插件化开发---DroidPlugin对Servie的管理

Service分为两种形式：以startService启动的服务和用bindService绑定的服务；由于这两个过程大体相似，这里以稍复杂的bindService为例分析Service组件的工作原理。

绑定Service的过程是通过Context类的bindService完成的，这个方法需要三个参数：第一个参数代表想要绑定的Service的Intent，第二个参数是一个ServiceConnetion，我们可以通过这个对象接收到Service绑定成功或者失败的回调；第三个参数则是绑定时候的一些FLAG

Context的具体实现在ContextImpl类，ContextImpl中的bindService方法直接调用了bindServiceCommon方法，此方法源码如下：

    /** @hide */    @Override    public boolean bindServiceAsUser(Intent service, ServiceConnection conn, int flags,            UserHandle user) {        return bindServiceCommon(service, conn, flags, user);    }    private boolean bindServiceCommon(Intent service, ServiceConnection conn, int flags,            UserHandle user) {        IServiceConnection sd;        if (conn == null) {            throw new IllegalArgumentException("connection is null");        }        if (mPackageInfo != null) {            sd = mPackageInfo.getServiceDispatcher(conn, getOuterContext(),                    mMainThread.getHandler(), flags);        } else {            throw new RuntimeException("Not supported in system context");        }        validateServiceIntent(service);        try {            IBinder token = getActivityToken();            if (token == null && (flags&BIND_AUTO_CREATE) == 0 && mPackageInfo != null                    && mPackageInfo.getApplicationInfo().targetSdkVersion                    < android.os.Build.VERSION_CODES.ICE_CREAM_SANDWICH) {                flags |= BIND_WAIVE_PRIORITY;            }            service.prepareToLeaveProcess();            int res = ActivityManagerNative.getDefault().bindService(                mMainThread.getApplicationThread(), getActivityToken(),                service, service.resolveTypeIfNeeded(getContentResolver()),                sd, flags, user.getIdentifier());            if (res < 0) {                throw new SecurityException(                        "Not allowed to bind to service " + service);            }            return res != 0;        } catch (RemoteException e) {            return false;        }    }

大致观察就能发现这个方法最终通过ActivityManagerNative借助AMS进而完成Service的绑定过程，在跟踪AMS的bindService源码之前，我们关注一下这个方法开始处创建的sd变量。这个变量的类型是IServiceConnection，如果读者还有印象，我们在 广播的管理 一文中也遇到过类似的处理方式——IIntentReceiver；所以，这个IServiceConnection与IApplicationThread以及IIntentReceiver相同，都是ActivityThread给AMS提供的用来与之进行通信的Binder对象；这个接口的实现类为LoadedApk.ServiceDispatcher。

bindService这个方法相当简单，只是做了一些参数校检之后直接调用了ActivityServices类的bindServiceLocked方法：

int bindServiceLocked(IApplicationThread caller, IBinder token, Intent service,        String resolvedType, IServiceConnection connection, int flags,        String callingPackage, int userId) throws TransactionTooLargeException {    final ProcessRecord callerApp = mAm.getRecordForAppLocked(caller);    // 参数校检，略    ServiceLookupResult res =        retrieveServiceLocked(service, resolvedType, callingPackage,                Binder.getCallingPid(), Binder.getCallingUid(), userId, true, callerFg);    // 结果校检， 略    ServiceRecord s = res.record;    final long origId = Binder.clearCallingIdentity();    try {        // ... 不关心， 略        mAm.startAssociationLocked(callerApp.uid, callerApp.processName,                s.appInfo.uid, s.name, s.processName);        AppBindRecord b = s.retrieveAppBindingLocked(service, callerApp);        ConnectionRecord c = new ConnectionRecord(b, activity,                connection, flags, clientLabel, clientIntent);        IBinder binder = connection.asBinder();        ArrayList<ConnectionRecord> clist = s.connections.get(binder);        // 对connection进行处理， 方便存取，略        clist.add(c);        if ((flags&Context.BIND_AUTO_CREATE) != 0) {            s.lastActivity = SystemClock.uptimeMillis();            if (bringUpServiceLocked(s, service.getFlags(), callerFg, false) != null) {                return 0;            }        }        // 与BIND_AUTO_CREATE不同的启动FLAG，原理与后续相同，略    } finally {        Binder.restoreCallingIdentity(origId);    }    return 1;}

这个方法比较长，我这里省去了很多无关代码，只列出关键逻辑；首先它通过retrieveServiceLocked方法获取到了intent匹配到的需要bind到的Service组件res；然后把ActivityThread传递过来的IServiceConnection使用ConnectionRecord进行了包装，方便接下来使用；最后如果启动的FLAG为BIND_AUTO_CREATE，那么调用bringUpServiceLocked开始创建Service，

在bringUpServiceLocked方法中进行判断，如果Service所在的进程已经启动，那么直接调用realStartServiceLocked方法来真正启动Service组件；如果Service所在的进程还没有启动，那么先在AMS中记下这个要启动的Service组件，然后通过startProcessLocked启动新的进程。

我们先看Service进程已经启动的情况，也即realStartServiceLocked分支：

private final void realStartServiceLocked(ServiceRecord r,        ProcessRecord app, boolean execInFg) throws RemoteException {    // 略。。    boolean created = false;    try {        synchronized (r.stats.getBatteryStats()) {            r.stats.startLaunchedLocked();        }        mAm.ensurePackageDexOpt(r.serviceInfo.packageName);        app.forceProcessStateUpTo(ActivityManager.PROCESS_STATE_SERVICE);        app.thread.scheduleCreateService(r, r.serviceInfo,                mAm.compatibilityInfoForPackageLocked(r.serviceInfo.applicationInfo),                app.repProcState);        r.postNotification();        created = true;    } catch (DeadObjectException e) {        mAm.appDiedLocked(app);        throw e;    } finally {        // 略。。    }    requestServiceBindingsLocked(r, execInFg);    // 不关心，略。。}

