[Java知识库]spring boot基于NoSQL数据库Redis发送接收存储消息

spring boot里面利用Redis发送、接收、存储消息很方便。写一个消息接收器：

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;

import java.util.UUID;
import java.util.concurrent.atomic.AtomicInteger;

public class MsgReceiver {
    @Autowired
    StringRedisTemplate mStringRedisTemplate;

    private AtomicInteger counter = new AtomicInteger();

    public void receive(String message) {
        System.out.println("收到消息 <" + message + "> " + counter.get());
        
        //将收到的消息存储到Redis数据库中。
        mStringRedisTemplate.opsForValue().set(UUID.randomUUID().toString(), message);

        counter.incrementAndGet();
    }

    public int getCount() {
        return counter.get();
    }
}

application里面进行消息的发送：

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.listener.PatternTopic;
import org.springframework.data.redis.listener.RedisMessageListenerContainer;
import org.springframework.data.redis.listener.adapter.MessageListenerAdapter;

@SpringBootApplication
public class SpringRedisMessageApplication {
    private static final String CHAT_CHANNEL = "聊天";

    @Bean
    public RedisMessageListenerContainer container(RedisConnectionFactory factory, MessageListenerAdapter adapter) {
        RedisMessageListenerContainer container = new RedisMessageListenerContainer();
        container.setConnectionFactory(factory);
        container.addMessageListener(adapter, new PatternTopic(CHAT_CHANNEL));
        return container;
    }

    @Bean
    public MessageListenerAdapter messageListenerAdapter(MsgReceiver msgReceiver) {
        return new MessageListenerAdapter(msgReceiver, "receive"); //"receive"对应MsgReceiver里面定义的函数名称
    }

    @Bean
    public MsgReceiver receiver() {
        return new MsgReceiver();
    }

    @Bean
    public StringRedisTemplate template(RedisConnectionFactory factory) {
        return new StringRedisTemplate(factory);
    }

    public static void main(String[] args) {
        ApplicationContext ctx = SpringApplication.run(SpringRedisMessageApplication.class, args);

        StringRedisTemplate template = ctx.getBean(StringRedisTemplate.class);
        MsgReceiver receiver = ctx.getBean(MsgReceiver.class);

        int total = 5;
        while (true) {
            if (receiver.getCount() == total) {
                System.out.println("已经发送条" + total + "条消息");
                break;
            }

            System.out.println("发送消息...");
            String msg = "[Message]: Hello,world! @" + System.currentTimeMillis();
            template.convertAndSend(CHAT_CHANNEL, msg);
            System.out.println(msg + "发送完毕");

            try {
                Thread.sleep(100);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        System.exit(0);
    }
}

运行application前，先把Redis服务器启动起来。application跑起来后输出：

发送消息...
[Message]: Hello,world! @1642649316292发送完毕
收到消息 <[Message]: Hello,world! @1642649316292> 0
发送消息...
[Message]: Hello,world! @1642649316402发送完毕
收到消息 <[Message]: Hello,world! @1642649316402> 1
发送消息...
[Message]: Hello,world! @1642649316504发送完毕
收到消息 <[Message]: Hello,world! @1642649316504> 2
发送消息...
[Message]: Hello,world! @1642649316606发送完毕
收到消息 <[Message]: Hello,world! @1642649316606> 3
发送消息...
[Message]: Hello,world! @1642649316708发送完毕
收到消息 <[Message]: Hello,world! @1642649316708> 4
已经发送条5条消息

Process finished with exit code 0

用Redis的GUI数据库管理工具，可以看到消息已经存到数据库里面：