为什么只在发布版本中包含依赖关系？

Question

从一个全新的Android Studio 2.2.3项目开始,接受除了选择退出AppCompat之外的所有默认值,我添加了两个依赖项app/build.gradle:

apply plugin: 'com.android.application'

android {
  compileSdkVersion 25
  buildToolsVersion "25.0.0"
  defaultConfig {
    applicationId "com.commonsware.myapplication"
    minSdkVersion 15
    targetSdkVersion 25
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
  }
  buildTypes {
    release {
      minifyEnabled false
      proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
  }
}

dependencies {
  compile 'com.google.code.gson:gson:2.4'
  compile 'com.squareup.okhttp3:okhttp:3.5.0'
  androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
    exclude group: 'com.android.support', module: 'support-annotations'
  })
  testCompile 'junit:junit:4.12'
}

即使我从Gson或OkHttp引用类,编译时也没有问题.但是,我从Android Studio运行应用程序并获得可怕的NoClassDefFoundError:

12-16 10:48:52.175 15687-15687/com.commonsware.myapplication E/AndroidRuntime: FATAL EXCEPTION: main
   Process: com.commonsware.myapplication, PID: 15687
   java.lang.NoClassDefFoundError: Failed resolution of: Lcom/google/gson/GsonBuilder;
       at com.commonsware.myapplication.MainActivity.onCreate(MainActivity.java:13)
       at android.app.Activity.performCreate(Activity.java:6251)
       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)
       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
       at android.app.ActivityThread.-wrap11(ActivityThread.java)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
       at android.os.Handler.dispatchMessage(Handler.java:102)
       at android.os.Looper.loop(Looper.java:148)
       at android.app.ActivityThread.main(ActivityThread.java:5417)
       at java.lang.reflect.Method.invoke(Native Method)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
    Caused by: java.lang.ClassNotFoundException: Didn't find class "com.google.gson.GsonBuilder" on path: DexPathList[[zip file "/data/app/com.commonsware.myapplication-1/base.apk"],nativeLibraryDirectories=[/data/app/com.commonsware.myapplication-1/lib/arm, /vendor/lib, /system/lib]]
       at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
       at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
       at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
       at com.commonsware.myapplication.MainActivity.onCreate(MainActivity.java:13) 
       at android.app.Activity.performCreate(Activity.java:6251) 
       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107) 
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369) 
       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
       at android.app.ActivityThread.-wrap11(ActivityThread.java) 
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
       at android.os.Handler.dispatchMessage(Handler.java:102) 
       at android.os.Looper.loop(Looper.java:148) 
       at android.app.ActivityThread.main(ActivityThread.java:5417) 
       at java.lang.reflect.Method.invoke(Native Method) 
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
    Suppressed: java.lang.ClassNotFoundException: com.google.gson.GsonBuilder
       at java.lang.Class.classForName(Native Method)
       at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
       at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
       at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
          ... 14 more
    Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack trace available

如果我使用Android Studio的APK分析器进行分析app-debug.apk,我发现APK中不包含任何来自我的两个依赖项的内容,除了引用GsonBuilder:

我从命令行build(gradle clean assembleDebug)获得相同的结果.

但是,release构建显示包含依赖项的APK:

如果我切换到这些工件(com.google.code.gson:gson:2.3和com.squareup.okhttp3:okhttp:3.2.0)的旧版本,它们会在debug构建中正确显示.问题是每个工件,所以如果我包含较旧的Gson和较新的OkHttp,我的debug构建包含不是OkHttp的Gson类.

因此,回顾一下:对于这些特定工​​件的这些特定版本,对于debug构建,工件的内容不会添加到我的APK中.

问题是:为什么？

Answer 1

问题是新构建缓存中出现某种损坏。清除构建缓存可以解决问题。

我提出了一个关于此问题的问题，但由于我没有可重现的损坏构建缓存的场景，因此该问题的实用性可能有限。