Andoid 总线设计 (三)

我会带着你远行 2022-07-20 12:16 107阅读 0赞

具体的代码设计：  
![这里写图片描述][20160724175319589]

标记注解 用于执行方法上面  
@Retention(RetentionPolicy.RUNTIME)  
@Target(ElementType.METHOD)  
public @interface **Subscriber** \{  
SubscriberType type();  
\}

标记执行类型 同步或者异步  
public enum **SubscriberType** \{  
ASYN, SYNC;  
\}

![这里写图片描述][20160724175950624]

**SubscribeMethod 保存目标函数的一个类：**  
里面有：  
//执行对象  
private Object object;  
// 方法  
private Method method;  
// 参数 (只支持一个参数的方法)  
private Class<> parameters;  
//执行类型  
private SubscriberType subscriberType;

省 get set

**DistributeHandler 是一个分发接口**

AsynDistributeHandler 异步分发实现。  
SyncDistributeHandler 同步分发实现。

public interface **DistributeHandler** \{  
void handEvent(Object parameter);  
\}

--------------------

public class **AsynDistributeHandler** implements DistributeHandler \{  
public AsynDistributeHandler(SubscribeMethod subscribeMethod) \{  
this.subscribeMethod = subscribeMethod;  
\}

private SubscribeMethod subscribeMethod = null;
    
    @Override
    public void handEvent(final Object parameter) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                ReflectionHelper.invokeSubscribeMethod(subscribeMethod, parameter);
            }
        }).start();
    }

--------------------

public class SyncDistributeHandler implements **DistributeHandler** \{

private SubscribeMethod subscribeMethod = null;
    
    public SyncDistributeHandler(SubscribeMethod subscribeMethod) {
        this.subscribeMethod = subscribeMethod;
    }
    
    @Override
    public void handEvent(Object parameter) {
        ReflectionHelper.invokeSubscribeMethod(subscribeMethod, parameter);
    }

分发处理 管理类  
DistributeManeger 管理事件的分发

public class **DistributeManeger** \{  
private DistributeHandler distributeHandler;

/**
     * 分发事件
     *
     * @param parameter
     */
    public void post(Object parameter) {
        List<SubscribeMethod> subscribeMethods = ReflectionHelper.getTypeSubscribeMethods(parameter, EventBus.getInstance().getSubscribeMethodList());
        for (SubscribeMethod subscribeMethod : subscribeMethods) {
            if (subscribeMethod.getSubscriberType().equals(SubscriberType.ASYN)) {
                distributeHandler = new AsynDistributeHandler(subscribeMethod);
                distributeHandler.handEvent(parameter);
            } else if (subscribeMethod.getSubscriberType().equals(SubscriberType.SYNC)) {
                distributeHandler = new SyncDistributeHandler(subscribeMethod);
                distributeHandler.handEvent(parameter);
            }
        }
    }
    
    /**
     * 注销
     *
     * @param obj
     */
    public void unregister(Object obj) {
        List<SubscribeMethod> subscribeMethods = ReflectionHelper.getTypeObjSubscribeMethod(obj, EventBus.getInstance().getSubscribeMethodList());
        for (SubscribeMethod subscribeMethod : subscribeMethods) {
            EventBus.getInstance().getSubscribeMethodList().remove(subscribeMethod);
        }
    
    }

![这里写图片描述][20160724181722740]

反射处理类 ReflectionHelper :

public class **ReflectionHelper** \{  
private static final String TAG = ReflectionHelper.class.getSimpleName();

/**
     * 获取 含有 @Subscriber 的方法
     *
     * @param obj
     * @param subscribeMethodList
     */
    public static void getSubscribeMethods(Object obj, List<SubscribeMethod> subscribeMethodList) {
        Class clazz = obj.getClass();
        Method[] methods = clazz.getDeclaredMethods();
        for (Method method : methods) {
            if (method.isAnnotationPresent(Subscriber.class) && method.getParameterTypes().length == 1) {
                Subscriber subscriber = method.getAnnotation(Subscriber.class);
                Class parameters = method.getParameterTypes()[0];
                SubscribeMethod subscribeMethod = new SubscribeMethod();
                subscribeMethod.setObject(obj);
                subscribeMethod.setMethod(method);
                subscribeMethod.setParameters(parameters);
                subscribeMethod.setSubscriberType(subscriber.type());
                subscribeMethodList.add(subscribeMethod);
            }
        }
    }
    
    /**
     *
     * 根据 Post 函数里面的参数 获取 有这些参数的方法
     * @param parameter
     * @param subscribeMethodList
     * @return
     */
    public static List<SubscribeMethod> getTypeSubscribeMethods(Object parameter, List<SubscribeMethod> subscribeMethodList) {
        Class<?> clazz = parameter.getClass();
        List<SubscribeMethod> typeSubscribeMethodList = new ArrayList<>();
        for (SubscribeMethod subMethod : subscribeMethodList) {
            if (clazz.equals(subMethod.getParameters())) {
                typeSubscribeMethodList.add(subMethod);
            }
        }
        return typeSubscribeMethodList;
    }
    
    
    /**
     * 执行
     *
     * @param subscribeMethod
     * @param parameter
     */
    public static void invokeSubscribeMethod(SubscribeMethod subscribeMethod, Object parameter) {
        Method method = subscribeMethod.getMethod();
        Object object = subscribeMethod.getObject();
        try {
            method.setAccessible(true);
            method.invoke(object, parameter);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
    }
    
    /**
     * 根据 obj 获取 列表
     *
     * @param obj
     * @param subscribeMethodList
     * @return
     */
    public static List<SubscribeMethod> getTypeObjSubscribeMethod(Object obj, List<SubscribeMethod> subscribeMethodList) {
        List<SubscribeMethod> typeSubscribeMethodList = new ArrayList<>();
        for (SubscribeMethod subMethod : subscribeMethodList) {
            if (obj.equals(subMethod.getObject())) {
                typeSubscribeMethodList.add(subMethod);
            }
        }
        return typeSubscribeMethodList;
    }

EventBus 事件处理类：

public class EventBus \{  
private static EventBus instance;

private List<SubscribeMethod> subscribeMethodList = new ArrayList<>();
    
    private DistributeManeger distributeManeger = new DistributeManeger();
    
    /**
     * @return
     */
    public static EventBus getInstance() {
        if (null == instance)
            newInstance();
        return instance;
    }
    
    /**
     * 初始化实例
     */
    private static synchronized void newInstance() {
        if (null == instance) {
            instance = new EventBus();
        }
    }
    
    /**
     * 注册某对象
     * 1 . 获取含有注解的方法 参数
     *
     * @param obj
     */
    public void register(Object obj) {
        ReflectionHelper.getSubscribeMethods(obj, subscribeMethodList);
    }
    
    /**
     * 发送事件
     *
     * @param obj
     */
    public void post(Object obj) {
        distributeManeger.post(obj);
    }
    
    /**
     * 反注册某对象
     *
     * @param obj
     */
    public void unregister(Object obj) {
        distributeManeger.unregister(obj);
    }
    
    /**
     *
     * @return
     */
    public List<SubscribeMethod> getSubscribeMethodList() {
        return subscribeMethodList;
    }

好到此 代码写完了 接下来就是 测试及使用 最后总结一下。

[20160724175319589]: /images/20220719/cae910feab984b54a1be61cbf192162b.png
[20160724175950624]: /images/20220719/64c3c56d0a7c47f9ba078247c19c2b4b.png
[20160724181722740]: /images/20220719/57ab3664ca74449d868b6d787477a617.png