ActiveMQ之二--JMS消息类型
1.前言
根据Message接口的方法,可以获取消息类型
根据 JSR 914: JavaTM Message Service (JMS) API ,JMS规范中的消息类型包括TextMessage、BytesMessage、MapMessage、StreamMessage和ObjectMessage 等五种。ActiveMQ也有对应的实现,下面我们结合Spring JMS分别来看一下五种消息类型的收发代码。
2. 消息发送示例代码
/** * 向默认队列发送text消息 */ public void sendMessage(final String msg) { String destination = jmsTemplate.getDefaultDestination().toString(); System.out.println("ProducerService向队列" + destination + "发送了消息:\t" + msg); jmsTemplate.send(new MessageCreator() { public Message createMessage(Session session) throws JMSException { return session.createTextMessage(msg); } }); } /** * 向默认队列发送map消息 */ public void sendMapMessage() { jmsTemplate.send(new MessageCreator() { public Message createMessage(Session session) throws JMSException { MapMessage message = session.createMapMessage(); message.setString("name", "小西山"); return message; } }); } /** * 向默认队列发送Object消息 */ public void sendObjectMessage() { jmsTemplate.send(new MessageCreator() { public Message createMessage(Session session) throws JMSException { Staff staff = new Staff(1, "搬砖工"); // Staff必须实现序列化 ObjectMessage message = session.createObjectMessage(staff); return message; } }); } /** * 向默认队列发送Bytes消息 */ public void sendBytesMessage() { jmsTemplate.send(new MessageCreator() { public Message createMessage(Session session) throws JMSException { String str = "BytesMessage 字节消息"; BytesMessage message = session.createBytesMessage(); message.writeBytes(str.getBytes()); return message; } }); } /** * 向默认队列发送Stream消息 */ public void sendStreamMessage() { jmsTemplate.send(new MessageCreator() { public Message createMessage(Session session) throws JMSException { String str = "StreamMessage 流消息"; StreamMessage message = session.createStreamMessage(); message.writeString(str); message.writeInt(521); return message; } }); }
3.消息接受示例代码
/** * 接受消息 */ public void receive(Destination destination) throws JMSException { Message message = jmsTemplate.receive(destination); // 如果是文本消息 if (message instanceof TextMessage) { TextMessage tm = (TextMessage) message; System.out.println("ConsumerService从队列" + destination.toString() + "收到了消息:\t" + tm.getText()); } // 如果是Map消息 if (message instanceof MapMessage) { MapMessage mm = (MapMessage) message; System.out.println("ConsumerService从队列" + destination.toString() + "收到了消息:\t" + mm.getString("name")); } // 如果是Object消息 if (message instanceof ObjectMessage) { ObjectMessage om = (ObjectMessage) message; Staff staff = (Staff) om.getObject(); System.out.println("ConsumerService从队列" + destination.toString() + "收到了消息:\t" + staff); } // 如果是bytes消息 if (message instanceof BytesMessage) { byte[] b = new byte[1024]; int len = -1; BytesMessage bm = (BytesMessage) message; while ((len = bm.readBytes(b)) != -1) { System.out.println(new String(b, 0, len)); } } // 如果是Stream消息 if (message instanceof StreamMessage) { StreamMessage sm = (StreamMessage) message; System.out.println(sm.readString()); System.out.println(sm.readInt()); } }