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(); }}、、、、、、、、、、、、、、、、、、、、、代码区、、、、、、、、、、、、、、、、、、、、、、、 
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); } }}新闻热点
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