RabbitMQ获取队列的消息数目

使用RabbitMQ，业务需求，想要知道队列中还有多少待消费待数据。

方式一：

@Value("${spring.rabbitmq.host}")
private String host;
 
@Value("${spring.rabbitmq.port}")
private Integer port;
 
@Value("${spring.rabbitmq.username}")
private String username;
 
@Value("${spring.rabbitmq.password}")
private String password;
 
ConnectionFactory factory = new ConnectionFactory();
//设置ip，port，用户名和秘密
factory.setHost(host);
factory.setPort(port);
factory.setUsername(username);
factory.setPassword(password);
 
//创建链接
Connection connection = factory.newConnection();
 
//创建信道
Channel channel = connection.createChannel();
 
//创建一个type=direct 持久化的 非自动删除的交换器
channel.exchangeDeclare(EXCHANGE_NAME, "direct", true, false, null);

String []queues = queueNames.split(",");
for(String queue : queues){
   DeclareOk declareOk = channel.queueDeclarePassive(queue);
   //获取队列中的消息个数
   int num = declareOk.getMessageCount();
   
}

方式二：

spring配置文件：

<!-- 连接配置 -->
<rabbit:connection-factory id="rabbitConnectionFactory" host="#{app['mq.broker.host']}" port="#{app['mq.broker.port']}" username="#{app['mq.broker.username']}" password="#{app['mq.broker.password']}" virtual-host="/" publisher-confirms="true"/>

<!-- mq模板 -->
<rabbit:template id="rabbitTemplate" connectionfactory="rabbitConnectionFactory" message-converter="jsonMessageConverter"/>

java代码：

@Autowired
private RabbitTemplate rabbitTemplate;

ConnectionFactory connectionFactory = rabbitTemplate.getConnectionFactory();
// 创建连接
Connection connection = connectionFactory.createConnection();
// 创建通道
Channel channel = connection.createChannel(false);
// 设置消息交换机
channel.exchangeDeclare("amp.topic", "direct", true, false, null);
DeclareOk declareOk = channel.queueDeclarePassive(LETTER_CLASS_QUEUE);
//获取队列中的消息个数
int queueCount = declareOk.getMessageCount();
result.put("queueCount", String.valueOf(queueCount));
// 关闭通道和连接
channel.close();
connection.close();