Apk文件被反編譯出來能被獲取到里面的代碼。對于這種情況捂齐，我們可以對項目代碼進行混淆蛮放，隨機生成難理解的類名，方法名奠宜，讓代碼難以閱讀包颁，加大功能被盜取的難度⊙拐妫混淆可以起到壓縮Apk娩嚼，混淆文件，預檢滴肿，優(yōu)化的作用岳悟。

1. 使用方式，在gradle文件中設置minifyEnabled為true即可開啟混淆

    buildTypes {
        release {
            minifyEnabled ture  //是否開啟代碼混淆
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }

混淆內容在proguard-android.txt或者proguard-rules.pro文件中寫泼差。

2. 混淆設置參數(shù)

-optimizationpasses 4 代碼混淆的壓縮比例贵少，值介于0-7

-dontusemixedcaseclassnames 混淆后類型都為小寫

-dontskipnonpubliclibraryclasses 不去忽略非公共的庫類

-dontoptimize 不優(yōu)化輸入的類文件

-dontpreverify 不做預校驗的操作

-ignorewarnings 忽略警告

-verbose 混淆時是否記錄日志

-keepattributes Annotation 保護注解

-printmapping proguardMapping.txt 生成原類名和混淆后的類名的映射文件mapping文件

-optimizations !code/simplification/cast,!field/,!class/merging/ 指定混淆是采用的算法

3. 保持不被混淆的設置

保持某個包下所有類不混淆

-keep class 你的實體類所在的包.** { *; }

四大組件、View體系等不混淆

-keep public class * extends android.app.Activity
-keep public class * extends android.app.Application
-keep public class * extends android.app.Fragment
-keep public class * extends android.support.multidex.MultiDexApplication
-keep public class * extends android.app.Service
-keep public class * extends android.content.BroadcastReceiver
-keep public class * extends android.content.ContentProvider
-keep public class * extends android.preference.Preference
-keep public class * extends android.view.View
-keep class android.support.** {*;}
-keep public class * extends android.support.v4.**

-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);
}

-keepclassmembers public class * extends android.view.View {
   void set*(***);
   *** get*();
}

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet);
    public <init>(android.content.Context, android.util.AttributeSet, int);
}

-keepclassmembers class * extends android.app.Activity {
   public void *(android.view.View);
}

保持 native 方法不被混淆

-keepclasseswithmembernames class * {  
    native <methods>;
}

Serializable

-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();
}

保持枚舉enum類不被混淆

-keepclassmembers enum * {  
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

保持 Parcelable 不被混淆

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

webview

-keepclassmembers class fqcn.of.javascript.interface.for.Webview {
   public *;
}
-keepclassmembers class * extends android.webkit.WebViewClient {
    public void *(android.webkit.WebView, java.lang.String, android.graphics.Bitmap);
    public boolean *(android.webkit.WebView, java.lang.String);
}
-keepclassmembers class * extends android.webkit.WebViewClient {
    public void *(android.webkit.WebView, jav.lang.String);
}

support design

-dontwarn android.support.design.**
-keep class android.support.design.** { *; }
-keep interface android.support.design.** { *; }
-keep public class android.support.design.R$* { *; }

然后就是項目中使用到的第三方包不混淆拴驮，下面有示例春瞬。

4. 完整混淆示例：

#---------------------------------基本指令區(qū)-----------------------

-optimizationpasses 5  #指定代碼的壓縮級別
-dontpreverify  #預校驗
-verbose  #指定日志級別
-dontskipnonpubliclibraryclassmembers
-dontusemixedcaseclassnames  #包名不混合大小寫
-ignorewarnings  #忽略警告
-printmapping proguardMapping.txt  #生成原類名和混淆后的類名的映射文件
-optimizations !code/simplification/cast,!field/*,!class/merging/*  #混淆時所采用的算法
-keepattributes *Annotation*,InnerClasses
-keepattributes Signature
-keepattributes SourceFile,LineNumberTable


#---------------------------------默認保留區(qū)------------------------

#四大組件柴信、View體系等
-keep public class * extends android.app.Activity
-keep public class * extends android.app.Application
-keep public class * extends android.app.Fragment
-keep public class * extends android.support.multidex.MultiDexApplication
-keep public class * extends android.app.Service
-keep public class * extends android.content.BroadcastReceiver
-keep public class * extends android.content.ContentProvider
-keep public class * extends android.preference.Preference
-keep public class * extends android.view.View
-keep class android.support.** {*;}

-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);
}

-keepclassmembers public class * extends android.view.View {
   void set*(***);
   *** get*();
}

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet);
    public <init>(android.content.Context, android.util.AttributeSet, int);
}

-keepclassmembers class * extends android.app.Activity {
   public void *(android.view.View);
}

#Serializable
-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();
}

-keep class **.R$* {
 *;
}

-keepclassmembers class * {
    void *(*Event);
}

#enum
-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keepclasseswithmembernames class * {
    native <methods>;
}

-keepclassmembers class * {
   public <init> (org.json.JSONObject);
}

-keepclasseswithmembernames class * {
    native <methods>;
}

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

#webview
-keepclassmembers class fqcn.of.javascript.interface.for.Webview {
   public *;
}
-keepclassmembers class * extends android.webkit.WebViewClient {
    public void *(android.webkit.WebView, java.lang.String, android.graphics.Bitmap);
    public boolean *(android.webkit.WebView, java.lang.String);
}
-keepclassmembers class * extends android.webkit.WebViewClient {
    public void *(android.webkit.WebView, jav.lang.String);
}

