java 5 Vs 6

I am currently working on an application that was build using java 5.0. Recently I upgraded to java 6.0 and tried to build the application. The build fails. Is java 6.0 not backward compatible.

If i simply run my application on java 6.0 with out building (it has been build on java 5.0), will the application work fine.

Thanks in advance.

As far as I know Java is backwards compatible and you shouldn't experience troubles compiling. Might be, that code uses some features that were deprecated or something similar. Have you tryed using -source 1.5 switch when compiling? Maybe if you posted the errors you get when you compile we coud be of more help.

Since you are not preparing for SCJP, neither is this question about SCJP, I'll move it to a more appropriate forum...

Java 6 is supposed to be backward compatible with Java 5. However...

I have encountered a few Java 5 applications that will not compile correctly with Java 6. And I have encountered a Java 5 application, compiled with Java 5, that will not run correctly in Java 6. I guess there are flaws with the compatibility.

Henry

Runtime problems may occur, but building (compiling) should still work. Naresh, could you post your build error message(s)?

Sometimes code does change meaning with a new JDK; these are generally obscure cases, but they can be a pain in the class. There are some overloaded versions of StringBuffer::append() that were added in JDK 1.4 and JDK 1.5. Code that in JDK 1.3 might have invoked append(Object) will now invoke append(StringBuffer). If you compile that code with a 1.5 JDK, even if you use -source 1.3 -target 1.3, it won't execute on a 1.3 JRE because that method will be missing. Like I said, obscure, but a huge pain if you bump into it.

I know about some problems with some drivers too. I got a problem with postgres drivers when migrating my app.

You got any class version error after building(compiling).