android 笔记之代码混淆

一、什么是混淆代码

Java是一种跨平台的、解释型语言，Java 源代码编译成中间”字节码”存储于 class 文件中。由于跨平台的需要，Java 字节码中包括了很多源代码信息，如变量名、方法名，并且通过这些名称来访问变量和方法，这些符号带有许多语义信息，很容易被反编译成 Java 源代码。为了防止这种现象，我们可以使用 Java 混淆器对 Java 字节码进行混淆。

混淆就是对发布出去的程序进行重新组织和处理，使得处理后的代码与处理前代码完成相同的功能，而混淆后的代码很难被反编译，即使反编译成功也很难得出程序的真正语义。被混淆过的程序代码，仍然遵照原来的档案格式和指令集，执行结果也与混淆前一样，只是混淆器将代码中的所有变量、函数、类的名称变为简短的英文字母代号，在缺乏相应的函数名和程序注释的况下，即使被反编译，也将难以阅读。同时混淆是不可逆的，在混淆的过程中一些不影响正常运行的信息将永久丢失，这些信息的丢失使程序变得更加难以理解。混淆器的作用不仅仅是保护代码，它也有精简编译后程序大小的作用。由于以上介绍的缩短变量和函数名以及丢失部分信息的原因， 编译后 jar 文件体积大约能减少25% ，这对当前费用较贵的无线网络传输是有一定意义的。

二、混淆打包注意

ProGuard来进行混洗打包，大大的优化Apk包的大小。但是注意ProGuard对文件路径的名名很有讲究，不支持括号，也不支持空格。在混淆过后，可以在工程目录的proguard中的mapping.txt看到混淆后的类名，方法名，变量名和混淆前的类名，方法名，变量名。三、混淆代码（1.2步骤不分先后）1、首先在在eclipse项目目录下project.properties文件里面如图，去掉圈中那句前面的#，即进行混淆。2、然后在eclipse项目目录下 proguard-project.tx文件里面进行项目属性的配置，主要是对一些不需要混淆的（如第三方jar包，sdk，源生.......）配置。混淆文件proguard.cfg 参数详解注释：

-optimizationpasses 5                                                           # 指定代码的压缩级别
-dontusemixedcaseclassnames                                                     # 是否使用大小写混合
-dontskipnonpubliclibraryclasses                                                # 是否混淆第三方jar
-dontpreverify                                                                  # 混淆时是否做预校验
-verbose                                                                        # 混淆时是否记录日志
-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*        # 混淆时所采用的算法

-keep public class * extends android.app.Activity                               # 保持哪些类不被混淆
-keep public class * extends android.app.Application                            # 保持哪些类不被混淆
-keep public class * extends android.app.Service                                # 保持哪些类不被混淆
-keep public class * extends android.content.BroadcastReceiver                  # 保持哪些类不被混淆
-keep public class * extends android.content.ContentProvider                    # 保持哪些类不被混淆
-keep public class * extends android.app.backup.BackupAgentHelper               # 保持哪些类不被混淆
-keep public class * extends android.preference.Preference                      # 保持哪些类不被混淆
-keep public class com.android.vending.licensing.ILicensingService              # 保持哪些类不被混淆

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

-keepclasseswithmembers class * {                                               # 保持自定义控件类不被混淆
public <init>(android.content.Context, android.util.AttributeSet);
}

-keepclasseswithmembers class * {
public <init>(android.content.Context, android.util.AttributeSet, int);     # 保持自定义控件类不被混淆
}

-keepclassmembers class * extends android.app.Activity {                        # 保持自定义控件类不被混淆
public void *(android.view.View);
}

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

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

-keep class MyClass;                                                            # 保持自己定义的类不被混淆

