Android 插件化处理方案详解

public ActivityResult execStartActivity(Context who, IBinder contextThread, IBinder token, Activity target,
                    Intent intent, int requestCode, Bundle options) {

  //如果启动的是插件的activity组件，这里面将会被替换成宿主预先声明的
  PluginIntentResolver.resolveActivity(intent);
  return hackInstrumentation.execStartActivity(who, contextThread, token, target, intent, requestCode, ptions);
}

@Override
public Activity newActivity(ClassLoader cl, String className, Intent intent) throws InstantiationException,
    IllegalAccessException, ClassNotFoundException {

  ClassLoader orignalCl = cl;
  String orginalClassName = className;
  String orignalIntent = intent.toString();
  if (ProcessUtil.isPluginProcess()) {
    // 将PluginStubActivity替换成插件中的activity
    if (PluginManagerHelper.isStub(className)) {
      String action = intent.getAction();
      if (action != null && action.contains(PluginIntentResolver.CLASS_SEPARATOR)) {
        String[] targetClassName = action.split(PluginIntentResolver.CLASS_SEPARATOR);
        String pluginClassName = targetClassName[0];
        final String pid = intent.getStringExtra(PluginIntentResolver.INTENT_EXTRA_PID).trim();
        PluginDescriptor pluginDescriptor = TextUtils.isEmpty(pid) ? PluginManagerHelper.getPluginDescriptorByClassName(pluginClassName) : PluginManagerHelper.getPluginDescriptorByPluginId(pid);
        Class<?> clazz = PluginLoader.loadPluginClassByName(pluginDescriptor, pluginClassName);
        if (clazz != null) {
          className = pluginClassName;
          cl = clazz.getClassLoader();
          intent.setExtrasClassLoader(cl);
          if (targetClassName.length > 1) {
            // 之前为了传递classNae，intent的action被修改过
            // 这里再把Action还原到原始的Action
            intent.setAction(targetClassName[1]);
          } else {
            intent.setAction(null);
          }
          // 添加一个标记符
          intent.addCategory(RELAUNCH_FLAG + className);
        } else {
          throw new ClassNotFoundException("pluginClassName : " + pluginClassName, new Throwable());
        }
      } else if (PluginManagerHelper.isExact(className, PluginDescriptor.ACTIVITY)) {
        // 这个逻辑是为了支持外部app唤起配置了stub_exact的插件Activity
        PluginDescriptor pluginDescriptor = PluginManagerHelper.getPluginDescriptorByClassName(className);
        if (pluginDescriptor != null) {
          boolean isRunning = PluginLauncher.instance().isRunning(pluginDescriptor.getPackageName());
          if (!isRunning) {
            return waitForLoading(pluginDescriptor);
          }
        }
        Class<?> clazz = PluginLoader.loadPluginClassByName(pluginDescriptor, className);
        if (clazz != null) {
          cl = clazz.getClassLoader();
        } else {
          throw new ClassNotFoundException("className : " + className, new Throwable());
        }
      } else {
        // 进入这个分支可能是因为activity重启了，比如横竖屏切换，由于上面的分支已经把Action还原到原始到Action了
        // 这里只能通过之前添加的标记符来查找className
        boolean found = false;
        Set<String> category = intent.getCategories();
        if (category != null) {
          Iterator<String> itr = category.iterator();
          while (itr.hasNext()) {
            String cate = itr.next();
            if (cate.startsWith(RELAUNCH_FLAG)) {
              className = cate.replace(RELAUNCH_FLAG, "");
              PluginDescriptor pluginDescriptor = PluginManagerHelper.getPluginDescriptorByClassName(className);
              if (pluginDescriptor != null) {
                boolean isRunning = PluginLauncher.instance().isRunning(
                    pluginDescriptor.getPackageName());
                if (!isRunning) {
                  return waitForLoading(pluginDescriptor);
                }
              }
              Class<?> clazz = PluginLoader.loadPluginClassByName(pluginDescriptor, className);
              cl = clazz.getClassLoader();
              found = true;
              break;
            }
          }
        }
        if (!found) {
          throw new ClassNotFoundException(
              "className : " + className + ", intent : " + intent.toString(), new Throwable());
        }
      }
    } else {
      if (cl instanceof PluginClassLoader) {
        PluginIntentResolver.resolveActivity(intent);
      } else {
        // Do Nothing
      }
    }
  }
  try {
    Activity activity = super.newActivity(cl, className, intent);
    if (activity instanceof PluginContainer) {
      ((PluginContainer) activity).setPluginId(intent.getStringExtra(PluginContainer.FRAGMENT_PLUGIN_ID));
    }
    return activity;
  } catch (ClassNotFoundException e) {
    // 收集状态，便于异常分析
    throw new ClassNotFoundException(" orignalCl : " + orignalCl.toString() + ", orginalClassName : "
        + orginalClassName + ", orignalIntent : " + orignalIntent + ", currentCl : " + cl.toString()
        + ", currentClassName : " + className + ", currentIntent : " + intent.toString() + ", process : "
        + ProcessUtil.isPluginProcess() + ", isStubActivity : "
        + PluginManagerHelper.isStub(orginalClassName) + ", isExact : "
        + PluginManagerHelper.isExact(orginalClassName, PluginDescriptor.ACTIVITY), e);
  }
}

@Override
public void callActivityOnCreate(Activity activity, Bundle icicle) {
  PluginInjector.injectActivityContext(activity);

  Intent intent = activity.getIntent();

  if (intent != null) {
    intent.setExtrasClassLoader(activity.getClassLoader());
  }
  if (icicle != null) {
    icicle.setClassLoader(activity.getClassLoader());
  }
  if (ProcessUtil.isPluginProcess()) {
    installPluginViewFactory(activity);
    if (activity instanceof WaitForLoadingPluginActivity) {
      // NOTHING
    } else {
    }
    if (activity.isChild()) {
      // 修正TabActivity中的Activity的ContextImpl的packageName
      Context base = activity.getBaseContext();
      while (base instanceof ContextWrapper) {
        base = ((ContextWrapper) base).getBaseContext();
      }
      if (HackContextImpl.instanceOf(base)) {
        HackContextImpl impl = new HackContextImpl(base);
        String packageName = PluginLoader.getApplication().getPackageName();
        // String packageName1 = activity.getPackageName();
        impl.setBasePackageName(packageName);
        impl.setOpPackageName(packageName);
      }
    }
  }
  super.callActivityOnCreate(activity, icicle);
  monitor.onActivityCreate(activity);
}