UnsupportedClassVersionError - 1.7/1.5

Question

I created a Java application using Netbeans with JDK version as 1.7
Now how do I compile/run the same application on a different machine where JDK 1.5 is installed without making any changes to the code?

When I tried compiling I got an error saying JDK version mismatch.

Given below is the error:

java.lang.UnsupportedClassVersionError: MTPS : Unsupported major.minor version 51.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
    at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
Could not find the main class: MTPS.  Program will exit.

Answer 1

Changes from one java version to other have different functionality added. Like for example Enum functionality was added since java 1.5 if you try to compile it on 1.4 you get an error.

btw try to compile your app with JDK 1.5, and then if you succeed try to run it.