RabbitMQ学习之spring-amqp的重要类的认识

 对于大多数应用来说都做了与spring整合，对于rabbitmq来说。也有与spring的整合。可能通过spring的官网找到spring-amqp项目下载。spring-amqp项目包括三个子项目：spring-amqp、spring-erlang、spring-rabbit.

   下面来认识一下spring-amqp中的几个重要类；以spring-amqp-1.0.0.M3版本为例
    1、Message : Spring AMQP定义的Message类是AMQP域模型中代表之一。Message类封装了body(消息BODY)和properties（消息属性） 。使得这个API看起来很简单。Message类定义如下：

public class Message {
private final MessageProperties messageProperties;

private final byte[] body;

public Message(byte[] body, MessageProperties messageProperties) {
this.body = body;
this.messageProperties = messageProperties;
}

public byte[] getBody() {
return this.body;
}

public MessageProperties getMessageProperties() {
return this.messageProperties;
}

}

其中MessageProperties类中定义了例如messageId、timestamp、contentType等属性。这此属性可以扩展到用户通过setHeader(String key, Object value)方法来自定义“headers”。

 2、Exchange

      Exchange接口代表一个AMQP的Exchange，决定消息生产者发送消息。每个Exchange都包括一个特定的唯一名字的虚拟主机的代理和一些其他属性。

public interface Exchange {

String getName();

String getType();

boolean isDurable();

boolean isAutoDelete();

Map<String, Object> getArguments();

}

其中 AbstractExchange类实现了Exchange类。而DirectExchange、TopicExchange、FanoutExchang、HeadersExchange四个类继承AbstractExchange。并重写了getType()类。根据各自相对应的Exchange类型。DirectExchange、TopicExchange、FanoutExchang、HeadersExchange分别对应的类型为direct,topic,fanout,headers.

 3、Queue

 Queue类是消息消费者接收消息中重要的一个组成部分。通过与Exchange判定来肯定消费者所接收的消息。伪代码如下：

public class Queue {
private final String name;
private volatile boolean durable;
private volatile boolean exclusive;
private volatile boolean autoDelete;
private volatile Map<String, Object> arguments;
public Queue(String name) {
this.name = name;
}

其中name表示队列的名称、durable表示持久性。true表示是。exclusive表示独占性。由于在AmqpTemplate中提供一个方法来得到唯一的队列。这个队列可能是一个”reply-to“地址或者其他信息，因此一般exclusive和autoDelete一般设定为true.

4、Binding

     Bingding类通过多种构造参数来判定Exchange,Queue,routingkey;例如

Binding(Queue queue, FanoutExchange exchange)
Binding(Queue queue, HeadersExchange exchange, Map<String, Object> arguments)
Binding(Queue queue, DirectExchange exchange)
Binding(Queue queue, DirectExchange exchange, String routingKey)
Binding(Queue queue, TopicExchange exchange, String routingKey)

5、AmqpTemplate

AmqpTemplate是用来发送消息的模板类 

/**
* Specifies a basic set of AMQP operations.
*
* Provides synchronous send and receive methods. The {@link #convertAndSend(Object)} and {@link #receiveAndConvert()}
* methods allow let you send and receive POJO objects. Implementations are expected to delegate to an instance of
* {@link MessageConverter} to perform conversion to and from AMQP byte[] payload type.
*
* @author Mark Pollack
* @author Mark Fisher
*/
public interface AmqpTemplate {

// send methods for messages

/**
* Send a message to a default exchange with a default routing key.
*
* @param message a message to send
* @throws AmqpException if there is a problem
*/
void send(Message message) throws AmqpException;

/**
* Send a message to a default exchange with a specific routing key.
*
* @param routingKey the routing key
* @param message a message to send
* @throws AmqpException if there is a problem
*/
void send(String routingKey, Message message) throws AmqpException;

/**
* Send a message to a specific exchange with a specific routing key.
*
* @param exchange the name of the exchange
* @param routingKey the routing key
* @param message a message to send
* @throws AmqpException if there is a problem
*/
void send(String exchange, String routingKey, Message message) throws AmqpException;

