DroidPlugin插件化开发

360手机助手使用的 DroidPlugin，它是360手机助手团队在Android系统上实现了一种插件机制。它可以在无需安装、修改的情况下运行APK文件,此机制对改进大型APP的架构，实现多团队协作开发具有一定的好处。

它是一种新的插件机制，一种免安装的运行机制

github地址： https://github.com/DroidPluginTeam/DroidPlugin

参考博客：http://blog.csdn.net/hejjunlin/article/details/52124397

下载地址：http://download.csdn.net/detail/u010864175/9806093

DroidPlugin的的基本原理：

　　共享进程：为android提供一个进程运行多个apk的机制，通过API欺骗机制瞒过系统

　　占坑：通过预先占坑的方式实现不用在manifest注册，通过一带多的方式实现服务管理

　　Hook机制：动态代理实现函数hook，Binder代理绕过部分系统服务限制，IO重定向（先获取原始Object-->Read,然后动态代理Hook Object后-->Write回去，达到瞒天过海的目的）

public abstract class Hook {private boolean mEnable = false;//能否hookprotected Context mHostContext;//宿主context,外部传入protected BaseHookHandle mHookHandles;public void setEnable(boolean enable, boolean reInstallHook) {this.mEnable = enable;}public final void setEnable(boolean enable) {setEnable(enable, false);}public boolean isEnable() {return mEnable;}protected Hook(Context hostContext) {mHostContext = hostContext;mHookHandles = createHookHandle();}protected abstract BaseHookHandle createHookHandle();//用于子类创建Hook机制protected abstract void onInstall(ClassLoader classLoader) throws Throwable;//插件安装protected void onUnInstall(ClassLoader classLoader) throws Throwable {//插件卸载
}
}

public class HookedMethodHandler {//Hook方法private static final String TAG = HookedMethodHandler.class.getSimpleName();protected final Context mHostContext;/***  调用方法的时候会到AppOpsService进行判断uid（宿主apk）和插件的包名是否匹配，此处是不匹配的*  此时就可以经过转换欺骗系统让程序认为是宿主apk调过来的（这样的前提就需要宿主把所有的权限都申请了）*  因为系统只会去检测宿主apk* **/private Object mFakedResult = null;//用于欺骗系统private boolean mUseFakedResult = false;public HookedMethodHandler(Context hostContext) {this.mHostContext = hostContext;}public synchronized Object doHookInner(Object receiver, Method method, Object[] args) throws Throwable {long b = System.currentTimeMillis();try {mUseFakedResult = false;mFakedResult = null;boolean suc = beforeInvoke(receiver, method, args);Object invokeResult = null;if (!suc) {//false执行原始方法invokeResult = method.invoke(receiver, args);}afterInvoke(receiver, method, args, invokeResult);if (mUseFakedResult) {//true返回欺骗结果，false返回正常的调用方法return mFakedResult;} else {return invokeResult;}} finally {long time = System.currentTimeMillis() - b;if (time > 5) {Log.i(TAG, "doHookInner method(%s.%s) cost %s ms", method.getDeclaringClass().getName(), method.getName(), time);}}}public void setFakedResult(Object fakedResult) {this.mFakedResult = fakedResult;mUseFakedResult = true;}/*** 在某个方法被调用之前执行，如果返回true，则不执行原始的方法，否则执行原始方法*/protected boolean beforeInvoke(Object receiver, Method method, Object[] args) throws Throwable {return false;}protected void afterInvoke(Object receiver, Method method, Object[] args, Object invokeResult) throws Throwable {}public boolean isFakedResult() {return mUseFakedResult;}public Object getFakedResult() {return mFakedResult;}
}

