Android精准发送Event事件响应框架(解决滥用Event

2020-08-20  本文已影响0人  小麦子V587

在Android项目中,相信Eventbus大家已经很熟悉了,Eventbus是一个支持跨Module的事件发送响应框架,但是随着项目的不断扩大 以及多人团队的开发,渐渐的会出现一个不大和谐的情况,就是有一部分开发童鞋由于一些特定的业务场景,会经常复用组内其他成员的event事件,久而久之 就会出现多个eventbus事件发送 多个场景同时接收,某天也许你会发现一个很奇怪的bug,但怎么也找不到原因,最后会发现是之前的童鞋滥用的eventbus导致,这类的bug往往要浪费很长时间,而且有的event事件也找不到post源头和handle的接受者。
应对这种情况,本人开发了点对点的开发框架,大体保持了EventBus的用法,以下是使用方式:
接收:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    PointBus.getDefault().register(this);
    setContentView(R.layout.activity_main);
}

public void onTestClick(View view){
    Intent intent = new Intent(this, TestActivity.class);
    startActivity(intent);
}

@PointSubscribe(threadMode = ThreadMode.MAIN)
public void handleEvent(TestEvent testEvent) {
    Toast.makeText(this,testEvent.msg,Toast.LENGTH_LONG).show();
}

@Override
protected void onDestroy() {
    super.onDestroy();
    PointBus.getDefault().unRegister(this);
}

发送:

  public void testPost() {
    PointBus.getDefault().post(this, new TestEvent("from TestActivity"), "com.fly.ui.test.MainActivity");
}

这里的com.fly.ui.test.MainActivity就是上述接收事件的Activity 就算其他的Actvity或者Fragment 处理的相同的event 也接收不到 你可以指定你的event 往哪发松

下面是实现原理,大体原理还是使用的APT 这里对APT不熟悉的童鞋可以找些基础的文章学习一下 很容易上手 下面贴一下process部分关键的代码

     TypeElement classElement = (TypeElement) method.getEnclosingElement();
                VariableElement param = method.getParameters().get(0);
                TypeMirror typeMirror = getParamTypeMirror(param, messager);
                String className = classElement.getSimpleName().toString();

                if (element instanceof ExecutableElement) {
                  PointSubscribe bindView = element.getAnnotation(PointSubscribe.class);
                  String threadMode = bindView.threadMode().name();             
                  ExecutableElement method = (ExecutableElement) element;

这样明白了注解标注的方法对应的类的全名和event类全名 所有的信息都存储在缓存列表中
最后创建一个Java文件

 Writer writer = jfo.openWriter();
        writer.write("package " + packName + ";");
        writer.write("\n\n");
        writer.write("import com.fly.bus.SubscribeImpl;");
        writer.write("\n");
        writer.write("import com.fly.bus.SubscribeInfo;");
        writer.write("\n");
        writer.write("import java.util.ArrayList;");
        writer.write("\n");
        writer.write("import java.util.HashMap;");
        writer.write("\n");
        writer.write("import java.util.List;");
        writer.write("\n");
        writer.write("public class " + newClassName + " implements SubscribeImpl{\n\n");
        writer.write("      public static HashMap<String,List<SubscribeInfo>> subscribeInfoMap;\n");
        writer.write("      public static List<SubscribeInfo> subscribeInfoList;\n");
        writer.write("      static {\n");
        writer.write("          subscribeInfoMap = new HashMap<>();\n");
        initSubscribeInfo(writer, hashMap);
        writer.write("      }\n");
        writer.write("      public static void initSubscribeInfo(String methodName,String   eventName,String threadMode){\n");
        writer.write("          subscribeInfoList.add(new SubscribeInfo(methodName,eventName,threadMode)); \n");
        writer.write("      }\n");
        writer.write("      @Override\n");
        writer.write("      public HashMap<String, List<SubscribeInfo>> getSubscribeInfo(){\n");
        writer.write("              return subscribeInfoMap;\n");
        writer.write("      }\n");
        writer.write("\n\n");
        writer.write("}\n");
        writer.flush();
        writer.close();

private void initSubscribeInfo(Writer writer, HashMap<String, List<SimpleSubscribeInfo>> hashMap) {
    try {
        for (String className : hashMap.keySet()) {
            writer.write("          subscribeInfoList = new ArrayList<>();\n");
            List<SimpleSubscribeInfo> infoList = hashMap.get(className);
            if (infoList == null || infoList.size() == 0) {
                continue;
            }
            for (SimpleSubscribeInfo info : infoList) {
                String methodName = info.getMethodName();
                String eventName = info.getEventName();
                String threadMode = info.getThreadMode();
                writer.write("          initSubscribeInfo(" + "\"" + methodName + "\"" + "," + "\"" + eventName + "\"" + "," + "\"" + threadMode + "\"" + "); \n");
            }
            writer.write("          subscribeInfoMap.put(" + "\"" + className + "\"" + ",subscribeInfoList);\n");
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

总结:将所有注解的方法对应的类和参数名 在编译器 利用AbstractProcessor保存在一个在编译器生成的Hashmap里,当你post的时候 以你的目标类的全名(com.fly.ui.test.MainActivity)作为key去寻找出对应的value,value里保存着event类全名和方法名 以及要处理事件的线程,然后就invoke method即可

最后附上github链接:https://github.com/tmacfly/PointBusMaster
转发请标明出处 万分感谢

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