graph - Android GraphView Gradel Error -

I need to make more graphs in my app and I think importing the library is (thought).

I just follow the rules and I add the compilation line of Gradle

This is the reason:.

  apply plugin: 'com.android.application' Android {compileSdkVersion 21 buildToolsVersion "21.1.1" Default Config {applicationId "com.btc.btcmobile" minSdkVersion 17 targetSdkVersion 21 Snskrnkod 1 Snskrnnam "1.0 "} buildTypes {release {minifyEnabled false proguardFiles getDefaultProguardFile ( 'proguard-android.txt'), 'proguard-rules.pro'}}} {dependency file compilation: ( 'dir:' libs', including: [* .jar ']) Compilation' com.android.support:appcompat-v7:21.0.3 'compile' com.jjoe64: article: 4.0 .0 '}  

After that, Copy-pasting the example on the site, but when I compile, Can see I:

Error: Execution

com.android.ide.common.internal.LoggedErrorException 'dexDebug: App': n failed to act. C: Failed to run command \ Users \ Valerio \ AppData \ Local \ Android \ Sdk2 \ build-tools \ 21.1.1 \ dx.bat --dex --no-optimize --output C: \ user \ valerio \ Desktop \ BtcMobile \ btcmobile \ app \ build \ intermediates \ dex \ debug --input -List = C: \ Users \ Valerio \ Desktop \ btcMobile \ btcmobile \ apps \ Construction \ intermediate \ tmp \ Dax \ debug \ inputList.txt error code : 2 Output: Unexpected top-level exception: com.android.dex.DexException: multiple deck files define Lcom / jjoe64 / graphview / BuildConfig; com.android.dx.merge.DexMerger.readSortableTypes (DexMerger.java:596) on com.android.dx.merge.DexMerger.getSortedTypes (DexMerger.java:554) on com.android.dx.merge.DexMerger.mergeClassDefs on com.android.dx.merge.DexMerger.merge (DexMerger.java:189) on com.android.dx.merge.DexMerger.mergeDexes (DexMerger.java:171) (DexMerger.java:535) on com.android. On dx.command.dexer.Main.mergeLibraryDexBuffers com.android.dx.command.dexer.Main.runMonoDex (Main.java:302) (Main.java:454) on com.android.dx.command.dexer.Main. Run on com.android.dx.command.dexer.Main.Main (main.java, 1414) com.android.dx.com (Main.Java Month 45). Main. MAIN (Main.Java 109) UNEXPECTED TOP-LEVEL EXCEPT:

How can I solve?

Thank you.