这个方法首先调用了app.thread的scheduleCreateService方法，我们知道，这是一个IApplicationThread对象，它是App所在进程提供给AMS的用来与App进程进行通信的Binder对象，这个Binder的Server端在ActivityThread的ApplicationThread类，因此，我们跟踪ActivityThread类，这个方法的实现如下：

public final void scheduleCreateService(IBinder token,        ServiceInfo info, CompatibilityInfo compatInfo, int processState) {    updateProcessState(processState, false);    CreateServiceData s = new CreateServiceData();    s.token = token;    s.info = info;    s.compatInfo = compatInfo;    sendMessage(H.CREATE_SERVICE, s);}

它不过是转发了一个消息给ActivityThread的H这个Handler，H类收到这个消息之后，直接调用了ActivityThread类的handleCreateService方法，如下：

private void handleCreateService(CreateServiceData data) {    unscheduleGcIdler();    LoadedApk packageInfo = getPackageInfoNoCheck(            data.info.applicationInfo, data.compatInfo);    Service service = null;    try {        java.lang.ClassLoader cl = packageInfo.getClassLoader();        service = (Service) cl.loadClass(data.info.name).newInstance();    } catch (Exception e) {    }    try {        ContextImpl context = ContextImpl.createAppContext(this, packageInfo);        context.setOuterContext(service);        Application app = packageInfo.makeApplication(false, mInstrumentation);        service.attach(context, this, data.info.name, data.token, app,                ActivityManagerNative.getDefault());        service.onCreate();        mServices.put(data.token, service);        try {            ActivityManagerNative.getDefault().serviceDoneExecuting(                    data.token, SERVICE_DONE_EXECUTING_ANON, 0, 0);        } catch (RemoteException e) {            // nothing to do.        }    } catch (Exception e) {    }}

看到这段代码，是不是似曾相识？！没错，这里与Activity组件的创建过程如出一辙！所以这里就不赘述了，可以参阅 Activity生命周期管理。

需要注意的是，这里Service类的创建过程与Activity是略微有点不同的，虽然都是通过ClassLoader通过反射创建，但是Activity却把创建过程委托给了Instrumentation类，而Service则是直接进行。
OK，现在ActivityThread里面的handleCreateService方法成功创建出了Service对象，并且调用了它的onCreate方法；到这里我们的Service已经启动成功。scheduleCreateService这个Binder调用过程结束，代码又回到了AMS进程的realStartServiceLocked方法

app.thread.scheduleCreateService(r, r.serviceInfo,                mAm.compatibilityInfoForPackageLocked(r.serviceInfo.applicationInfo),                app.repProcState);............ requestServiceBindingsLocked(r, execInFg);

这个方法在完成scheduleCreateService这个binder调用之后，执行了一个requestServiceBindingsLocked方法；看方法名好像于「绑定服务」有关，它简单地执行了一个遍历然后调用了另外一个方法：

private final boolean requestServiceBindingLocked(ServiceRecord r, IntentBindRecord i,        boolean execInFg, boolean rebind) throws TransactionTooLargeException {    if (r.app == null || r.app.thread == null) {        return false;    }    if ((!i.requested || rebind) && i.apps.size() > 0) {        try {            bumpServiceExecutingLocked(r, execInFg, "bind");            r.app.forceProcessStateUpTo(ActivityManager.PROCESS_STATE_SERVICE);            r.app.thread.scheduleBindService(r, i.intent.getIntent(), rebind,                    r.app.repProcState);        // 不关心，略。。    }    return true;}

可以看到，这里又通过IApplicationThread这个Binder进行了一次IPC调用，我们跟踪ActivityThread类里面的ApplicationThread的scheduleBindService方法，发现这个方法不过通过Handler转发了一次消息，真正的处理代码在handleBindService里面：

rivate void handleBindService(BindServiceData data) {    Service s = mServices.get(data.token);    if (s != null) {        try {            data.intent.setExtrasClassLoader(s.getClassLoader());            data.intent.prepareToEnterProcess();            try {                if (!data.rebind) {                    IBinder binder = s.onBind(data.intent);                    ActivityManagerNative.getDefault().publishService(                            data.token, data.intent, binder);                } else {                    s.onRebind(data.intent);                    ActivityManagerNative.getDefault().serviceDoneExecuting(                            data.token, SERVICE_DONE_EXECUTING_ANON, 0, 0);                }                ensureJitEnabled();            } catch (RemoteException ex) {            }        } catch (Exception e) {        }    }}

我们要Bind的Service终于在这里完成了绑定！绑定之后又通过ActivityManagerNative这个Binder进行一次IPC调用，我们查看AMS的publishService方法，这个方法简单第调用了publishServiceLocked方法，源码如下：

void publishServiceLocked(ServiceRecord r, Intent intent, IBinder service) {    final long origId = Binder.clearCallingIdentity();    try {        if (r != null) {            Intent.FilterComparison filter                    = new Intent.FilterComparison(intent);            IntentBindRecord b = r.bindings.get(filter);            if (b != null && !b.received) {                b.binder = service;                b.requested = true;                b.received = true;                for (int conni=r.connections.size()-1; conni>=0; conni--) {                    ArrayList<ConnectionRecord> clist = r.connections.valueAt(conni);                    for (int i=0; i<clist.size(); i++) {                        ConnectionRecord c = clist.get(i);                        if (!filter.equals(c.binding.intent.intent)) {                            continue;                        }                        try {                            c.conn.connected(r.name, service);                        } catch (Exception e) {                        }                    }                }            }            serviceDoneExecutingLocked(r, mDestroyingServices.contains(r), false);        }    } finally {        Binder.restoreCallingIdentity(origId);    }}

