Spring Data Redis實現一個訂閱/發布系統

jopen 12年前發布 | 117K 次閱讀 Redis NoSQL數據庫 Spring Data

Redis是一個key-value的存儲系統,提供的key-value類似與Memcached而數據結構又多于memcached,而且性能優異.廣泛用于緩存,臨時存儲等.而我今天這個例子是使用Redis實現一個訂閱/發布系統,而不是如何使用它存儲key-value的數據.

Redis是天生支持訂閱/發布的,不是我牽強附會拼湊而實現這樣的效果,如果真是這樣性能沒法保證,而且要實現訂閱/發布這樣的系統是有很多解決方案的.

下載,安裝和配置Redis

Spring一直秉承不發明輪子的,對于很多其他技術都是提供一個模板:Template,如JDBC-JdbcTemplate,JMSTemplate等,Redis他也提供RedisTemplate,有了這個RedisTemplate你可以做任何事,存取key-value,訂閱,發布等都通過這個對象實現.

實現一個RedisDAO,接口我不貼了

public class RedisDAOImpl implements RedisDAO {

private RedisTemplate<String, Object> redisTemplate = null;

public RedisDAOImpl() {

}

@Override
public void sendMessage(String channel, Serializable message) {
    redisTemplate.convertAndSend(channel, message);
}


public RedisTemplate getRedisTemplate() {
    return redisTemplate;
}

public void setRedisTemplate(RedisTemplate redisTemplate) {
    this.redisTemplate = redisTemplate;
}

}</pre>可以看到,通過這個 sendMessage方法,我可以把一條可序列化的消息發送到channel頻道,訂閱者只要訂閱了這個channel,他就會接收發布者發布的消息. 



當然有了發布消息的sendMessage也得有個接收消息的Listener,用于接收訂閱到的消息. 

代碼如: 

public class MessageDelegateListenerImpl implements MessageDelegateListener {

    @Override
    public void handleMessage(Serializable message) {
        //什么都不做,只輸出
        if(message == null){
            System.out.println("null");
        } else if(message.getClass().isArray()){
            System.out.println(Arrays.toString((Object[])message));
        } else if(message instanceof List<?>) {
            System.out.println(message);
        } else if(message instanceof Map<? , ?>) {
            System.out.println(message);
        } else {
            System.out.println(ToStringBuilder.reflectionToString(message));
        }
    }
}
好了,有上面的兩個類,加上Spring基本上就可以工作了.當然還得啟動Redis. 

Spring Schema: <?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:redis="http://www.springframework.org/schema/redis"
       xmlns:p="http://www.springframework.org/schema/p"

       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context-3.0.xsd
       http://www.springframework.org/schema/redis
        http://www.springframework.org/schema/redis/spring-redis-1.0.xsd">

    <bean id="redisConnectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"
          p:hostName="localhost" p:port="6379" p:usePool="true">
    </bean>

    <!-- redis template definition -->
    <bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate"
          p:connectionFactory-ref="redisConnectionFactory"/>

    <bean id="redisDAO" class="net.dredis.dao.impl.RedisDAOImpl">
        <property name="redisTemplate" ref="redisTemplate" />
    </bean>

    <bean id="listener" class="net.dredis.listener.impl.MessageDelegateListenerImpl"/>

    <!-- the default ConnectionFactory -->
    <bean id="jdkSerializer" class="org.springframework.data.redis.serializer.JdkSerializationRedisSerializer" />

    <redis:listener-container>
        <!-- the method attribute can be skipped as the default method name is "handleMessage" -->
        <redis:listener ref="listener" serializer="jdkSerializer" method="handleMessage" topic="java" />
    </redis:listener-container>
</beans>
如上面的配置, jdkSerializer是jdk默認的序列化的實現,當然還有很多其他序列化Java對象的方法,這里使用jdk默認實現. 

Method屬性是配置訂閱系統接收消息的方法,默認也是"handleMessage" 

topic就是訂閱的channel頻道,是有發布到java這個channel的消息才會被接收. 



測試類: 

public static void main(String[] args) {
        new ClassPathXmlApplicationContext("pubsubAppContext1.xml");;
        while (true) { //這里是一個死循環,目的就是讓進程不退出,用于接收發布的消息
            try {
                System.out.println("current time: " + new Date());

                Thread.sleep(3000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
OK,啟動了訂閱系統后,我們就可以發布消息,測試類如: 

@Test
    public void testPublishMessage() throws Exception {
        String msg = "Hello, Redis!";
        redisDAO.sendMessage("java", msg); //發布字符串消息


        RedisTestBean bean = new RedisTestBean("123456");
        bean.setName("ZhenQin");
        bean.setOld((byte)23);
        bean.setSeliry((short)4000);
        bean.setManbers(new String[]{"234567", "3456789"});
        redisDAO.sendMessage("java", bean); //發布一個普通的javabean消息


        Integer[] values = new Integer[]{21341,123123,12323};
        redisDAO.sendMessage("java", values);  //發布一個數組消息
    }
如測試,我連續發布了3條消息,都是不同的數據類型.訂閱端輸出如: current time: Fri Oct 26 20:38:31 CST 2012
[21341, 123123, 12323]
java.lang.String@379faa8c[value={H,e,l,l,o,,, ,R,e,d,i,s,!},hash=1345989452]
net.dredis.entity.RedisTestBean@7dee05dc[uid=123456,name=ZhenQin,seliry=4000,old=23,manbers={234567,3456789}]
current time: Fri Oct 26 20:38:34 CST 2012
current time: Fri Oct 26 20:38:37 CST 2012
OK他接收到了這3條消息,而且和預期一樣. 

對于Spring還有傳統風格的配置方式,實現的功能和前面一模一樣. 

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:p="http://www.springframework.org/schema/p"

       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <bean id="jedisConnectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"
          p:hostName="localhost" p:port="6379" p:usePool="true">
    </bean>

    <!-- redis template definition -->
    <bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate"
          p:connectionFactory-ref="jedisConnectionFactory"/>

    <bean id="redisDAO" class="net.dredis.dao.impl.RedisDAOImpl">
        <property name="redisTemplate" ref="redisTemplate" />
    </bean>

    <bean id="serialization" class="org.springframework.data.redis.serializer.JdkSerializationRedisSerializer" />

    <bean id="messageDelegateListener" class="net.dredis.listener.impl.MessageDelegateListenerImpl" />

    <bean id="messageListener" class="org.springframework.data.redis.listener.adapter.MessageListenerAdapter">
        <property name="delegate" ref="messageDelegateListener" />
        <property name="serializer" ref="serialization" />
    </bean>

    <bean id="redisContainer" class="org.springframework.data.redis.listener.RedisMessageListenerContainer">
        <property name="connectionFactory" ref="jedisConnectionFactory"/>
        <property name="messageListeners">
            <!-- map of listeners and their associated topics (channels or/and patterns) -->
            <map>
                <entry key-ref="messageListener">
                    <bean class="org.springframework.data.redis.listener.ChannelTopic">
                        <constructor-arg value="java" />
                    </bean>
                </entry>
            </map>
        </property>
    </bean>
</beans>

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Redis NoSQL數據庫 Spring Data

Spring Data Redis實現一個訂閱/發布系統

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