Java exception unknown source

Sometimes when debugging application we may run into this exception - Java Exception unknown source.
The possible reason could be when compiling the application, javac ant tasks omits debug option by defaut. So we will have to explicity set debug flag to true. See the javac ant task documentation for more info. You can mention some thing like below:
<target name="compile">
  <javac srcdir="${src.dir}" destdir="{dest.dir}." debug="on" debuglevel="lines,vars,source" />
Hope this helps.


  1. Hi Can you help me with few question
    Q1 what is permsize and maxpermsize, what is its use.
    Q2 if we set xms and xmx equals how garbage collection happen
    Q3. if in datasource configuration if we set Initial Capacity and Maximum Capacity same then what is the use of Capacity Increment

    You can mail ur answers at
    Thank You

  2. Thanks man that really helped me.