作为Android应用开发者,不得不面对一个尴尬的局面,就是自己辛辛苦苦开发的应用可以被别人很轻易的就反编译出来。Google似乎也发现了这个问题,从SDK2.3开始我们可以看到在android-sdk-windows\tools\下面多了一个proguard文件夹proguard是一个java代码混淆的工具,通过proguard,别人即使反编译你的apk包,也只会看到一些让人很难看懂的代码,从而达到保护代码的作用。下面具体说一说怎么样让SDK2.3下的proguard.cfg文件起作用,先来看看android-sdk-windows\tools\lib\proguard.cfg的内容:[html] view plaincopyprint?1.-optimizationpasses 5 2.-dontusemixedcaseclassnames 3.-dontskipnonpubliclibraryclasses 4.-dontpreverify 5.-verbose 6.-optimizations !code/simplification/arithmetic,!field/*,!class/merging/* 7. 8.-keep public class * extends android.app.Activity 9.-keep public class * extends android.app.Application 10.-keep public class * extends android.app.Service 11.-keep public class * extends android.content.BroadcastReceiver 12.-keep public class * extends android.content.ContentProvider 13.-keep public class * extends android.app.backup.BackupAgentHelper 14.-keep public class * extends android.preference.Preference 15.-keep public class com.android.vending.licensing.ILicensingService 16. 17.-keepclasseswithmembernames class * { 18. native <methods>; 19.} 20. 21.-keepclasseswithmembernames class * { 22. public <init>(android.content.Context, android.util.AttributeSet); 23.} 24. 25.-keepclasseswithmembernames class * { 26. public <init>(android.content.Context, android.util.AttributeSet, int); 27.} 28. 29.-keepclassmembers enum * { 30. public static **[] values(); 31. public static ** valueOf(java.lang.String); 32.} 33. 34.-keep class * implements android.os.Parcelable { 35. public static final android.os.Parcelable$Creator *; 36.} -optimizationpasses 5-dontusemixedcaseclassnames-dontskipnonpubliclibraryclasses-dontpreverify-verbose-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*-keep public class * extends android.app.Activity-keep public class * extends android.app.Application-keep public class * extends android.app.Service-keep public class * extends android.content.BroadcastReceiver-keep public class * extends android.content.ContentProvider-keep public class * extends android.app.backup.BackupAgentHelper-keep public class * extends android.preference.Preference-keep public class com.android.vending.licensing.ILicensingService-keepclasseswithmembernames class * { native <methods>;}-keepclasseswithmembernames class * { public <init>(android.content.Context, android.util.AttributeSet);}-keepclasseswithmembernames class * { public <init>(android.content.Context, android.util.AttributeSet, int);}-keepclassmembers enum * { public static **[] values(); public static ** valueOf(java.lang.String);}-keep class * implements android.os.Parcelable { public static final android.os.Parcelable$Creator *;}从脚本中可以看到,混淆中保留了继承自Activity、Service、Application、BroadcastReceiver、ContentProvider等基本组件以及com.android.vending.licensing.ILicensingService,并保留了所有的Native变量名及类名,所有类中部分以设定了固定参数格式的构造函数,枚举等等。(详细信息请参考<proguard_path>/examples中的例子及注释。)让proguard.cfg起作用的做法很简单,就是在eclipse自动生成的default.properties文件中加上一句“proguard.config=proguard.cfg”就可以了完整的default.properties文件应该如下:[html] view plaincopyprint?1.# This file is automatically generated by Android Tools. 2.# Do not modify this file -- YOUR CHANGES WILL BE ERASED! 3.# 4.# This file must be checked in Version Control Systems. 5.# 6.# To customize properties used by the Ant build system use, 7.# "build.properties", and override values to adapt the script to your 8.# project structure. 9. 10.# Project target. 11.target=android-9 12.proguard.config=proguard.cfg # This file is automatically generated by Android Tools.# Do not modify this file -- YOUR CHANGES WILL BE ERASED!## This file must be checked in Version Control Systems.## To customize properties used by the Ant build system use,# "build.properties", and override values to adapt the script to your# project structure.# Project target.target=android-9proguard.config=proguard.cfg大功告成,正常的编译签名后就可以防止代码被反编译了。反编译经过代码混淆的apk得到的代码应该类似于下面的效果,是很难看懂的:如果您使用的是2.3之前的SDK版本也没关系,把上面的proguard.cfg文件复制一份放到项目中,然后进行相同的操作即可。
