D:\Program Files\Java\jdk1.7.0_17\bin\java.exe'' finished with non-zero exit value 2

Error:Execution failed for task ':app:transformClassesWithDexForDebug'.
> com.android.build.api.transform.TransformException: com.android.ide.common.process.ProcessException: org.gradle.process.internal.ExecException: Process 'command 'D:\Program Files\Java\jdk1.7.0_17\bin\java.exe'' finished with non-zero exit value 2
这咋办？