A、混淆打包第三方jar包的处理：proguard-project.tx 配置如下：-optimizationpasses 5-dontusemixedcaseclassnames-dontskipnonpubliclibraryclasses-dontpreverify-verbose-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*#忽略警告 也可以用-ignorewarnings-dontwarnB.#声明第三方jar包,把所有你项目的jar包都申明进来(如果有so文件可以不管)，例如：-libraryjars libs/apns_1.0.6.jar-libraryjars libs/armeabi/libBaiduMapSDK_v2_3_1.so-libraryjars libs/armeabi/liblocSDK4.so-libraryjars libs/baidumapapi_v2_3_1.jar-libraryjars libs/core.jar-libraryjars libs/gesture-imageview.jar-libraryjars libs/gson-2.0.jar-libraryjars libs/infogracesound.jar-libraryjars libs/locSDK_4.0.jar-libraryjars libs/ormlite-Android-4.48.jar-libraryjars libs/ormlite-core-4.48.jar-libraryjars libs/universal-image-loader-1.9.0.jarC. 将你不需要混淆的部分申明进来，因为有些类经过混淆会导致程序编译不通过，如下：-keep public class * extends android.app.Fragment-keep public class * extends android.app.Activity-keep public class * extends android.app.Application-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 * extends android.support.v4.**-keep public class com.android.vending.licensing.ILicensingService--以上都是API里边的类，最好都要避免混淆D、#不混淆第三方jar包中的类有些很特殊的，例如百度地图，你需要添加以下申明：-keep class com.baidu.** { *; }-keep class vi.com.gdi.bgl.android.**{*;}一般model最好避免混淆（model无关紧要，不混淆也没多大关系）如：-keep class com.bank.pingan.model.** { *; }-keep class com.baidu.mapapi.** {*;}-keep class com.tencent.tauth.** {*;}-keep class org.apache.http.entity.mime.**{*;}-keep class android.support.v4.** {*;}-keep class android.net.http.**{*;}-keep class com.weibo.sdk.android.** {*;}-keep class com.sina.sso.** {*;}至此基本上配置完成。其实可以把混淆文件proguard.cfg 参数详解注释： 直接复制到proguard-project.txt文件中，然后添加自己的libs下面的jar包和不要混淆的第三方包的类。不足之处望指出，相互学习。下面是一个配置完成的proguard-project.txt文件，可以参考下。To enable ProGuard in your project, edit project.properties# to define the proguard.config property as described in that file.## Add project specific ProGuard rules here.# By default, the flags in this file are appended to flags specified# in ${sdk.dir}/tools/proguard/proguard-android.txt# You can edit the include path and order by changing the ProGuard# include property in project.properties.## For more details, see# http://developer.android.com/guide/developing/tools/proguard.html # Add any project specific keep options here:# If your project uses WebView with JS, uncomment the following# and specify the fully qualified class name to the JavaScript interface# class:#-keepclassmembers class fqcn.of.javascript.interface.for.webview {# public *;#}-optimizationpasses 5-dontusemixedcaseclassnames-dontskipnonpubliclibraryclasses-dontpreverify-verbose-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*-keepattributes *Annotation*-keepattributes Signature-libraryjars libs/apns_1.0.6.jar-libraryjars libs/armeabi/libBaiduMapSDK_v2_3_1.so-libraryjars libs/armeabi/liblocSDK4.so-libraryjars libs/baidumapapi_v2_3_1.jar-libraryjars libs/core.jar-libraryjars libs/gesture-imageview.jar-libraryjars libs/gson-2.0.jar-libraryjars libs/infogracesound.jar-libraryjars libs/locSDK_4.0.jar-libraryjars libs/ormlite-android-4.48.jar-libraryjars libs/ormlite-core-4.48.jar-libraryjars libs/universal-image-loader-1.9.0.jar-keep class com.baidu.** { *; }-keep class vi.com.gdi.bgl.android.**{*;}-keep public class * extends android.app.Fragment-keep public class * extends android.app.Activity-keep public class * extends android.app.Application-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 * extends android.support.v4.**-keep public class com.android.vending.licensing.ILicensingService-keep class com.google.gson.stream.** { *; }-keep class com.google.gson.examples.android.model.** { *; }-keep class com.uuhelper.Application.** { *; }-keep class net.sourceforge.zbar.** { *; }-keep class com.google.android.gms.** { *; }-keep class com.bank.pingan.model.** { *; }-keep public class * extends com.j256.ormlite.android.apptools.OrmLiteSqliteOpenHelper-keep public class * extends com.j256.ormlite.android.apptools.OpenHelperManager-keep class com.android.vending.licensing.ILicensingService-keep class android.support.v4.** { *; }-keep class org.apache.commons.net.** { *; }-keep class com.tencent.** { *; }-keep class com.umeng.** { *; }-keep class com.umeng.analytics.** { *; }-keep class com.umeng.common.** { *; }-keep class com.umeng.newxp.** { *; }-keep class com.j256.ormlite.** { *; }-keep class com.j256.ormlite.android.** { *; }-keep class com.j256.ormlite.field.** { *; }-keep class com.j256.ormlite.stmt.** { *; }-dontwarn android.support.v4.**-dontwarn org.apache.commons.net.**-dontwarn com.tencent.**-keepclasseswithmembernames class * {native <methods>;}-keepclasseswithmembernames class * {public <init>(android.content.Context, android.util.AttributeSet);}-keepclasseswithmembernames class * {public <init>(android.content.Context, android.util.AttributeSet, int);}-keepclassmembers enum * {public static **[] values();public static ** valueOf(java.lang.String);}-keep class * implements android.os.Parcelable {public static final android.os.Parcelable$Creator *;}-keepclasseswithmembers class * {public <init>(android.content.Context);}-dontshrink-dontoptimize-dontwarn com.google.android.maps.**-dontwarn android.webkit.WebView-dontwarn com.umeng.**-dontwarn com.tencent.weibo.sdk.**-dontwarn com.facebook.**-keep enum com.facebook.**-keepattributes Exceptions,InnerClasses,Signature-keepattributes *Annotation*-keepattributes SourceFile,LineNumberTable-keep public interface com.facebook.**-keep public interface com.tencent.**-keep public interface com.umeng.socialize.**-keep public interface com.umeng.socialize.sensor.**-keep public interface com.umeng.scrshot.**-keep public class com.umeng.socialize.* {*;}-keep public class javax.**-keep public class android.webkit.**-keep class com.facebook.**-keep class com.umeng.scrshot.**-keep public class com.tencent.** {*;}-keep class com.umeng.socialize.sensor.**-keep class com.tencent.mm.sdk.openapi.WXMediaMessage {*;}-keep class com.tencent.mm.sdk.openapi.** implements com.tencent.mm.sdk.openapi.WXMediaMessage$IMediaObject {*;}-keep class im.yixin.sdk.api.YXMessage {*;}-keep class im.yixin.sdk.api.** implements im.yixin.sdk.api.YXMessage$YXMessageData{*;}-keep public class [your_pkg].R$*{public static final int *;}