Java Compilation Error

public class SimpleJava {
  
   public void showMessage() {
      System.out.println("Here we are");
   }
}   

Ran into this small little problem when compiling java to use in an Oracle procedure.

ORA-29516: Aurora assertion failure: Assertion failure at eox.c:359 Uncaught exception System error: java/lang/UnsupportedClassVersionError

I could understand that I had somehow compiled the class using an incorrect version but seeing as I had done this from the server I thought I would have been OK. A bit of digging and I came up with the following:

Find the version the class was actually compiled in:

javap -verbose SimpleJava

This gave the following output along with some other info:

public class SimpleJava extends java.lang.Object
SourceFile: "SimpleJava.java"
minor version: 0
major version: 50

Table of versions:

major  minor Java platform version 

45       3           1.0

45       3           1.1

46       0           1.2

47       0           1.3

48       0           1.4

49       0           1.5

50       0           1.6

Using the above table I could see that I had compiled it with 1.6. But how had this happened as I had used the server to compile the java file? Well I had missed a crutial point, the database and application aren't on the same server and in this case the database server is running an eariler Java version. I checked it using this:

java -version

Output: 

java version "1.4.2"

So my problem was that I was compiling on the Application server using a higher version than the one on the database. Solution:

javac -source 1.4  -target 1.4 SimpleJava.java

Using just the -target 1.4 did not solve the problem completely.

Source

Thiam Teck