从 Gradle 依赖项中排除.class文件

我正在尝试使用gradle将 https://github.com/Kickflip/kickflip-android-sdk 导入到我的Android版本中，我得到了：

意想不到的顶级异常：com.android.dex.DexException：多个dex文件定义Lorg/apache/commons/codec/binary/Base64;

Commons.codec是我项目的一个依赖项，但不是直接的kick-flip项目，我认为它来自其中包含的一个jars。如果我打开Kickflip的类，我可以看到.class文件.jar。

如何排除 Base64.class 从 kickflip 导入到最终版本中？我已经考虑过使用ziptree来排除某些东西，但无法让任何东西发挥作用。

谢谢

我的 build.gradle 是：

apply plugin: 'android'

android {
    compileSdkVersion 19
    buildToolsVersion "19.0.3"

    defaultConfig {
        minSdkVersion 10
        targetSdkVersion 19
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            runProguard false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
        }
    }

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_7
        targetCompatibility JavaVersion.VERSION_1_7
    }

    packagingOptions {
        exclude 'META-INF/DEPENDENCIES.txt'
        exclude 'META-INF/LICENSE.txt'
        exclude 'META-INF/NOTICE.txt'
        exclude 'META-INF/NOTICE'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/DEPENDENCIES'
        exclude 'META-INF/notice.txt'
        exclude 'META-INF/license.txt'
        exclude 'META-INF/dependencies.txt'
        exclude 'META-INF/LGPL2.1'
        exclude 'META-INF/ASL2.0'
    }

    android.applicationVariants.all{ variant ->
        // This is an annoying hack to get around the fact that the Gradle plugin does not support
        // having libraries with different minSdkVersions. Play Services has a min version of 9 (Gingerbread)
        // but Android Maps Utils supports 8 (Froyo) still
        variant.processManifest.doFirst {
        File manifestFile = file("${buildDir}/exploded-aar/io.kickflip/sdk/0.9.9/AndroidManifest.xml")
            if (manifestFile.exists()) {
                println("Replacing minSdkVersion in Android Maps Utils")
                String content = manifestFile.getText('UTF-8')
                content = content.replaceAll(/minSdkVersion="18"/, 'minSdkVersion=\"10\"')
                manifestFile.write(content, 'UTF-8')
                println(content)
            }
        }
    }
}

dependencies {
    compile 'com.android.support:support-v4:19.1.0'
    compile 'io.kickflip:sdk:0.9.9'
    compile fileTree(dir: 'libs', include: '*.jar')
    compile project(':libs:typeface-textview:library')
    compile project(':libs:gpuimage')
    compile 'com.google.android.gms:play-services:4.3.23'
    compile 'com.nineoldandroids:library:2.4.0'
    compile 'com.koushikdutta.urlimageviewhelper:urlimageviewhelper:1.0.4'
    compile ('fr.avianey:facebook-android-api:3.14.0') {
      exclude module: 'support-v4'
    }
    compile 'com.github.japgolly.android:svg-android:2.0.1'
    compile 'org.scribe:scribe:1.3.5'
    compile 'commons-codec:commons-codec:1.8'
}