Android如何防止apk程式被反編譯

作為Android應用開發人員，不得不面對一個尷尬的局面，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檔案夾

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檔案起作用，先來看看android-sdk-windows\tools\lib\proguard.cfg的內容：

 

-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$Creator *; } -optimizationpasses 5-dontusemixedcaseclassnames-dontskipnonpubliclibraryclasses-dontpreverify-verbose-optimizations !code/simplification/arithmetic,!field/*,!class/merging/*-keep public class * extends android.app.Activity-keep public class * extends android.app.Application-keep public class * extends android.app.Service-keep public class * extends android.content.BroadcastReceiver-keep public class * extends android.content.ContentProvider-keep public class * extends android.app.backup.BackupAgentHelper-keep public class * extends android.preference.Preference-keep public class com.android.vending.licensing.ILicensingService-keepclasseswithmembernames class * {    native <methods>;}-keepclasseswithmembernames class * {    public <init>(android.content.Context, android.util.AttributeSet);}-keepclasseswithmembernames class * {    public <init>(android.content.Context, android.util.AttributeSet, int);}-keepclassmembers enum * {    public static **[] values();    public static ** valueOf(java.lang.String);}-keep class * implements android.os.Parcelable {  public static final android.os.Parcelable$Creator *;}

從指令碼中可以看到，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變數名及類名，所有類中部分以設定了固定參數格式的建構函式，枚舉等等。(詳細資料請參考<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自動產生的default.properties檔案中加上一句“proguard.config=proguard.cfg”就可以了

完整的default.properties檔案應該如下：

 

# 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 # 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，正常的編譯簽名後就可以防止代碼被反編譯了。反編譯經過代碼混淆的apk得到的代碼應該類似於下面的效果，是很難看懂的：

 

如果您使用的是2.3之前的SDK版本也沒關係，把上面的proguard.cfg檔案複製一份放到項目中，然後進行相同的操作即可