redis 入门（二）——maven4.0 + Jedis2.9.0 + redis3.2.6 实战

MickyInvQ

发布于 2020-09-27 17:23:09

6300

发布于 2020-09-27 17:23:09

文章被收录于专栏：InvQ的专栏InvQ的专栏

用Memcached，对于缓存对象大小有要求，单个对象不得大于1MB，且不支持复杂的数据类型，譬如SET等。基于这些限制，有必要考虑Redis！

言归正传，目前Redis大概有3中基于Java语言的Client：

Jredis
Jedis
Redis4J 这里只说Jedis，因为它是官方提供的唯一Redis Client For Java Provider！

一、简单使用Jedis

需要Jedis就从Maven获取吧！ Maven Pom.xml

   <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
            <version>2.9.0</version>
            <type>jar</type>
            <scope>compile</scope>
        </dependency>

jedis 的简单实用：

package redis;
import redis.clients.jedis.Jedis;

import java.util.List;

public class HelloRedis {
    public static void main(String[] args){

        Jedis jedis = new Jedis("10.20.112.33",6379);
        System.out.println("Connection to server sucessfully");
        //check whether server is running or not
        System.out.println("Server is running: "+jedis.ping());
        jedis.lpush("wonder-list", "Redis");
        jedis.lpush("wonder-list", "Mongodb");
        jedis.lpush("wonder-list", "Mysql");
        // Get the stored data and print it
        List<String> list = jedis.lrange("wonder-list", 0 ,5);
        for(int i=0; i<list.size(); i++) {
            System.out.println("Stored string in redis:: "+list.get(i));
        }

    }
}

二、池化使用Jedis

Jedis使用commons-pool完成池化实现。

先做个配置文件：

#最大分配的对象数
redis.pool.maxTotal=1024
#最大能够保持idle状态的对象数
redis.pool.maxIdle=200
#当池内没有返回对象时，最大等待时间，单位为妙
redis.pool.maxWait=1000
#当调用borrow Object方法时，是否进行有效性检查
redis.pool.testOnBorrow=true
#当调用return Object方法时，是否进行有效性检查
redis.pool.testOnReturn=true
#连接超时时是否阻塞，false时报异常,ture阻塞直到超时, 默认true
redis.pool.blockWhenExhausted=true
#超时时间 默认2000
redis.timeout=2000
#IP
redis.host=10.20.112.33
#Port
redis.port=6379

在静态代码中完成初始化

package redis;

import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;

import java.util.ResourceBundle;

public class  JedisConfig{

public static JedisPool pool;

static {

        ResourceBundle bundle = ResourceBundle.getBundle("redisProperty.redis");
        if (bundle == null) {
                throw new IllegalArgumentException("[redis.properties] is not found!");
        }
        JedisPoolConfig config = new JedisPoolConfig();
        config.setMaxTotal(Integer.valueOf(bundle.getString("redis.pool.maxTotal")));
        config.setMaxIdle(Integer.valueOf(bundle.getString("redis.pool.maxIdle")));
        config.setMaxWaitMillis(Long.valueOf(bundle.getString("redis.pool.maxWait")));
        config.setTestOnBorrow(Boolean.valueOf(bundle.getString("redis.pool.testOnBorrow")));
        config.setTestOnReturn(Boolean.valueOf(bundle.getString("redis.pool.testOnReturn")));

        pool = new JedisPool(config, bundle.getString("redis.host"),Integer.valueOf(bundle.getString("redis.port")));
        }
}

然后，修改前面那段jedis代码主要是更改获取方式改为从对象池中，获取Jedis实例切记，最后使用后，释放Jedis对象

package redis;
import redis.clients.jedis.Jedis;
import redis.clients.util.Pool;

import java.util.List;

public class HelloRedis {
    public static void main(String[] args){

//        Jedis jedis = new Jedis("10.20.112.33",6379);
        // 从池中获取一个Jedis对象
        Jedis jedis = JedisConfig.pool.getResource();
        System.out.println("Connection to server sucessfully");
        //check whether server is running or not
        System.out.println("Server is running: "+jedis.ping());
        jedis.lpush("wonder-list", "Redis");
        jedis.lpush("wonder-list", "Mongodb");
        jedis.lpush("wonder-list", "Mysql");
        // Get the stored data and print it
        List<String> list = jedis.lrange("wonder-list", 0 ,5);
        for(int i=0; i<list.size(); i++) {
            System.out.println("Stored string in redis:: "+list.get(i));
        }
        // 释放对象池
        JedisConfig.pool.close();
    }
}

同样执行成功：

Connection to server sucessfully
Server is running: PONG
Stored string in redis:: Mysql
Stored string in redis:: Mongodb
Stored string in redis:: Redis
Stored string in redis:: Mysql
Stored string in redis:: Mongodb
Stored string in redis:: Redis