还记得我们之前提到的那个IServiceConnection吗？在bindServiceLocked方法里面，我们把这个IServiceConnection放到了一个ConnectionRecord的List中存放在ServiceRecord里面，这里所做的就是取出已经被Bind的这个Service对应的IServiceConnection对象，然后调用它的connected方法；我们说过，这个IServiceConnection也是一个Binder对象，它的Server端在LoadedApk.ServiceDispatcher里面。

最后提一点，以上我们分析了Service所在进程已经存在的情况，如果Service所在进程不存在，那么会调用startProcessLocked方法创建一个新的进程，并把需要启动的Service放在一个队列里面；创建进程的过程通过Zygote fork出来，进程创建成功之后会调用ActivityThread的main方法，在这个main方法里面间接调用到了AMS的attachApplication方法，在AMS的attachApplication里面会检查刚刚那个待启动Service队列里面的内容，并执行Service的启动操作；之后的启动过程与进程已经存在的情况下相同；可以自行分析。

Service的插件化思路
可以注册一个真正的Service组件ProxyService，让这个ProxyService承载一个真正的Service组件所具备的能力（进程优先级等）；当启动插件的服务比如PluginService的时候，我们统一启动这个ProxyService，当这个ProxyService运行起来之后，再在它的onStartCommand等方法里面进行分发，执行PluginService的onStartCommond等对应的方法；我们把这种方案形象地称为「代理分发技术」

注册代理Service
我们需要一个货真价实的Service组件来承载进程优先级等功能，因此需要在AndroidManifest.xml中声明一个或者多个（用以支持多进程）这样的Sevice：

<service        android:name="com.weishu.upf.service_management.app.ProxyService"        android:process="plugin01"/>

加载Service
我们可以在ProxyService里面把任务转发给真正要启动的插件Service组件，要完成这个过程肯定需要创建一个对应的插件Service对象，比如PluginService；但是通常情况下插件存在与单独的文件之中，正常的方式是无法创建这个PluginService对象的，宿主程序默认的ClassLoader无法加载插件中对应的这个类；所以，要创建这个对应的PluginService对象，必须先完成插件的加载过程，让这个插件中的所有类都可以被正常访问；

public static void patchClassLoader(ClassLoader cl, File apkFile, File optDexFile)        throws IllegalAccessException, NoSuchMethodException, IOException, InvocationTargetException, InstantiationException, NoSuchFieldException {    // 获取 BaseDexClassLoader : pathList    Field pathListField = DexClassLoader.class.getSuperclass().getDeclaredField("pathList");    pathListField.setAccessible(true);    Object pathListObj = pathListField.get(cl);    // 获取 PathList: Element[] dexElements    Field dexElementArray = pathListObj.getClass().getDeclaredField("dexElements");    dexElementArray.setAccessible(true);    Object[] dexElements = (Object[]) dexElementArray.get(pathListObj);    // Element 类型    Class<?> elementClass = dexElements.getClass().getComponentType();    // 创建一个数组, 用来替换原始的数组    Object[] newElements = (Object[]) Array.newInstance(elementClass, dexElements.length + 1);    // 构造插件Element(File file, boolean isDirectory, File zip, DexFile dexFile) 这个构造函数    Constructor<?> constructor = elementClass.getConstructor(File.class, boolean.class, File.class, DexFile.class);    Object o = constructor.newInstance(apkFile, false, apkFile, DexFile.loadDex(apkFile.getCanonicalPath(), optDexFile.getAbsolutePath(), 0));    Object[] toAddElementArray = new Object[] { o };    // 把原始的elements复制进去    System.arraycopy(dexElements, 0, newElements, 0, dexElements.length);    // 插件的那个element复制进去    System.arraycopy(toAddElementArray, 0, newElements, dexElements.length, toAddElementArray.length);    // 替换    dexElementArray.set(pathListObj, newElements);}

 /**     * 解析Apk文件中的 <service>, 并存储起来     * 主要是调用PackageParser类的generateServiceInfo方法     * @param apkFile 插件对应的apk文件     * @throws Exception 解析出错或者反射调用出错, 均会抛出异常     */    public void preLoadServices(File apkFile) throws Exception {        Class<?> packageParserClass = Class.forName("android.content.pm.PackageParser");        Method parsePackageMethod = packageParserClass.getDeclaredMethod("parsePackage", File.class, int.class);        Object packageParser = packageParserClass.newInstance();        // 首先调用parsePackage获取到apk对象对应的Package对象        Object packageObj = parsePackageMethod.invoke(packageParser, apkFile, PackageManager.GET_SERVICES);        // 读取Package对象里面的services字段        // 接下来要做的就是根据这个List<Service> 获取到Service对应的ServiceInfo        Field servicesField = packageObj.getClass().getDeclaredField("services");        List services = (List) servicesField.get(packageObj);        // 调用generateServiceInfo 方法, 把PackageParser.Service转换成ServiceInfo        Class<?> packageParser$ServiceClass = Class.forName("android.content.pm.PackageParser$Service");        Class<?> packageUserStateClass = Class.forName("android.content.pm.PackageUserState");        Class<?> userHandler = Class.forName("android.os.UserHandle");        Method getCallingUserIdMethod = userHandler.getDeclaredMethod("getCallingUserId");        int userId = (Integer) getCallingUserIdMethod.invoke(null);        Object defaultUserState = packageUserStateClass.newInstance();        // 需要调用 android.content.pm.PackageParser#generateActivityInfo(android.content.pm.ActivityInfo, int, android.content.pm.PackageUserState, int)        Method generateReceiverInfo = packageParserClass.getDeclaredMethod("generateServiceInfo",                packageParser$ServiceClass, int.class, packageUserStateClass, int.class);        // 解析出intent对应的Service组件        for (Object service : services) {            ServiceInfo info = (ServiceInfo) generateReceiverInfo.invoke(packageParser, service, 0, defaultUserState, userId);            mServiceInfoMap.put(new ComponentName(info.packageName, info.name), info);        }    }

