看大佬造轮子：如何写一个Mess 混淆Activity、View

buildTypes {
    release {
        minifyEnabled true
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}

# The support library contains references to newer platform versions.
# Don't warn about those in case this app is linking against an older
# platform version.  We know about them, and they are safe.
-dontwarn android.support.**


#保留R下面的资源
-keep class **.R$* {*;}

#保留本地native方法不被混淆
-keepclasseswithmembernames class * {
    native <methods>;
}

#保留在Activity中的方法参数是view的方法，
#这样以来我们在layout中写的onClick就不会被影响
-keepclassmembers class * extends android.app.Activity{
    public void *(android.view.View);
}

#保留枚举类不被混淆
-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

#保留我们自定义控件（继承自View）不被混淆
-keep public class * extends android.view.View{
    *** get*();
    void set*(***);
    public <init>(android.content.Context);
    public <init>(android.content.Context, android.util.AttributeSet);
    public <init>(android.content.Context, android.util.AttributeSet, int);
}

#保留Parcelable序列化类不被混淆
-keep class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator *;
}

#保留Serializable序列化的类不被混淆
-keepclassmembers class * implements java.io.Serializable {
    static final long serialVersionUID;
    private static final java.io.ObjectStreamField[] serialPersistentFields;
    private void writeObject(java.io.ObjectOutputStream);
    private void readObject(java.io.ObjectInputStream);
    java.lang.Object writeReplace();
    java.lang.Object readResolve();
}

if (config.isMinifyEnabled()) {//如果开启混淆 上文gradle中 minifyEnabled 的配置

    File sdkDir = scope.getGlobalScope().getSdkHandler().getAndCheckSdkFolder();
    checkNotNull(sdkDir);
    //默认的混淆配置和项目的混淆配置文件 即前文的proguard-android.txt 和 proguard-rules.pro
    File defaultProguardFile = ProguardFiles.getDefaultProguardFile(
            TaskManager.DEFAULT_PROGUARD_CONFIG_FILE, project);

    Set<File> proguardFiles = config.getProguardFiles(true /*includeLibs*/,
            ImmutableList.of(defaultProguardFile));
    File proguardResFile = scope.getProcessAndroidResourcesProguardOutputFile();
    proguardFiles.add(proguardResFile);
    // for tested app, we only care about their aapt config since the base
    // configs are the same files anyway.
    
    if (scope.getTestedVariantData() != null) {
    	//和资源相关的混淆信息文件
        proguardResFile = scope.getTestedVariantData().getScope()
                .getProcessAndroidResourcesProguardOutputFile();
        proguardFiles.add(proguardResFile);
    }
    options.setProguardFiles(proguardFiles);
    options.setMappingFile(new File(scope.getProguardOutputFolder(), "mapping.txt"));
}

@Override
  @NonNull
  public File getProcessAndroidResourcesProguardOutputFile() {
      return new File(globalScope.getIntermediatesDir(),
              "/proguard-rules/" + getVariantConfiguration().getDirName() + "/aapt_rules.txt");
  }

variant.outputs.each { BaseVariantOutput output ->

	//Hook ProcessAndroidResources Task
    String taskName = "transformClassesAndResourcesWithProguardFor${variant.name.capitalize()}"
    def proguardTask = project.tasks.findByName(taskName)
    if (!proguardTask) {
        return
    }

    boolean hasProcessResourcesExecuted = false
    output.processResources.doLast {
        if (hasProcessResourcesExecuted) {
            return
        }
        hasProcessResourcesExecuted = true
        //删除 aapt_rules.txt保证 activity、view被混淆 
        def rulesPath = "${project.buildDir.absolutePath}/intermediates/proguard-rules/${variant.dirName}/aapt_rules.txt"
        File aaptRules = new File(rulesPath)
        aaptRules.delete()
        aaptRules.createNewFile()
        aaptRules << ""
    }

    proguardTask.doFirst {
    	//隐藏依赖库的混淆配置
        println "start ignore proguard components"
        ext.ignoreProguardComponents.each { String component ->
            Util.hideProguardTxt(project, component)
        }
    }

    proguardTask.doLast {
    	// 读取maping.txt 、修改替换xml的数据
    	// 详情看RewriteComponentTask的实现，主要是文件的读取修改逻辑
        println "proguard finish, ready to execute rewrite"
        RewriteComponentTask rewriteTask = project.tasks.create(name: "rewriteComponentFor${variant.name.capitalize()}",
                type: RewriteComponentTask
        ) {
            apkVariant = variant
            variantOutput = output
        }
        rewriteTask.execute()
    }

    proguardTask.doLast {
    	//恢复依赖库混淆配置
        ext.ignoreProguardComponents.each { String component ->
            Util.recoverProguardTxt(project, component)
        }
    }
}