[Error] java.lang.OutOfMemoryError

[Ycsm2015]

   [dx] UNEXPECTED TOP-LEVEL ERROR:
   [dx] java.lang.OutOfMemoryError: GC overhead limit exceeded

BUILD FAILED
D:\workspace\ViewTest\custom_rules.xml:26: null returned: 3

Total time: 6 minutes 31 seconds

D:\workspace\ViewTest>

Sometimes the Error also went like: [dx] java.lang.OutOfMemoryError: java heap space

What's the problem about? I'need help..