拦截startService等调用过程
要手动控制Service组件的生命周期，需要拦截startService,stopService等调用，并且把启动插件Service全部重定向为启动ProxyService（保留原始插件Service信息）；这个拦截过程需要Hook ActvityManagerNative，我们对这种技术应该是轻车熟路了

public static void hookActivityManagerNative() throws ClassNotFoundException,        NoSuchMethodException, InvocationTargetException,        IllegalAccessException, NoSuchFieldException {    Class<?> activityManagerNativeClass = Class.forName("android.app.ActivityManagerNative");    Field gDefaultField = activityManagerNativeClass.getDeclaredField("gDefault");    gDefaultField.setAccessible(true);    Object gDefault = gDefaultField.get(null);    // gDefault是一个 android.util.Singleton对象; 我们取出这个单例里面的字段    Class<?> singleton = Class.forName("android.util.Singleton");    Field mInstanceField = singleton.getDeclaredField("mInstance");    mInstanceField.setAccessible(true);    // ActivityManagerNative 的gDefault对象里面原始的 IActivityManager对象    Object rawIActivityManager = mInstanceField.get(gDefault);    // 创建一个这个对象的代理对象, 然后替换这个字段, 让我们的代理对象帮忙干活    Class<?> iActivityManagerInterface = Class.forName("android.app.IActivityManager");    Object proxy = Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(),            new Class<?>[] { iActivityManagerInterface }, new IActivityManagerHandler(rawIActivityManager));    mInstanceField.set(gDefault, proxy);}

我们在收到startService,stopService之后可以进行具体的操作，对于startService来说，就是直接替换启动的插件Service为ProxyService等待后续处理，

if ("startService".equals(method.getName())) {    // API 23:    // public ComponentName startService(IApplicationThread caller, Intent service,    //        String resolvedType, int userId) throws RemoteException    // 找到参数里面的第一个Intent 对象    Pair<Integer, Intent> integerIntentPair = foundFirstIntentOfArgs(args);    Intent newIntent = new Intent();    // 代理Service的包名, 也就是我们自己的包名    String stubPackage = UPFApplication.getContext().getPackageName();    // 这里我们把启动的Service替换为ProxyService, 让ProxyService接收生命周期回调    ComponentName componentName = new ComponentName(stubPackage, ProxyService.class.getName());    newIntent.setComponent(componentName);    // 把我们原始要启动的TargetService先存起来    newIntent.putExtra(AMSHookHelper.EXTRA_TARGET_INTENT, integerIntentPair.second);    // 替换掉Intent, 达到欺骗AMS的目的    args[integerIntentPair.first] = newIntent;    Log.v(TAG, "hook method startService success");    return method.invoke(mBase, args);}

分发Service
Hook ActivityManagerNative之后，所有的插件Service的启动都被重定向了到了我们注册的ProxyService，这样可以保证我们的插件Service有一个真正的Service组件作为宿主；但是要执行特定插件Service的任务，我们必须把这个任务分发到真正要启动的Service上去；以onStart为例，在启动ProxyService之后，会收到ProxyService的onStart回调，我们可以在这个方法里面把具体的任务交给原始要启动的插件Service组件：

  @Override    public void onStart(Intent intent, int startId) {        Log.d(TAG, "onStart() called with " + "intent = [" + intent + "], startId = [" + startId + "]");        // 分发Service        ServiceManager.getInstance().onStart(intent, startId);        super.onStart(intent, startId);    }

匹配过程
上文中我们把启动插件Service重定向为启动ProxyService，现在ProxyService已经启动，因此必须把控制权交回原始的PluginService；在加载插件的时候，我们存储了插件中所有的Service组件的信息，因此，只需要根据Intent里面的Component信息就可以取出对应的PluginService。

private ServiceInfo selectPluginService(Intent pluginIntent) {    for (ComponentName componentName : mServiceInfoMap.keySet()) {        if (componentName.equals(pluginIntent.getComponent())) {            return mServiceInfoMap.get(componentName);        }    }    return null;}

创建以及分发
可以看到，系统也是通过反射创建出了对应的Service对象，然后也创建了对应的Context，并给Service注入了活力。如果我们模拟系统创建Context这个过程，势必需要进行一系列反射调用，那么我们何不直接反射handleCreateService方法呢？

