rabbitmq实现定时任务 java代码

以下是一个使用 RabbitMQ 实现定时任务的 Java 代码示例：

import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

public class RabbitMQDelayTask {

    private final static String EXCHANGE_NAME = "delayed";
    private final static String QUEUE_NAME = "task_queue";
    private final static String ROUTING_KEY = "";

    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");

        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        // 创建延迟交换机
        channel.exchangeDeclare(EXCHANGE_NAME, "x-delayed-message", true, false, null);
        // 创建队列并绑定到延迟交换机上
        channel.queueDeclare(QUEUE_NAME, true, false, false, null);
        channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, ROUTING_KEY);

        String message = "Task message";
        int delayTime = 5000; // 延迟时间为 5 秒

        // 发送任务消息并设置延迟时间
        AMQP.BasicProperties.Builder builder = new AMQP.BasicProperties.Builder();
        builder.headers(java.util.Collections.<String, Object>singletonMap("x-delay", delayTime));

        channel.basicPublish(EXCHANGE_NAME, ROUTING_KEY, builder.build(), message.getBytes("UTF-8"));

        channel.close();
        connection.close();
    }
}

注意，以上代码仅为示例，实际使用时需要根据具体需求进行相应的修改。同时，需要添加 RabbitMQ 客户端依赖库，例如 amqp-client 库。