问Android Studio: Gradle - build失败--任务':dexDebug‘执行失败

EN

Gradle: Execution failed for task ':vertretungsplan:dexDebug'.
> Failed to run command:
    P:\Android-Studio\sdk\build-tools\18.0.1\dx.bat --dex --output P:\Projekte\VertretungsplanProject\vertretungsplan\build\libs\vertretungsplan-debug.dex P:\Projekte\VertretungsplanProject\vertretungsplan\build\classes\debug P:\Projekte\VertretungsplanProject\vertretungsplan\build\dependency-cache\debug P:\Android-Studio\sdk\extras\android\m2repository\com\android\support\support-v4\18.0.0\support-v4-18.0.0.jar P:\Projekte\VertretungsplanProject\vertretungsplan\libs\commons-io-2.4.jar P:\Projekte\VertretungsplanProject\vertretungsplan\build\exploded-bundles\VertretungsplanProjectLibrariesActionbarsherlockUnspecified.aar\classes.jar
Error Code:
    2
Output:
    trouble processing:
    bad class file magic (cafebabe) or version (0033.0000)
    ...while parsing de/MayerhoferSimon/Vertretungsplan/LoginActivity$2.class
    ...while processing de/MayerhoferSimon/Vertretungsplan/LoginActivity$2.class
    trouble processing:
    bad class file magic (cafebabe) or version (0033.0000)
    ...while parsing de/MayerhoferSimon/Vertretungsplan/MainActivity$1.class
    ...while processing de/MayerhoferSimon/Vertretungsplan/MainActivity$1.class
    trouble processing:
    bad class file magic (cafebabe) or version (0033.0000)
    ...while parsing de/MayerhoferSimon/Vertretungsplan/YQL/YqlVplanParser.class
    ...while processing de/MayerhoferSimon/Vertretungsplan/YQL/YqlVplanParser.class
    3 warnings
    UNEXPECTED TOP-LEVEL EXCEPTION:
    com.android.dx.util.DexException: Multiple dex files define Landroid/support/v4/accessibilityservice/AccessibilityServiceInfoCompat$AccessibilityServiceInfoVersionImpl;
        at com.android.dx.merge.DexMerger.readSortableTypes(DexMerger.java:592)
        at com.android.dx.merge.DexMerger.getSortedTypes(DexMerger.java:550)
        at com.android.dx.merge.DexMerger.mergeClassDefs(DexMerger.java:531)
        at com.android.dx.merge.DexMerger.mergeDexBuffers(DexMerger.java:168)
        at com.android.dx.merge.DexMerger.merge(DexMerger.java:186)
        at com.android.dx.command.dexer.Main.mergeLibraryDexBuffers(Main.java:300)
        at com.android.dx.command.dexer.Main.run(Main.java:232)
        at com.android.dx.command.dexer.Main.main(Main.java:174)
        at com.android.dx.command.Main.main(Main.java:91)

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.5.+'
    }
}
apply plugin: 'android-library'

dependencies {
    compile 'com.android.support:support-v4:18.0.0'
}

android {
    compileSdkVersion 18
    buildToolsVersion "18.0.1"

    defaultConfig {
        minSdkVersion 8
        targetSdkVersion 11
    }

    sourceSets {
        main {
            manifest.srcFile 'AndroidManifest.xml'
            java.srcDirs = ['src']
            resources.srcDirs = ['src']
            res.srcDirs = ['res']
        }
    }
}

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.5.+'
    }
}
apply plugin: 'android'

dependencies {
    compile files('libs/commons-io-2.4.jar')
    compile project(':libraries:actionbarsherlock')
}

android {
    compileSdkVersion 18
    buildToolsVersion "18.0.1"

    defaultConfig {
        minSdkVersion 8
        targetSdkVersion 11
    }
}

include ':vertretungsplan', ':libraries:actionbarsherlock'