现在我们已经创建出了对应的PluginService，并且拥有至关重要的Context对象；接下来就可以把消息分发给原始的PluginService组件了，这个分发的过程很简单，直接执行消息对应的回调(onStart, onDestroy等）即可；因此，完整的startService分发过程如下：

public void onStart(Intent proxyIntent, int startId) {    Intent targetIntent = proxyIntent.getParcelableExtra(AMSHookHelper.EXTRA_TARGET_INTENT);    ServiceInfo serviceInfo = selectPluginService(targetIntent);    if (serviceInfo == null) {        Log.w(TAG, "can not found service : " + targetIntent.getComponent());        return;    }    try {        if (!mServiceMap.containsKey(serviceInfo.name)) {            // service还不存在, 先创建            proxyCreateService(serviceInfo);        }        Service service = mServiceMap.get(serviceInfo.name);        service.onStart(targetIntent, startId);    } catch (Exception e) {        e.printStackTrace();    }}

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配置文件

<manifest xmlns:android="http://schemas.android.com/apk/res/android"          package="com.weishu.upf.service_management.app">    <application            android:allowBackup="true"            android:name="com.weishu.upf.service_management.app.UPFApplication"            android:label="@string/app_name"            android:icon="@mipmap/ic_launcher">        <activity android:name="com.weishu.upf.service_management.app.MainActivity">            <intent-filter>                <action android:name="android.intent.action.MAIN"/>                <category android:name="android.intent.category.LAUNCHER"/>            </intent-filter>        </activity>        <service                android:name="com.weishu.upf.service_management.app.ProxyService"                android:process="plugin01"/>    </application></manifest>

UPFApplication

package com.weishu.upf.service_management.app;import java.io.File;import android.app.Application;import android.content.Context;import com.weishu.upf.service_management.app.hook.AMSHookHelper;import com.weishu.upf.service_management.app.hook.BaseDexClassLoaderHookHelper;/** * 这个类只是为了方便获取全局Context的. */public class UPFApplication extends Application {    private static Context sContext;    @Override    protected void attachBaseContext(Context base) {        super.attachBaseContext(base);        sContext = base;        try {            // 拦截startService, stopService等操作            AMSHookHelper.hookActivityManagerNative();            Utils.extractAssets(base, "test.jar");            File apkFile = getFileStreamPath("test.jar");            File odexFile = getFileStreamPath("test.odex");            // Hook ClassLoader, 让插件中的类能够被成功加载            BaseDexClassLoaderHookHelper.patchClassLoader(getClassLoader(), apkFile, odexFile);            // 解析插件中的Service组件            ServiceManager.getInstance().preLoadServices(apkFile);        } catch (Exception e) {            throw new RuntimeException("hook failed");        }    }    public static Context getContext() {        return sContext;    }}

AMSHookHelper.hookActivityManagerNative();
AMSHookHelper

package com.weishu.upf.service_management.app.hook;import java.lang.reflect.Field;import java.lang.reflect.InvocationTargetException;import java.lang.reflect.Proxy;public class AMSHookHelper {    public static final String EXTRA_TARGET_INTENT = "extra_target_intent";    /**     * Hook AMS     * <p/>     * 主要完成的操作是  "把真正要启动的Activity临时替换为在AndroidManifest.xml中声明的替身Activity"     * <p/>     * 进而骗过AMS     *     * @throws ClassNotFoundException     * @throws NoSuchMethodException     * @throws InvocationTargetException     * @throws IllegalAccessException     * @throws NoSuchFieldException     */    public static void hookActivityManagerNative() throws ClassNotFoundException,            NoSuchMethodException, InvocationTargetException,            IllegalAccessException, NoSuchFieldException {        //        17package android.util;        //        18        //        19/**        //         20 * Singleton helper class for lazily initialization.        //         21 *        //         22 * Modeled after frameworks/base/include/utils/Singleton.h        //         23 *        //         24 * @hide        //         25 */        //        26public abstract class Singleton<T> {        //            27    private T mInstance;        //            28        //                    29    protected abstract T create();        //            30        //                    31    public final T get() {        //                32        synchronized (this) {        //                    33            if (mInstance == null) {        //                        34                mInstance = create();        //                        35            }        //                    36            return mInstance;        //                    37        }        //                38    }        //            39}        //        40        Class<?> activityManagerNativeClass = Class.forName("android.app.ActivityManagerNative");        Field gDefaultField = activityManagerNativeClass.getDeclaredField("gDefault");        gDefaultField.setAccessible(true);        Object gDefault = gDefaultField.get(null);        // gDefault是一个 android.util.Singleton对象; 我们取出这个单例里面的字段        Class<?> singleton = Class.forName("android.util.Singleton");        Field mInstanceField = singleton.getDeclaredField("mInstance");        mInstanceField.setAccessible(true);        // ActivityManagerNative 的gDefault对象里面原始的 IActivityManager对象        Object rawIActivityManager = mInstanceField.get(gDefault);        // 创建一个这个对象的代理对象, 然后替换这个字段, 让我们的代理对象帮忙干活        Class<?> iActivityManagerInterface = Class.forName("android.app.IActivityManager");        Object proxy = Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(),                new Class<?>[] { iActivityManagerInterface }, new IActivityManagerHandler(rawIActivityManager));        mInstanceField.set(gDefault, proxy);    }}