# support design
-dontwarn android.support.design.**
-keep class android.support.design.** { *; }
-keep interface android.support.design.** { *; }
-keep public class android.support.design.R$* { *; }


#---------------------------------第三方包示例-------------------------

#okhttp3.x
-dontwarn com.squareup.okhttp3.**
-keep class com.squareup.okhttp3.** { *;}
-dontwarn okio.**
-dontwarn com.squareup.okhttp.**
-keep class com.squareup.okhttp.{*;}
-dontwarn javax.annotation.**
-keepnames class okhttp3.internal.publicsuffix.PublicSuffixDatabase
-dontwarn org.codehaus.mojo.animal_sniffer.*
-dontwarn okhttp3.internal.platform.ConscryptPlatform

#retrofit
-dontwarn retrofit.**
-keep class retrofit.** { *; }
-keepattributes Signature
-keepattributes Exceptions
-dontwarn okio.**

#Rxjava RxAndroid
-dontwarn rx.*
-dontwarn sun.misc.**

#Glide
-keep public class * implements com.bumptech.glide.module.GlideModule
-keep public enum com.bumptech.glide.load.resource.bitmap.ImageHeaderParser$** {
  **[] $VALUES;
  public *;
}

#Gson
-keep class com.google.gson.** {*;}
-keep class com.google.**{*;}
-keep class sun.misc.Unsafe { *; }
-keep class com.google.gson.stream.** { *; }
-keep class com.google.gson.examples.android.model.** { *; }

#Lambda表達式
-keep class java.lang.invoke.** {*;}
-dontwarn java.lang.invoke.**

#高徳地圖
#3D 地圖
-keepclass com.amap.api.mapcore.**{*;}
-keepclass com.amap.api.maps.**{*;}
-keepclass com.autonavi.amap.mapcore.*{*;}
#定位
-keepclass com.amap.api.location.**{*;}
-keepclass com.loc.**{*;}
-keepclass com.amap.api.fence.**{*;}
-keepclass com.autonavi.aps.amapapi.model.**{*;}
# 搜索
-keepclass com.amap.api.services.**{*;}
# 2D地圖
-keepclass com.amap.api.maps2d.**{*;}
-keepclass com.amap.api.mapcore2d.**{*;}
# 導航
-keepclass com.amap.api.navi.**{*;}
-keepclass com.autonavi.**{*;}


#ButterKnife
-keep class butterknife.** { *; }
-dontwarn butterknife.internal.**
-keep class **$$ViewBinder { *; }
-keepclasseswithmembernames class * {
    @butterknife.* <fields>;
}
-keepclasseswithmembernames class * {
    @butterknife.* <methods>;
}

#eventbus 3.0
-keepattributes *Annotation*
-keepclassmembers class ** {
    @org.greenrobot.eventbus.Subscribe <methods>;
}
-keep enum org.greenrobot.eventbus.ThreadMode { *; }
-keepclassmembers class * extends org.greenrobot.eventbus.util.ThrowableFailureEvent {
    <init>(java.lang.Throwable);
}

#ARouter組件化
-keep public class com.alibaba.android.arouter.routes.**{*;}
-keep public class com.alibaba.android.arouter.facade.**{*;}
-keep class * implements com.alibaba.android.arouter.facade.template.ISyringe{*;}

自己試著用一個簡單的項目加入混淆套啤，打個包試試效果吧。

混淆sdk和避免混淆部分類實戰(zhàn)：

1.在proguard-rules.pro文件下配置混淆參數(shù)和-keep的類或者包：

# 混淆時所采用的算法
-optimizations !code/simplification/arithmetic,!code/simplification/cast,!field/*,!class/merging/*
#指定代碼的壓縮級別
-optimizationpasses 5
-allowaccessmodification
# 優(yōu)化 不優(yōu)化輸入的類文件
-dontoptimize
# 預校驗
-dontpreverify
# 包名不混合大小寫
-dontusemixedcaseclassnames
# 混淆時是否記錄日志
-verbose
# 保護注解
-keepattributes *Annotation*
# 忽略警告
-ignorewarnings

-printconfiguration build/intermediates/proguard-files/full-r8-config.txt

# 保持哪些類不被混淆
#保持sdk中需要暴露功能的包下所有類不被混淆
-keep class com.libo.networkmonitor.api.**{*;}
-keep class com.libo.networkmonitor.impl.NetWorkListener

2.設置release模式下開啟混淆：

    buildTypes {
        release {
            minifyEnabled true
            proguardFiles 'proguard-rules.pro'
        }
        debug {
            minifyEnabled false
            proguardFiles 'proguard-rules.pro'
        }
    }

3.打出sdk的aar包随常，并進行引用查看混淆情況：

可以看到潜沦，打出來的aar包，keep的類可以看到原寫法绪氛，因為上面NetworkMonitor的類避免了混淆可以看得到唆鸡，其余被混淆的類變成了看不出來的字母。

Mapping文件使用

列出了原始的類枣察，方法和字段名與混淆后代碼間的映射争占。這個文件很重要，當你從release版本中收到一個bug報告時序目，混淆后的文件看不出問題臂痕，可以用它來翻譯被混淆的代碼。
mapping目錄在 \app\build\outputs\mapping\release
示例：

或者將mapping文件上傳到監(jiān)測平臺猿涨，報出問題就能直接閱讀了握童。