Android Error because of library files are in application path + module path

Error:Execution failed for task ':app:dexDebug'.

> com.android.ide.common.internal.LoggedErrorException: Failed to run command:

  /Users/retheesh.r/Library/Android/sdk/build-tools/21.1.2/dx --dex --no-optimize --output /Users/retheesh.r/Desktop/RR/per/Projects/EyeOMe/app/build/intermediates/dex/debug --input-list=/Users/retheesh.r/Desktop/RR/per/Projects/EyeOMe/app/build/intermediates/tmp/dex/debug/inputList.txt

  Error Code:

  2

  Output:

  UNEXPECTED TOP-LEVEL EXCEPTION:

  com.android.dex.DexException: Multiple dex files define Lde/mindpipe/android/logging/log4j/LogCatAppender;

  at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:596)

  at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:554)

  at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:535)

  at com.android.dx.merge.DexMerger.mergeDexes(DexMerger.java:171)

  at com.android.dx.merge.DexMerger.merge(DexMerger.java:189)

  at com.android.dx.command.dexer.Main.mergeLibraryDexBuffers(Main.java:454)

  at com.android.dx.command.dexer.Main.runMonoDex(Main.java:303)

  at com.android.dx.command.dexer.Main.run(Main.java:246)

  at com.android.dx.command.dexer.Main.main(Main.java:215)

  at com.android.dx.command.Main.main(Main.java:106)

This issue was because the Log4J jar file was included in the app jar directory and as well inside the module lib folder.