jar包引用时，小哥哥犯的错

我刚开始引用jar包的时候，用的是本地引用，

 修改宿主apk的build.gradle的dependencies：
repositories {
flatDir {
dirs 'libs'
}
}
dependencies {
compile(name:'cnadsdk', ext:'jar')
}

然后我一build demo 看到报一大堆类似先面的错误我慌了

AGPBI: {"kind":"error","text":"Program type already present: com.cc.c.e.Base64","sources":[{}],"tool":"D8"}
:app:transformDexArchiveWithExternalLibsDexMergerForDebug FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:transformDexArchiveWithExternalLibsDexMergerForDebug'.
> com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives: D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\0.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\1.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\2.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\3.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\4.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\5.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\6.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\7.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\8.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\9.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\10.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\11.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\12.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\13.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\14.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\15.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\16.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\17.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\18.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\19.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\20.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\21.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\22.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\23.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\24.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\25.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\26.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\27.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\28.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\29.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\30.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\31.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\32.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\33.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\34.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\35.jar, D:\work\leshice\app\build\intermediates\transforms\dexBuilder\debug\36.jar
  Learn how to resolve the issue at https://developer.android.com/studio/build/dependencies#duplicate_classes.
  Program type already present: com.cc.c.e.Base64

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 6s

后来我翻了各种资料也没找出，主要是问题都不沾边
其实也是因为操作看不懂等等 ；
但是我翻了十篇博客后才意识到了一点，可能是我的一些依赖重复 ，
或者两个相同类进行重复引用，当然这个是我看博文神么额，
一般都是这种类似说法、。
后来，我徐哥发现
我们多引用了个
// implementation fileTree(include: [’*.jar’], dir: ‘libs’)
然后build 了一下项目，不报红了，心里也是。。。。了；‘

后来徐哥还说

// 可以一条依赖引入libs下所有的jar
implementation fileTree(dir: 'libs', include: ['*.jar'])

// 也可以指定依赖某一个或几个jar
implementation files('libs/dict-v120.jar', 'libs/download-v151.jar')’