(1). 概述
在这一小篇,主要了解一下,SI抽象了哪些接口.
(2). Message
Message是SI对消息载体的抽象,一般是由MessageBuilder创建.
package org.springframework.messaging;
// 通过MessageBuilder构建出一个消息.
// org.springframework.messaging.support.MessageBuilder
public interface Message<T> {
// 消息体
T getPayload();
// 消息头
MessageHeaders getHeaders();
}
(3). MessageChannel
MessageChannel是SI对”发送消息”能力的一个抽象.
package org.springframework.messaging;
public interface MessageChannel {
long INDEFINITE_TIMEOUT = -1;
// 发送消息
boolean send(Message<?> message);
// 发送消息,并定义发送消息的超时时间
boolean send(Message<?> message, long timeout);
}
(4). SubscribableChannel
SubscribableChannel是SI”接受消息能力”的抽象.
package org.springframework.messaging;
public interface SubscribableChannel extends MessageChannel {
/**
* 绑定消息的处理
* Register a message handler.
* @return {@code true} if the handler was subscribed or {@code false} if it
* was already subscribed.
*/
boolean subscribe(MessageHandler handler);
/**
* 解绑消息的处理
* Un-register a message handler.
* @return {@code true} if the handler was un-registered, or {@code false}
* if was not registered.
*/
boolean unsubscribe(MessageHandler handler);
}
(5). MessageHandler
MessageHandler一看就知道是”消息的处理”抽象.
package org.springframework.messaging;
// 消息的处理
public interface MessageHandler {
/**
* 消息的处理模型
* Handle the given message.
* @param message the message to be handled
* @throws MessagingException if the handler failed to process the message
*/
void handleMessage(Message<?> message) throws MessagingException;
}
