!!Java Versions We compiled most of the programs with 1.5.0_11 and have tested most with 1.7.0. *Many programs will NOT work with 1.4 or earlier. *Very few will work with 1.3. If you get an error similar to: {{{java.lang.UnsupportedClassVersionError: .... (Unsupported major.minor version 49.0)}}} You will need to be sure you are using at least Java 1.5. You can retrieve the JVM Version of java you are running by typing: {{{java -version}}} Java bytecode version represents the format used for the class files. The bytecode version allow JVMs to verify that the class file is loadable. Every JVM has a maximum version it can load, and JVMs will reject class files with later versions. The "java.lang.UnsupportedClassVersionError" is thrown when the JVM is attempting to load a class file format (bytecode version) that the JVM is unable to support. We found a good list for checking [byteCode Versions|Wikipedia:Java_class_file|target='_blank'] The following table gives the bytecode versions that will run on a particular JVM version, as listed by Sun or determined by experiment. ||Bytecode Version||JVM Version||Source |45.0 - 45.3|1.0.2|Sun |45.0 - 45.65535|1.1.*|Sun |45.0 - 46.0|1.2|Sun; experiment suggests that some 1.2 JVMs also support 46.3 |45.0 - 47.0|1.3|Experiment |45.0 - 48.0|1.4|Experiment |45.0 - 49.0|5 (1.5)|Experiment The system property "java.class.version" determines the Maximum version the JVM supports. The following table shows the "java.class.version" for each version of the JVM: * 1.1 = <45.3> * 1.2 = <46.0> * 1.3 = <47.0> * 1.4 = <48.0> * 1.5 = <49.0> * 1.6 = <50.0> * 1.7 = <51.0> * 1.8 = <52.0> So if a class file has a bytecode format of 49.0 and it is attempted to run on a 1.4 JVM, you will get a error like: {{{java.lang.UnsupportedClassVersionError: .... (Unsupported major.minor version 49.0)}}} Which implies that the JVM is not able to support a bytecode format of 49.0. !! More Information There might be more information for this subject on one of the following: [{ReferringPagesPlugin before='*' after='\n' }]