Android jar包混淆

具体可参考http://proguard.sourceforge.net/manual/examples.html#library

1、找到android的adt目录下的 D:\soft\adt-bundle-windows-x86\sdk\tools\proguard 文件夹，这个文件夹中有个examples文件夹，打开可看到 android.pro 这是个android混淆代码的demo，你可以完全复制里面的东西，把里面对应的东西改成自己的，然后再添加不要混淆的自己的 类接口等信息 保存为  .pro 文件

2、找到  D:\soft\adt-bundle-windows-x86\sdk\tools\proguard\bin 目录下的 proguardgui.bat 文件双击 会弹出一个图形界面选择左上角的 ProGuard 按钮，然后再右下角有个 Load configuration... 点击选择你的 .pro 文件导入

3、点击图形界面的第二个按钮 Input/Output  添加你要混淆的 jar 或文件夹或其他，对应的也要选择好输出文件对应的东西

4、设置完成后找到左边菜单栏的 Process，选中，然后再页面的右下角找到 process 点击即可完成。

5、 主要混淆后的包一定要测试下。

示例混淆配置文件如下：

#
# This ProGuard configuration file illustrates how to process Android
# applications.
# Usage:
#     java -jar proguard.jar @android.pro
#
# If you're using the Android SDK (version 2.3 or higher), the android tool
# already creates a file like this in your project, called proguard.cfg.
# It should contain the settings of this file, minus the input and output paths
# (-injars, -outjars, -libraryjars, -printmapping, and -printseeds).
# The generated Ant build file automatically sets these paths.

# Specify the input jars, output jars, and library jars.
# Note that ProGuard works with Java bytecode (.class),
# before the dex compiler converts it into Dalvik code (.dex).

-injars  IPS.jar #要混淆的jar包名，注意路径。只写jar包名，则jar包和本混淆配置文件在同一个路径下。
#-injars  libs
-outjars IPSPro.jar #输出的混淆后的jar包

-libraryjars F:/adt-bundle-windows-x86_64-20140321/sdk/platforms/android-19/android.jar #依赖的jar包也需导入，否则会出现找不到类的错误
#-libraryjars /usr/local/android-sdk/add-ons/google_apis-7_r01/libs/maps.jar
# ...

# Save the obfuscation mapping to a file, so you can de-obfuscate any stack
# traces later on.

#-printmapping bin/classes-processed.map

# You can print out the seeds that are matching the keep options below.

#-printseeds bin/classes-processed.seeds

# Preverification is irrelevant for the dex compiler and the Dalvik VM.

-dontpreverify

# Reduce the size of the output some more.

-repackageclasses ''
-allowaccessmodification

# Switch off some optimizations that trip older versions of the Dalvik VM.

-optimizations !code/simplification/arithmetic

# Keep a fixed source file attribute and all line number tables to get line
# numbers in the stack traces.
# You can comment this out if you're not interested in stack traces.

-renamesourcefileattribute SourceFile
-keepattributes SourceFile,LineNumberTable

# RemoteViews might need annotations.

-keepattributes *Annotation*

# Preserve all fundamental application classes.

-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

# Preserve all View implementations, their special context constructors, and
# their setters.

-keep public class * extends android.view.View {
    public <init>(android.content.Context);
    public <init>(android.content.Context, android.util.AttributeSet);
    public <init>(android.content.Context, android.util.AttributeSet, int);
    public void set*(...);
}

# Preserve all classes that have special context constructors, and the
# constructors themselves.

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet);
}

# Preserve all classes that have special context constructors, and the
# constructors themselves.

-keepclasseswithmembers class * {
    public <init>(android.content.Context, android.util.AttributeSet, int);
}

# Preserve the special fields of all Parcelable implementations.

-keepclassmembers class * implements android.os.Parcelable {
    static android.os.Parcelable$Creator CREATOR;
}

# Preserve static fields of inner classes of R classes that might be accessed
# through introspection.

-keepclassmembers class **.R$* {
  public static <fields>;
}

# Preserve the required interface from the License Verification Library
# (but don't nag the developer if the library is not used at all).

-keep public interface com.android.vending.licensing.ILicensingService

-dontnote com.android.vending.licensing.ILicensingService

# The Android Compatibility library references some classes that may not be
# present in all versions of the API, but we know that's ok.

-dontwarn android.support.**

# Preserve all native method names and the names of their classes.

-keepclasseswithmembernames class * {
    native <methods>;
}

# Preserve the special static methods that are required in all enumeration
# classes.

-keepclassmembers class * extends java.lang.Enum {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

# Explicitly preserve all serialization members. The Serializable interface
# is only a marker interface, so it wouldn't save them.
# You can comment this out if your application doesn't use serialization.
# If your code contains serializable classes that have to be backward
# compatible, please refer to the manual.

-keepclassmembers class * implements java.io.Serializable {
    static final long serialVersionUID;
    static final java.io.ObjectStreamField[] serialPersistentFields;
    private void writeObject(java.io.ObjectOutputStream);
    private void readObject(java.io.ObjectInputStream);
    java.lang.Object writeReplace();
    java.lang.Object readResolve();
}

# Your application may contain more items that need to be preserved;
# typically classes that are dynamically created using Class.forName:

 -keep public class com.dkdh.ips.StepDetector{
   # public <fields>;
    public <methods>;
 }
 -keep public class com.dkdh.ips.SensorFusion{
   # public <fields>;
   public <methods>;
 }
 #不混淆异常，内部类等
 -keepattributes Exceptions,InnerClasses,Signature,Deprecated,
                SourceFile,LineNumberTable,*Annotation*,EnclosingMethod

#  -keep public class com.dkdh.ips.Util{
#    public <fields>;
#   public <methods>;
# }
  -keep  class com.dkdh.ips.IPSSensorManager{
  public static boolean getRotationMatrix(float[],float[],float[],float[]);#只保留该方法不混淆，其他所有全部混淆
   # public <fields>;
   #public <methods>;
 }
#  -keep  class com.dkdh.ips.SensorFusion.calculateFusedOrientationTask{
#    public <fields>;
#   public <methods>;
# }
# -keep public interface mypackage.MyInterface
# -keep public class * implements mypackage.MyInterface

出现Error: The output jar is empty. Did you specify the proper '-keep' options?错误，

是因为混淆的代码没有一个入口，也就是说，这个程序或者jar包被全部混淆了，外部没有任何一个地方可以正常调用到它，换句话说就是“混淆出来的东西没法用”。

混淆时，要暴露的接口、变量和方法不能混淆，一般是public修饰不要混淆。