I have a 3rd party JAR file that is compiled using Java 1.4. Is there a tool that can make the jar file compatible with Java 1.6? (Something like 'retrotranslator' but what does the reverse of it).
I tried decompiling the class files and re compile them in 1.6 but it fails.
Here is the issue:
My project uses 'rsadapter.jar' for was 5.1 and I had my project setup in Eclipse 2.0 + JDK 1.4 and it used to work fine. Now, I have migrated to Java 1.6 and Eclipse Ganymede (as per the requirements) and the same project (exactly same setup) started complaining about the missing class files in the 'rsadapter.jar'. I put the JAR in classpath explicitly too but it still could not load the classes. Then I changed the Java Compiler version to 1.4 and it started working.
Regards,
- Ashish
Classes compiled by JDK 1.4 should be usable in a Java 6 runtime as-is. If you have actually encountered a problem, please describe it.
Update: I can only reproduce this with types in the "default" package (that is, not in a package). Are the classes you are trying to use in the default package? Also, this happens to me regardless of the JDK version used to compile.
Update: Okay, after a little research, I realized that you can never reference a type in the unnamed package from a named package. Makes sense, but definitely not what you are running into.
I can compile code under JDK 1.4.2_19 and utilize it just fine in a Java 6 Eclipse project. I think that this problem is something specific to your environment. In this situation, I would backup Eclipse and recreate everything (JDK installation, workspace, projects) from scratch, to see if I could clear it up.