0. 配置标准

# 保持 Main 类内的 public 属性相同
-keep class xxx.Main {
    public *;
}
#    private void sensorRegisterListener(android.content.Context, android.hardware.SensorManager, android.hardware.Sensor);
# 对应 native
-keepclasseswithmembernames class xxx.Main {
    native <methods>;
}

# 保持对应的     -keepclassmembernames
-keepclassmembers class xxx.Main$* {
    public *;
}

-keep public class * extends android.app.Service

-keep public class xxx.BuildConfig

#引入依赖包rt.jar（jdk路径） ，， 需要配置
-libraryjars 'D:\ni\studio\jre\jre\lib\rt.jar'

#引入依赖包android.jar(android SDK 路径) ，， 在 gradle 中就已经配置了，这里不需要再次设置
#-libraryjars 'D:\sdk\platforms\android-28\android.jar'

#忽略警告    中间会后找不到 class 的警告，然后抛出错误，需添加这个
-ignorewarnings

#保证是独立的jar,没有任何项目引用,如果不写就会认为我们所有的代码是无用的,从而把所有的代码压缩掉,导出一个空的jar
-dontshrink

1. 输出混淆了的 jar 包

1. build.gradle 脚本

1. 生成 jar 包

def SDK_BASENAME = "raw_du";
def SDK_VERSION = "";
def sdkDestinationPath = "build";//生成jar存放目录

//打包release目录下的classes.jar(开启混淆后这个jar就是混淆的源码)----注意由于as版本原因有的在default目录
def releaseJar = file('build/intermediates/intermediate-jars/release/classes.jar')

//打包jar前先删除原先的jar
task deleteBuild(type: Delete) {
    delete sdkDestinationPath + SDK_BASENAME + SDK_VERSION + ".jar"
}

task makeJar(type: Jar) {
    from zipTree(releaseJar)//导出混淆的jar
    //from zipTree(debugJar)//导出未混淆的jar
    //from zipTree(thirdPartyJar)将第三方jar包打入jar包
    //from fileTree(dir: 'src/main', includes: ['assets/**'])//将assets目录打入jar包
    exclude('**/BuildConfig.class')//排除不必要的class文件
    baseName = SDK_BASENAME + SDK_VERSION
    destinationDir = file(sdkDestinationPath)
}

makeJar.dependsOn(deleteBuild, build)

上面这个就是生成了 jar 文件，对应 build/raw_du.jar 目录

2. 生成混淆了的 jar 包

task makeProguardJar(type: proguard.gradle.ProGuardTask, dependsOn: ['makeJar']) {
    // 未混淆的jar路径
    injars 'build/raw_du.jar'
    // 混淆后的jar输出路径
    outjars 'build/proGuard_du.jar'
    // 混淆协议
    configuration 'proguard-rules.pro'
}

直接生成了 build/proGuard_du.jar 混淆后的文件

2. 生成混淆了的 jar 包

task makePPPJar(type: proguard.gradle.ProGuardTask, dependsOn: "build") {
    //删除已有的jar包
    delete 'build/proGuard_du.jar'
    // 未混淆的jar路径
    injars 'build/intermediates/intermediate-jars/release/classes.jar'
    // 混淆后的jar输出路径
    outjars 'build/proGuard_du.jar'
    // 混淆协议
    configuration 'proguard-rules.pro'
}

这个 gradle 命令，对应的混淆配置是 proguard-rules.pro

模版如下

#表示混淆时不使用大小写混合类名
-dontusemixedcaseclassnames
#表示不跳过library中的非public的类
-dontskipnonpubliclibraryclasses
#打印混淆的详细信息
-verbose

# Optimization is turned off by default. Dex does not like code run
# through the ProGuard optimize and preverify steps (and performs some
# of these optimizations on its own).
-dontoptimize
##表示不进行校验,这个校验作用 在java平台上的
-dontpreverify
# Note that if you want to enable optimization, you cannot just
# include optimization flags in your own project configuration file;
# instead you will need to point to the
# "proguard-android-optimize.txt" file instead of this one from your
# project.properties file.

-keepattributes *Annotation*
-keep public class com.google.vending.licensing.ILicensingService
-keep public class com.android.vending.licensing.ILicensingService

# For native methods, see http://proguard.sourceforge.net/manual/examples.html#native
-keepclasseswithmembernames class * {
    native <methods>;
}

# keep setters in Views so that animations can still work.
# see http://proguard.sourceforge.net/manual/examples.html#beans
-keepclassmembers public class * extends android.view.View {
   void set*(***);
   *** get*();
}

# We want to keep methods in Activity that could be used in the XML attribute onClick
-keepclassmembers class * extends android.app.Activity {
   public void *(android.view.View);
}

# For enumeration classes, see http://proguard.sourceforge.net/manual/examples.html#enumerations
-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keepclassmembers class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator CREATOR;
}

-keepclassmembers class **.R$* {
    public static <fields>;
}

# 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.**

# Understand the @Keep support annotation.
-keep class android.support.annotation.Keep

-keep @android.support.annotation.Keep class * {*;}

-keepclasseswithmembers class * {
    @android.support.annotation.Keep <methods>;
}

-keepclasseswithmembers class * {
    @android.support.annotation.Keep <fields>;
}

-keepclasseswithmembers class * {
    @android.support.annotation.Keep <init>(...);
}

# 保持 Main 类内的 public 属性相同
-keep class ***.Main {
    public *;
}
# 对应 native
-keepclasseswithmembernames class ***.Main {
    native <methods>;
}

-keep public class * extends android.app.Service

# 如果有这个类，就保持
-keep class com.kok.http.BuildConfig{
public *;
}

#引入依赖包rt.jar（jdk路径） ，， 需要配置
-libraryjars 'D:\ni\studio\jre\jre\lib\rt.jar'

#引入依赖包android.jar(android SDK路径) ，， 在 gradle 中就已经配置了，这里不需要再次设置
#-libraryjars 'D:\sdk\platforms\android-28\android.jar'

#忽略警告    中间会后找不到 class 的警告，然后抛出错误，需添加这个
-ignorewarnings

#保证是独立的jar,没有任何项目引用,如果不写就会认为我们所有的代码是无用的,从而把所有的代码压缩掉,导出一个空的jar
-dontshrink

2. 操作

双击执行 gradle 栏目的 core/Tasks/other/makeProguardJar 条目

3. 文档较多，这里不再