IActivityManagerHandler

package com.weishu.upf.service_management.app.hook;import java.lang.reflect.InvocationHandler;import java.lang.reflect.Method;import android.content.ComponentName;import android.content.Intent;import android.text.TextUtils;import android.util.Log;import android.util.Pair;import com.weishu.upf.service_management.app.ProxyService;import com.weishu.upf.service_management.app.ServiceManager;import com.weishu.upf.service_management.app.UPFApplication;/** * @author weishu * @dete 16/1/7. *//* package */ class IActivityManagerHandler implements InvocationHandler {    private static final String TAG = "IActivityManagerHandler";    Object mBase;    public IActivityManagerHandler(Object base) {        mBase = base;    }    @Override    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {        if ("startService".equals(method.getName())) {            // 只拦截这个方法            // API 23:            // public ComponentName startService(IApplicationThread caller, Intent service,            //        String resolvedType, int userId) throws RemoteException            // 找到参数里面的第一个Intent 对象            Pair<Integer, Intent> integerIntentPair = foundFirstIntentOfArgs(args);            Intent newIntent = new Intent();            // 代理Service的包名, 也就是我们自己的包名            String stubPackage = UPFApplication.getContext().getPackageName();            // 这里我们把启动的Service替换为ProxyService, 让ProxyService接收生命周期回调            ComponentName componentName = new ComponentName(stubPackage, ProxyService.class.getName());            newIntent.setComponent(componentName);            // 把我们原始要启动的TargetService先存起来            newIntent.putExtra(AMSHookHelper.EXTRA_TARGET_INTENT, integerIntentPair.second);            // 替换掉Intent, 达到欺骗AMS的目的            args[integerIntentPair.first] = newIntent;            Log.v(TAG, "hook method startService success");            return method.invoke(mBase, args);        }        //     public int stopService(IApplicationThread caller, Intent service,        // String resolvedType, int userId) throws RemoteException        if ("stopService".equals(method.getName())) {            Intent raw = foundFirstIntentOfArgs(args).second;            if (!TextUtils.equals(UPFApplication.getContext().getPackageName(), raw.getComponent().getPackageName())) {                // 插件的intent才做hook                Log.v(TAG, "hook method stopService success");                return ServiceManager.getInstance().stopService(raw);            }        }        return method.invoke(mBase, args);    }    private Pair<Integer, Intent> foundFirstIntentOfArgs(Object... args) {        int index = 0;        for (int i = 0; i < args.length; i++) {            if (args[i] instanceof Intent) {                index = i;                break;            }        }        return Pair.create(index, (Intent) args[index]);    }}

Utils.extractAssets(base, “test.jar”);
Utils

package com.weishu.upf.service_management.app;import java.io.Closeable;import java.io.File;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import android.content.Context;import android.content.res.AssetManager;/** * @author weishu * @date 16/3/29 */public class Utils {    /**     * 把Assets里面得文件复制到 /data/data/files 目录下     *     * @param context     * @param sourceName     */    public static void extractAssets(Context context, String sourceName) {        AssetManager am = context.getAssets();        InputStream is = null;        FileOutputStream fos = null;        try {            is = am.open(sourceName);            File extractFile = context.getFileStreamPath(sourceName);            fos = new FileOutputStream(extractFile);            byte[] buffer = new byte[1024];            int count = 0;            while ((count = is.read(buffer)) > 0) {                fos.write(buffer, 0, count);            }            fos.flush();        } catch (IOException e) {            e.printStackTrace();        } finally {            closeSilently(is);            closeSilently(fos);        }    }    // --------------------------------------------------------------------------    private static void closeSilently(Closeable closeable) {        if (closeable == null) {            return;        }        try {            closeable.close();        } catch (Throwable e) {            // ignore        }    }    private static File sBaseDir;}

BaseDexClassLoaderHookHelper.patchClassLoader(getClassLoader(), apkFile, odexFile);
BaseDexClassLoaderHookHelper

package com.weishu.upf.service_management.app.hook;import java.io.File;import java.io.IOException;import java.lang.reflect.Array;import java.lang.reflect.Constructor;import java.lang.reflect.Field;import java.lang.reflect.InvocationTargetException;import dalvik.system.DexClassLoader;import dalvik.system.DexFile;/** * 由于应用程序使用的ClassLoader为PathClassLoader * 最终继承自 BaseDexClassLoader * 查看源码得知,这个BaseDexClassLoader加载代码根据一个叫做 * dexElements的数组进行, 因此我们把包含代码的dex文件插入这个数组 * 系统的classLoader就能帮助我们找到这个类 * * 这个类用来进行对于BaseDexClassLoader的Hook * 类名太长, 不要吐槽. * @author weishu * @date 16/3/28 */public final class BaseDexClassLoaderHookHelper {    public static void patchClassLoader(ClassLoader cl, File apkFile, File optDexFile)            throws IllegalAccessException, NoSuchMethodException, IOException, InvocationTargetException, InstantiationException, NoSuchFieldException {        // 获取 BaseDexClassLoader : pathList        Field pathListField = DexClassLoader.class.getSuperclass().getDeclaredField("pathList");        pathListField.setAccessible(true);        Object pathListObj = pathListField.get(cl);        // 获取 PathList: Element[] dexElements        Field dexElementArray = pathListObj.getClass().getDeclaredField("dexElements");        dexElementArray.setAccessible(true);        Object[] dexElements = (Object[]) dexElementArray.get(pathListObj);        // Element 类型        Class<?> elementClass = dexElements.getClass().getComponentType();        // 创建一个数组, 用来替换原始的数组        Object[] newElements = (Object[]) Array.newInstance(elementClass, dexElements.length + 1);        // 构造插件Element(File file, boolean isDirectory, File zip, DexFile dexFile) 这个构造函数        Constructor<?> constructor = elementClass.getConstructor(File.class, boolean.class, File.class, DexFile.class);        Object o = constructor.newInstance(apkFile, false, apkFile, DexFile.loadDex(apkFile.getCanonicalPath(), optDexFile.getAbsolutePath(), 0));        Object[] toAddElementArray = new Object[] { o };        // 把原始的elements复制进去        System.arraycopy(dexElements, 0, newElements, 0, dexElements.length);        // 插件的那个element复制进去        System.arraycopy(toAddElementArray, 0, newElements, dexElements.length, toAddElementArray.length);        // 替换        dexElementArray.set(pathListObj, newElements);    }}