// send methods with conversion

/**
* Convert a Java object to an Amqp {@link Message} and send it to a default exchange with a default routing key.
*
* @param message a message to send
* @throws AmqpException if there is a problem
*/
void convertAndSend(Object message) throws AmqpException;

/**
* Convert a Java object to an Amqp {@link Message} and send it to a default exchange with a specific routing key.
*
* @param routingKey the routing key
* @param message a message to send
* @throws AmqpException if there is a problem
*/
void convertAndSend(String routingKey, Object message) throws AmqpException;

/**
* Convert a Java object to an Amqp {@link Message} and send it to a specific exchange with a specific routing key.
*
* @param exchange the name of the exchange
* @param routingKey the routing key
* @param message a message to send
* @throws AmqpException if there is a problem
*/
void convertAndSend(String exchange, String routingKey, Object message) throws AmqpException;

/**
* Convert a Java object to an Amqp {@link Message} and send it to a default exchange with a default routing key.
*
* @param message a message to send
* @param messagePostProcessor a processor to apply to the message before it is sent
* @throws AmqpException if there is a problem
*/
void convertAndSend(Object message, MessagePostProcessor messagePostProcessor) throws AmqpException;

/**
* Convert a Java object to an Amqp {@link Message} and send it to a default exchange with a specific routing key.
*
* @param routingKey the routing key
* @param message a message to send
* @param messagePostProcessor a processor to apply to the message before it is sent
* @throws AmqpException if there is a problem
*/
void convertAndSend(String routingKey, Object message, MessagePostProcessor messagePostProcessor)
throws AmqpException;

/**
* Convert a Java object to an Amqp {@link Message} and send it to a specific exchange with a specific routing key.
*
* @param exchange the name of the exchange
* @param routingKey the routing key
* @param message a message to send
* @param messagePostProcessor a processor to apply to the message before it is sent
* @throws AmqpException if there is a problem
*/
void convertAndSend(String exchange, String routingKey, Object message, MessagePostProcessor messagePostProcessor)
throws AmqpException;

// receive methods for messages

/**
* Receive a message if there is one from a default queue. Returns immediately, possibly with a null value.
*
* @return a message or null if there is none waiting
* @throws AmqpException if there is a problem
*/
Message receive() throws AmqpException;

/**
* Receive a message if there is one from a specific queue. Returns immediately, possibly with a null value.
*
* @param queueName the name of the queue to poll
* @return a message or null if there is none waiting
* @throws AmqpException if there is a problem
*/
Message receive(String queueName) throws AmqpException;

// receive methods with conversion

/**
* Receive a message if there is one from a default queue and convert it to a Java object. Returns immediately,
* possibly with a null value.
*
* @return a message or null if there is none waiting
* @throws AmqpException if there is a problem
*/
Object receiveAndConvert() throws AmqpException;

/**
* Receive a message if there is one from a specific queue and convert it to a Java object. Returns immediately,
* possibly with a null value.
*
* @param queueName the name of the queue to poll
* @return a message or null if there is none waiting
* @throws AmqpException if there is a problem
*/
Object receiveAndConvert(String queueName) throws AmqpException;

// send and receive methods for messages

/**
* Basic RPC pattern. Send a message to a default exchange with a default routing key and attempt to receive a
* response. Implementations will normally set the reply-to header to an exclusive queue and wait up for some time
* limited by a timeout.
*
* @param message a message to send
* @return the response if there is one
* @throws AmqpException if there is a problem
*/
Message sendAndReceive(Message message) throws AmqpException;

/**
* Basic RPC pattern. Send a message to a default exchange with a specific routing key and attempt to receive a
* response. Implementations will normally set the reply-to header to an exclusive queue and wait up for some time
* limited by a timeout.
*
* @param routingKey the routing key
* @param message a message to send
* @return the response if there is one
* @throws AmqpException if there is a problem
*/
Message sendAndReceive(String routingKey, Message message) throws AmqpException;

