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hook

    protected 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);
    }

    @Override
    public 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。
     * **/
    @Override
    protected void onInstall(ClassLoader classLoader) throws Throwable {
        new ServiceManagerCacheBinderHook(mHostContext, getServiceName()).onInstall(classLoader);
        mOldObj = getOldObj();
        Class<?> clazz = mOldObj.getClass();//得到class
        List<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;

    @Override
    protected 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";
                    }else
                        startActivity(intent);
                    break;
            }

        } catch (RemoteException e) {
            result = "安装失败 "+e.getMessage();
        }
        tv_val.setText(result);
    }

}

运行程序成功，然后把运行的apk复制一份，我上面的名称是写死的，test.apk，然后放在根目录，点击安装，显示成功后在点击打开，就能见到跳转到插件界面了，插件化通了

接下来就是看自己怎么设计和开发了，什么东西也不能随便使用，得好好考虑，个人觉得插件化不宜大范围使用，适合小菜单的集成，毕竟都是反射的，而且还得考虑好安全问题