MainActivity

package com.weishu.upf.service_management.app;import android.app.Activity;import android.content.ComponentName;import android.content.Intent;import android.os.Bundle;import android.view.View;/** * @author weishu * @date 16/5/9 */public class MainActivity extends Activity implements View.OnClickListener {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        findViewById(R.id.startService1).setOnClickListener(this);        findViewById(R.id.startService2).setOnClickListener(this);        findViewById(R.id.stopService1).setOnClickListener(this);        findViewById(R.id.stopService2).setOnClickListener(this);    }    @Override    public void onClick(View v) {        switch (v.getId()) {            case R.id.startService1:                startService(new Intent().setComponent(                        new ComponentName("com.weishu.upf.demo.app2", "com.weishu.upf.demo.app2.TargetService1")));                break;            case R.id.startService2:                startService(new Intent().setComponent(                        new ComponentName("com.weishu.upf.demo.app2", "com.weishu.upf.demo.app2.TargetService2")));                break;            case R.id.stopService1:                stopService(new Intent().setComponent(                        new ComponentName("com.weishu.upf.demo.app2", "com.weishu.upf.demo.app2.TargetService1")));                break;            case R.id.stopService2:                stopService(new Intent().setComponent(                        new ComponentName("com.weishu.upf.demo.app2", "com.weishu.upf.demo.app2.TargetService2")));                break;        }    }}

ProxyService

package com.weishu.upf.service_management.app;import android.app.Service;import android.content.Intent;import android.os.IBinder;import android.util.Log;/** * @author weishu * @date 16/5/10 */public class ProxyService extends Service {    private static final String TAG = "ProxyService";    @Override    public void onCreate() {        Log.d(TAG, "onCreate() called");        super.onCreate();    }    @Override    public void onStart(Intent intent, int startId) {        Log.d(TAG, "onStart() called with " + "intent = [" + intent + "], startId = [" + startId + "]");        // 分发Service        ServiceManager.getInstance().onStart(intent, startId);        super.onStart(intent, startId);    }    @Override    public IBinder onBind(Intent intent) {        // TODO: 16/5/11 bindService实现        return null;    }    @Override    public void onDestroy() {        Log.d(TAG, "onDestroy() called");        super.onDestroy();    }}