abstract class BinderHook extends Hook implements InvocationHandler {private Object mOldObj;public BinderHook(Context hostContext) {super(hostContext);}@Overridepublic Object invoke(Object proxy, Method method, Object[] args) throws Throwable {try {if (!isEnable()) {//如果不能Hook，执行原方法return method.invoke(mOldObj, args);}HookedMethodHandler hookedMethodHandler = mHookHandles.getHookedMethodHandler(method);if (hookedMethodHandler != null) {return hookedMethodHandler.doHookInner(mOldObj, method, args);} else {return method.invoke(mOldObj, args);}} catch (InvocationTargetException e) {Throwable cause = e.getTargetException();if (cause != null && MyProxy.isMethodDeclaredThrowable(method, cause)) {throw cause;} else if (cause != null) {RuntimeException runtimeException = !TextUtils.isEmpty(cause.getMessage()) ? new RuntimeException(cause.getMessage()) : new RuntimeException();runtimeException.initCause(cause);throw runtimeException;} else {RuntimeException runtimeException = !TextUtils.isEmpty(e.getMessage()) ? new RuntimeException(e.getMessage()) : new RuntimeException();runtimeException.initCause(e);throw runtimeException;}} catch (IllegalArgumentException e) {try {StringBuilder sb = new StringBuilder();sb.append(" DROIDPLUGIN{");if (method != null) {sb.append("method[").append(method.toString()).append("]");} else {sb.append("method[").append("NULL").append("]");}if (args != null) {sb.append("args[").append(Arrays.toString(args)).append("]");} else {sb.append("args[").append("NULL").append("]");}sb.append("}");String message = e.getMessage() + sb.toString();throw new IllegalArgumentException(message, e);} catch (Throwable e1) {throw e;}} catch (Throwable e) {if (MyProxy.isMethodDeclaredThrowable(method, e)) {throw e;} else {RuntimeException runtimeException = !TextUtils.isEmpty(e.getMessage()) ? new RuntimeException(e.getMessage()) : new RuntimeException();runtimeException.initCause(e);throw runtimeException;}}}abstract Object getOldObj() throws Exception;void setOldObj(Object mOldObj) {this.mOldObj = mOldObj;}public abstract String getServiceName();//具体Hook哪一个service/*** 先调用ServiceManagerCacheBinderHook的onInstall()方法更新一下service cache* 然后生成一个新的代理对象放到mProxiedObjCache里。这样下次不管是从cache里取，还是直接通过binder调用，就都会返回我们的代理对象。* **/@Overrideprotected void onInstall(ClassLoader classLoader) throws Throwable {new ServiceManagerCacheBinderHook(mHostContext, getServiceName()).onInstall(classLoader);mOldObj = getOldObj();Class<?> clazz = mOldObj.getClass();//得到classList<Class<?>> interfaces = Utils.getAllInterfaces(clazz);Class[] ifs = interfaces != null && interfaces.size() > 0 ? interfaces.toArray(new Class[interfaces.size()]) : new Class[0];//用原始对象的classloader传入动态代理，得到代理对象Object proxiedObj = MyProxy.newProxyInstance(clazz.getClassLoader(), ifs, this);MyServiceManager.addProxiedObj(getServiceName(), proxiedObj);}
}

结论就是读取插件apk，和宿主的uid对比，然后进行包替换，在利用binder代理Hook，启动插件，这概括很是大概，不过涉及太复杂

然后是使用了，结束和使用都很多资料，很详细，不过自己研究了一翻记录下心得，也能加深理解和印象

public class MainActivity extends AppCompatActivity {private String filepath = null, packageName = "cn.liuzhen.plugin";private TextView tv_val;private Context context;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);context = MainActivity.this;tv_val = (TextView)findViewById(R.id.tv_val);filepath = Environment.getExternalStorageDirectory().getAbsolutePath().concat("/test.apk");}public void click(View view) {if (filepath == null){Toast.makeText(context,"filepath is null",Toast.LENGTH_SHORT).show();return;}String result = null;int code = -1;try {switch (view.getId()) {case R.id.btn_install:code = PluginManager.getInstance().installPackage(filepath, PackageManagerCompat.INSTALL_REPLACE_EXISTING);result = "install";switch (code) {case PluginManager.INSTALL_FAILED_NO_REQUESTEDPERMISSION:result = "安装失败，文件请求的权限太多";break;case PackageManagerCompat.INSTALL_FAILED_NOT_SUPPORT_ABI:result = "宿主不支持插件的abi环境，可能宿主运行时为64位，但插件只支持32位";break;case PackageManagerCompat.INSTALL_SUCCEEDED:result = "安装完成";break;}break;case R.id.btn_del:PluginManager.getInstance().deletePackage(packageName, 0);result = "del";break;case R.id.btn_open:PackageManager pm = getPackageManager();Intent intent = pm.getLaunchIntentForPackage("cn.liuzhen.plugin");if (intent == null){result = "intent is null";}elsestartActivity(intent);break;}} catch (RemoteException e) {result = "安装失败 "+e.getMessage();}tv_val.setText(result);}}