeInstance.method(); } } If I compile it with: $ javac -Xlint:unchecked Main.java It returns: Main.java:16: warning: [unchecked] unchecked

NOTE: Please do not comment on all the perils of cross-compiling. Thank you. I have a situation where we need to have Java 6 source compiled for a Java 5 JVM (to be sure that JAX-WS usage is correct). Previously we have done this with ant ant script (which apparently can), but after migrating to Maven we have found that it ends up with javac complaining: $ javac -source 1.6 -target 1.5 javac: source release 1.6 requires target release 1.6 Is there any Java distribution for Linux (Ubuntu 11.10, x86) where the javac can do this? EDIT: It appears not, as the limitation is in javac which is the

This question already has an answer here: How come invoking a (static) method on a null reference doesn't throw NullPointerException? 5 answers I was pointing some tricks and came across this. In following code: public class TestClass1 { static int a = 10; public static void main(String ar[]){ TestClass1 t1 = null ; System.out.println(t1.a); // At this line } } t1 object is null . Why this code is not throwing NullPointerException ? I know this is not proper way to access static variables but question is about NullPointerException . To add some additional info to the current answers, if you