作為Android應用開發者,不得不面對一個尴尬的局面,就是自己辛辛苦苦開發的應用可以被別人很輕易的就反編譯出來。
Google似乎也發現了這個問題,從SDK2.3開始我們可以看到在android-sdk-windows\tools\下面多了一個proguard文件夾
proguard是一個java代碼混淆的工具,通過proguard,別人即使反編譯你的apk包,也只會看到一些讓人很難看懂的代碼,從而達到保護代碼的作用。
下面具體說一說怎麼樣讓SDK2.3下的proguard.cfg文件起作用,先來看看android-sdk-windows\tools\lib\proguard.cfg的內容:
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-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 *;
}
從腳本中可以看到,混淆中保留了繼承自Activity、Service、Application、BroadcastReceiver、 ContentProvider等基本組件以及com.android.vending.licensing.ILicensingService,
並保留了所有的Native變量名及類名,所有類中部分以設定了固定參數格式的構造函數,枚舉等等。(詳細信息請參考<proguard_path>/examples中的例子及注釋。)
讓proguard.cfg起作用的做法很簡單,就是在eclipse自動生成的default.properties文件中加上一句“proguard.config=proguard.cfg”就可以了
完整的default.properties文件應該如下:
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# 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-9
proguard.config=proguard.cfg