liaoxing - 2004-06-02

    Hello,I am a graduate student from china. I am trying to extend the 'JRefactory' software.I
have downloaded jrefactory-2.9.19-full and try to build the JRefactory source code in JBuilder9
IDE ,I find the exception as follows:

    cannot access edu.umd.cs.findbugs.ba.SourceFile,
    bad class file: H:\RefactoryProForJBuider9\classes\edu\umd\cs\findbugs\ba\SourceFile.class,
    class file has wrong version 49.0, should be 48.0,
    Please remove or make sure it appears in the correct subdirectory of the classpath. at line 49 (49:31)

   I am puzzled with this problem for many days .Can you help me ?,meamwhile I expect
your guidance
    thanks  .