ServiceManager

package com.weishu.upf.service_management.app;import java.io.File;import java.lang.reflect.Constructor;import java.lang.reflect.Field;import java.lang.reflect.Method;import java.util.HashMap;import java.util.List;import java.util.Map;import android.app.Service;import android.content.ComponentName;import android.content.Context;import android.content.Intent;import android.content.pm.PackageManager;import android.content.pm.ServiceInfo;import android.os.Binder;import android.os.IBinder;import android.util.Log;import com.weishu.upf.service_management.app.hook.AMSHookHelper;/** * @author weishu * @date 16/5/10 */public final class ServiceManager {    private static final String TAG = "ServiceManager";    private static volatile ServiceManager sInstance;    private Map<String, Service> mServiceMap = new HashMap<String, Service>();    // 存储插件的Service信息    private Map<ComponentName, ServiceInfo> mServiceInfoMap = new HashMap<ComponentName, ServiceInfo>();    public synchronized static ServiceManager getInstance() {        if (sInstance == null) {            sInstance = new ServiceManager();        }        return sInstance;    }    /**     * 启动某个插件Service; 如果Service还没有启动, 那么会创建新的插件Service     * @param proxyIntent     * @param startId     */    public void onStart(Intent proxyIntent, int startId) {        Intent targetIntent = proxyIntent.getParcelableExtra(AMSHookHelper.EXTRA_TARGET_INTENT);        ServiceInfo serviceInfo = selectPluginService(targetIntent);        if (serviceInfo == null) {            Log.w(TAG, "can not found service : " + targetIntent.getComponent());            return;        }        try {            if (!mServiceMap.containsKey(serviceInfo.name)) {                // service还不存在, 先创建                proxyCreateService(serviceInfo);            }            Service service = mServiceMap.get(serviceInfo.name);            service.onStart(targetIntent, startId);        } catch (Exception e) {            e.printStackTrace();        }    }    /**     * 停止某个插件Service, 当全部的插件Service都停止之后, ProxyService也会停止     * @param targetIntent     * @return     */    public int stopService(Intent targetIntent) {        ServiceInfo serviceInfo = selectPluginService(targetIntent);        if (serviceInfo == null) {            Log.w(TAG, "can not found service: " + targetIntent.getComponent());            return 0;        }        Service service = mServiceMap.get(serviceInfo.name);        if (service == null) {            Log.w(TAG, "can not runnning, are you stopped it multi-times?");            return 0;        }        service.onDestroy();        mServiceMap.remove(serviceInfo.name);        if (mServiceMap.isEmpty()) {            // 没有Service了, 这个没有必要存在了            Log.d(TAG, "service all stopped, stop proxy");            Context appContext = UPFApplication.getContext();            appContext.stopService(new Intent().setComponent(new ComponentName(appContext.getPackageName(), ProxyService.class.getName())));        }        return 1;    }    /**     * 选择匹配的ServiceInfo     * @param pluginIntent 插件的Intent     * @return     */    private ServiceInfo selectPluginService(Intent pluginIntent) {        for (ComponentName componentName : mServiceInfoMap.keySet()) {            if (componentName.equals(pluginIntent.getComponent())) {                return mServiceInfoMap.get(componentName);            }        }        return null;    }    /**     * 通过ActivityThread的handleCreateService方法创建出Service对象     * @param serviceInfo 插件的ServiceInfo     * @throws Exception     */    private void proxyCreateService(ServiceInfo serviceInfo) throws Exception {        IBinder token = new Binder();        // 创建CreateServiceData对象, 用来传递给ActivityThread的handleCreateService 当作参数        Class<?> createServiceDataClass = Class.forName("android.app.ActivityThread$CreateServiceData");        Constructor<?> constructor  = createServiceDataClass.getDeclaredConstructor();        constructor.setAccessible(true);        Object createServiceData = constructor.newInstance();        // 写入我们创建的createServiceData的token字段, ActivityThread的handleCreateService用这个作为key存储Service        Field tokenField = createServiceDataClass.getDeclaredField("token");        tokenField.setAccessible(true);        tokenField.set(createServiceData, token);        // 写入info对象        // 这个修改是为了loadClass的时候, LoadedApk会是主程序的ClassLoader, 我们选择Hook BaseDexClassLoader的方式加载插件        serviceInfo.applicationInfo.packageName = UPFApplication.getContext().getPackageName();        Field infoField = createServiceDataClass.getDeclaredField("info");        infoField.setAccessible(true);        infoField.set(createServiceData, serviceInfo);        // 写入compatInfo字段        // 获取默认的compatibility配置        Class<?> compatibilityClass = Class.forName("android.content.res.CompatibilityInfo");        Field defaultCompatibilityField = compatibilityClass.getDeclaredField("DEFAULT_COMPATIBILITY_INFO");        Object defaultCompatibility = defaultCompatibilityField.get(null);        Field compatInfoField = createServiceDataClass.getDeclaredField("compatInfo");        compatInfoField.setAccessible(true);        compatInfoField.set(createServiceData, defaultCompatibility);        Class<?> activityThreadClass = Class.forName("android.app.ActivityThread");        Method currentActivityThreadMethod = activityThreadClass.getDeclaredMethod("currentActivityThread");        Object currentActivityThread = currentActivityThreadMethod.invoke(null);        // private void handleCreateService(CreateServiceData data) {        Method handleCreateServiceMethod = activityThreadClass.getDeclaredMethod("handleCreateService", createServiceDataClass);        handleCreateServiceMethod.setAccessible(true);        handleCreateServiceMethod.invoke(currentActivityThread, createServiceData);        // handleCreateService创建出来的Service对象并没有返回, 而是存储在ActivityThread的mServices字段里面, 这里我们手动把它取出来        Field mServicesField = activityThreadClass.getDeclaredField("mServices");        mServicesField.setAccessible(true);        Map mServices = (Map) mServicesField.get(currentActivityThread);        Service service = (Service) mServices.get(token);        // 获取到之后, 移除这个service, 我们只是借花献佛        mServices.remove(token);        // 将此Service存储起来        mServiceMap.put(serviceInfo.name, service);    }    /**     * 解析Apk文件中的 <service>, 并存储起来     * 主要是调用PackageParser类的generateServiceInfo方法     * @param apkFile 插件对应的apk文件     * @throws Exception 解析出错或者反射调用出错, 均会抛出异常     */    public void preLoadServices(File apkFile) throws Exception {        Class<?> packageParserClass = Class.forName("android.content.pm.PackageParser");        Method parsePackageMethod = packageParserClass.getDeclaredMethod("parsePackage", File.class, int.class);        Object packageParser = packageParserClass.newInstance();        // 首先调用parsePackage获取到apk对象对应的Package对象        Object packageObj = parsePackageMethod.invoke(packageParser, apkFile, PackageManager.GET_SERVICES);        // 读取Package对象里面的services字段        // 接下来要做的就是根据这个List<Service> 获取到Service对应的ServiceInfo        Field servicesField = packageObj.getClass().getDeclaredField("services");        List services = (List) servicesField.get(packageObj);        // 调用generateServiceInfo 方法, 把PackageParser.Service转换成ServiceInfo        Class<?> packageParser$ServiceClass = Class.forName("android.content.pm.PackageParser$Service");        Class<?> packageUserStateClass = Class.forName("android.content.pm.PackageUserState");        Class<?> userHandler = Class.forName("android.os.UserHandle");        Method getCallingUserIdMethod = userHandler.getDeclaredMethod("getCallingUserId");        int userId = (Integer) getCallingUserIdMethod.invoke(null);        Object defaultUserState = packageUserStateClass.newInstance();        // 需要调用 android.content.pm.PackageParser#generateActivityInfo(android.content.pm.ActivityInfo, int, android.content.pm.PackageUserState, int)        Method generateReceiverInfo = packageParserClass.getDeclaredMethod("generateServiceInfo",                packageParser$ServiceClass, int.class, packageUserStateClass, int.class);        // 解析出intent对应的Service组件        for (Object service : services) {            ServiceInfo info = (ServiceInfo) generateReceiverInfo.invoke(packageParser, service, 0, defaultUserState, userId);            mServiceInfoMap.put(new ComponentName(info.packageName, info.name), info);        }    }}