/**
* Basic RPC pattern. Send a message to a specific exchange with a specific routing key and attempt to receive a
* response. Implementations will normally set the reply-to header to an exclusive queue and wait up for some time
* limited by a timeout.
*
* @param exchange the name of the exchange
* @param routingKey the routing key
* @param message a message to send
* @return the response if there is one
* @throws AmqpException if there is a problem
*/
Message sendAndReceive(String exchange, String routingKey, Message message) throws AmqpException;

// send and receive methods with conversion

/**
* Basic RPC pattern with conversion. Send a Java object converted to a message to a default exchange with a default
* routing key and attempt to receive a response, converting that to a Java object. Implementations will normally
* set the reply-to header to an exclusive queue and wait up for some time limited by a timeout.
*
* @param message a message to send
* @return the response if there is one
* @throws AmqpException if there is a problem
*/
Object convertSendAndReceive(Object message) throws AmqpException;

/**
* Basic RPC pattern with conversion. Send a Java object converted to a message to a default exchange with a
* specific routing key and attempt to receive a response, converting that to a Java object. Implementations will
* normally set the reply-to header to an exclusive queue and wait up for some time limited by a timeout.
*
* @param routingKey the routing key
* @param message a message to send
* @return the response if there is one
* @throws AmqpException if there is a problem
*/
Object convertSendAndReceive(String routingKey, Object message) throws AmqpException;

/**
* Basic RPC pattern with conversion. Send a Java object converted to a message to a specific exchange with a
* specific routing key and attempt to receive a response, converting that to a Java object. Implementations will
* normally set the reply-to header to an exclusive queue and wait up for some time limited by a timeout.
*
* @param exchange the name of the exchange
* @param routingKey the routing key
* @param message a message to send
* @return the response if there is one
* @throws AmqpException if there is a problem
*/
Object convertSendAndReceive(String exchange, String routingKey, Object message) throws AmqpException;

/**
* Basic RPC pattern with conversion. Send a Java object converted to a message to a default exchange with a default
* routing key and attempt to receive a response, converting that to a Java object. Implementations will normally
* set the reply-to header to an exclusive queue and wait up for some time limited by a timeout.
*
* @param message a message to send
* @param messagePostProcessor a processor to apply to the message before it is sent
* @return the response if there is one
* @throws AmqpException if there is a problem
*/
Object convertSendAndReceive(Object message, MessagePostProcessor messagePostProcessor) throws AmqpException;

/**
* Basic RPC pattern with conversion. Send a Java object converted to a message to a default exchange with a
* specific routing key and attempt to receive a response, converting that to a Java object. Implementations will
* normally set the reply-to header to an exclusive queue and wait up for some time limited by a timeout.
*
* @param routingKey the routing key
* @param message a message to send
* @param messagePostProcessor a processor to apply to the message before it is sent
* @return the response if there is one
* @throws AmqpException if there is a problem
*/
Object convertSendAndReceive(String routingKey, Object message, MessagePostProcessor messagePostProcessor) throws AmqpException;

/**
* Basic RPC pattern with conversion. Send a Java object converted to a message to a specific exchange with a
* specific routing key and attempt to receive a response, converting that to a Java object. Implementations will
* normally set the reply-to header to an exclusive queue and wait up for some time limited by a timeout.
*
* @param exchange the name of the exchange
* @param routingKey the routing key
* @param message a message to send
* @param messagePostProcessor a processor to apply to the message before it is sent
* @return the response if there is one
* @throws AmqpException if there is a problem
*/
Object convertSendAndReceive(String exchange, String routingKey, Object message, MessagePostProcessor messagePostProcessor) throws AmqpException;
}

 6、AmqpAdmin和RabbitAdmin

   用户配置Queue、Exchange、Binding的代理类。代理类会自动声明或创建这些配置信息。

下面这个类用于异步接收消息的处理类
  7、MessageConverter 消息转换器类
 8、SimpleMessageListenerContainer 监听消息容器类

spring-amqp:

http://projects.spring.io/spring-amqp/

https://github.com/spring-projects/spring-amqp-samples

转载：http://wubin850219.iteye.com/blog/1050251