1.Create the batch file
.bat file contents like
[ ] cd\
[ ]cd <path to the .exe file of your Java program>
[ ] <.exe file name>
2. In SilkTest you can call this with Sys_Execute("The batch file name along with its path")
I was using Sys_Execute only, but the .bat file was not being run. After debugging through Silk identified that the Java program is not finding the required classpaths. Modified the .bat file to include jre\lib\rt.jar and the java program class.
Also noted that, if the classpath is too big Sys_execute trncates it and wont execute the Java program.