Andoid 总线设计 (三)

具体的代码设计：



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;

}



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);
}

}

}



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。