ProGuard manual
https://www.guardsquare.com/en/proguard/manual/introduction
ProGuard is a Java class file shrinker, optimizer, obfuscator, and preverifier. The shrinking step detects and removes unused classes, fields, methods and attributes. The optimization step analyzes and optimizes the bytecode of the methods. The obfuscation step renames the remaining classes, fields, and methods using short meaningless names. These first steps make the code base smaller, more efficient, and harder to reverse-engineer. The final preverification step adds preverification information to the classes, which is required for Java Micro Edition and for Java 6 and higher.
Each of these steps is optional. For instance, ProGuard can also be used to just list dead code in an application, or to preverify class files for efficient use in Java 6.
ProGuard_build_process.png
ProGuard first reads the input jars (or aars, wars, ears, zips, apks, or directories). It then subsequently shrinks, optimizes, obfuscates, and preverifies them. You can optionally let ProGuard perform multiple optimization passes. ProGuard writes the processed results to one or more output jars (or aars, wars, ears, zips, apks, or directories). The input may contain resource files, whose names and contents can optionally be updated to reflect the obfuscated class names.
ProGuard requires the library jars (or aars, wars, ears, zips, apks, or directories) of the input jars to be specified. These are essentially the libraries that you would need for compiling the code. ProGuard uses them to reconstruct the class dependencies that are necessary for proper processing. The library jars themselves always remain unchanged. You should still put them in the class path of your final application.
以上，混淆分四步
1.shrink（壓縮）：刪除未被使用到的類，字段，方法和屬性
2.optimize（優化）：分析和優化字節碼
3.obfuscation（混淆）：使用a,b,c這樣簡短的無意義的名稱對類，字段和方法進行重命名，這樣使得，代碼更精簡，效率更高，更難逆向工程
4.preverify（預校驗）：對類添加校驗信息，以符合java對類的要求，保證可執行
#=========================== 基本指令區 start ===========================
#代碼混淆的壓縮比例，值在0-7之間
-optimizationpasses 5
-dontusemixedcaseclassnames #混淆后類名都為小寫
#生成原類名和混淆后的類名的映射文件mapping 類名->轉化后類名的映射
-verbose
#這樣將忽略剩余的警告
-ignorewarnings
#如果應用程序引入的有jar包,并且想混淆jar包里面的class
#-dontskipnonpubliclibraryclasses
#不做預校驗的操作
-dontpreverify
# 混淆時所采用的算法
-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*
#不混淆內部類
-keepattributes Exceptions,InnerClasses
#拋出異常時保留代碼行號
-keepattributes SourceFile,LineNumberTable
#http://stackoverflow.com/questions/5582383/problem-with-proguard-and-roboguice-with-inject-annotations
#不混淆泛型
-keepattributes Signature
#不混淆注解
-keepattributes *Annotation*
#=========================== 基本指令區 end ===========================
#=========================== 默認保留區 start ===========================
#保持 安卓四大組件、Application 不被混淆
-keep public class * extends android.app.Application
-keep public class * extends android.app.Activity
-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.app.backup.BackupAgentHelper
-keep public class * extends android.preference.Preference
-keep public class com.android.vending.licensing.ILicensingService
-keep public class com.google.vending.licensing.ILicensingService
# 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);
}
# 保持 native 方法不被混淆
-keepclasseswithmembernames class * {
native <methods>;
}
# 保持自定義控件類不被混淆
-keepclasseswithmembers class * {
public <init>(android.content.Context, android.util.AttributeSet);
public <init>(android.content.Context, android.util.AttributeSet, int);
}
#保持 枚舉類不被混淆
# For enumeration classes, see http://proguard.sourceforge.net/manual/examples.html#enumerations
-keepclassmembers enum * {
public static **[] values();
public static ** valueOf(java.lang.String);
}
#保持 aidl文件不被混淆
-keep class * implements android.os.Parcelable {
public static final android.os.Parcelable$Creator *;
}
# The support library contains references to newer platform versions.
# Don't warn about those in case this app is linking against an older
# platform version. We know about them, and they are safe.
-dontwarn android.support.**
# 保證 使用JSONObject不報錯
-keepclassmembers class * {
public <init>(org.json.JSONObject);
}
#保持 資源id不被混淆
-keepclassmembers class **.R$* {
public static <fields>;
}
#=========================== 默認保留區 end ===========================
#=========================== 自定義區 start ===========================
#混淆 實體 的類名，但不混淆字段
-keepclassmembers class 包名.model.** { *; }
#不混淆JS
-keepattributes *JavascriptInterface*
#=========================== 自定義區 end ===========================
#=========================== 第三方包 start ===========================
#=========================================================
#對于引用第三方包的情況，可以采用下面方式避免打包出錯：
#-dontwarn com.xx.yy.**
#-keep class com.xx.yy.** { *;}
#=========================================================
#-keep class android.support.v4.** { *;}
#-keep public class * extends android.support.v4.**{
# public protected *;
#}
# 不混淆glide，例子，不需要可以刪除
-keep public class * implements com.bumptech.glide.module.GlideModule
-keep public enum com.bumptech.glide.load.resource.bitmap.ImageHeaderParser$** {
**[] $VALUES;
public *;
}
#-keepresourcexmlelements manifest/application/meta-data@value=GlideModule
#=========================== 第三方包 end ===========================
參考：
1.https://www.guardsquare.com/en/proguard/manual/introduction
2.http://www.lxweimin.com/p/f3455ecaa56e