三、一致性哈希

Memcached完全基于分布式集群，而Redis是Master-Slave，如果想把Reids，做成集群模式，无外乎多做几套Master-Slave，每套Master-Slave完成各自的容灾处理，通过Client工具，完成一致性哈希。

PS:Memcached是在Server端完成Sharding，Redis只能依靠各个Client做Sharding。可能会在Redis 3.0系列支持Server端Sharding。

JedisShardInfo jedisShardInfo1 = new JedisShardInfo(  
                bundle.getString("redis1.ip"), Integer.valueOf(bundle                       .getString("redis.port")));  
JedisShardInfo jedisShardInfo2 = new JedisShardInfo(  
                bundle.getString("redis2.ip"), Integer.valueOf(bundle                       .getString("redis.port")));  

List<JedisShardInfo> list = new LinkedList<JedisShardInfo>();  
list.add(jedisShardInfo1);  
list.add(jedisShardInfo2);

初始化ShardedJedisPool代替JedisPool：

ShardedJedisPool pool = new ShardedJedisPool(config, list);

改由ShardedJedis，获取Jedis对象：

// 从池中获取一个Jedis对象  
ShardedJedis jedis = JedisConfig.pool.getResource();  
String keys = "name";  
String value = "snowolf";  
// 删数据  
jedis.del(keys);  
// 存数据  
jedis.set(keys, value);  
// 取数据  
String v = jedis.get(keys);  

System.out.println(v);  

// 释放对象池  
pool.close();

四、Spring封装参考

Ok，完成上述代码足够完成简单任务，如果有必要，可以用spring-data-redis封装初始化：

首先加入maven依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.wq</groupId>
    <artifactId>beauty</artifactId>
    <version>1.0-SNAPSHOT</version>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
        <!-- redis 版本 -->
        <redis.version>2.9.0</redis.version>
        <spring.redis.version>1.8.4.RELEASE</spring.redis.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <!-- mail and spring-context-support for send email -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </dependency>

        <dependency>
            <groupId>com.sun.mail</groupId>
            <artifactId>javax.mail</artifactId>
            <version>1.5.2</version>
        </dependency>
        <!-- /email -->
        <!-- mysql驱动 start-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!-- mysql驱动 end-->
        <dependency>
            <groupId>tk.mybatis</groupId>
            <artifactId>mapper-spring-boot-starter</artifactId>
            <version>1.1.0</version>
        </dependency>
        <dependency>
            <groupId>redis.clients</groupId>
            <artifactId>jedis</artifactId>
            <version>${redis.version}</version>
            <type>jar</type>
            <scope>compile</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
            <version>2.0.1.RELEASE</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

创建一个spring-redis.xml：

<?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"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-4.3.xsd"
       default-lazy-init="false">

    <!-- 加载配置文件 -->
    <context:property-placeholder location="classpath:redisProperty/redis.properties" />
    <!-- redis数据源 -->
    <bean id="poolConfig" class="redis.clients.jedis.JedisPoolConfig">
        <!-- 最大空闲数 -->
        <property name="maxIdle" value="${redis.pool.maxIdle}" />
        <!-- 最大空连接数 -->
        <property name="maxTotal" value="${redis.pool.maxTotal}" />
        <!-- 最大等待时间 -->
        <property name="maxWaitMillis" value="${redis.pool.maxWait}" />
        <!-- 连接超时时是否阻塞，false时报异常,ture阻塞直到超时, 默认true -->
        <property name="blockWhenExhausted" value="${redis.pool.blockWhenExhausted}" />
        <!-- 返回连接时，检测连接是否成功 -->
        <property name="testOnBorrow" value="${redis.pool.testOnBorrow}" />
        <property name="testOnReturn" value="${redis.pool.testOnReturn}" />
    </bean>

    <!-- Spring-redis连接池管理工厂 -->
    <bean id="jedisConnectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory">
        <!-- IP地址 -->
        <property name="hostName" value="${redis.host}" />
        <!-- 端口号 -->
        <property name="port" value="${redis.port}" />
        <!-- 超时时间 默认2000-->
        <property name="timeout" value="${redis.timeout}" />
        <!-- 连接池配置引用 -->
        <property name="poolConfig" ref="poolConfig" />
        <!-- usePool：是否使用连接池 -->
        <property name="usePool" value="true"/>
    </bean>

    <!-- redis template definition -->
    <bean id="redisTemplate" class="org.springframework.data.redis.core.RedisTemplate">
        <property name="connectionFactory" ref="jedisConnectionFactory" />
        <property name="keySerializer">
            <bean class="org.springframework.data.redis.serializer.StringRedisSerializer" />
        </property>
        <property name="valueSerializer">
            <bean class="org.springframework.data.redis.serializer.StringRedisSerializer" />
        </property>
        <property name="hashKeySerializer">
            <bean class="org.springframework.data.redis.serializer.StringRedisSerializer" />
        </property>
        <property name="hashValueSerializer">
            <bean class="org.springframework.data.redis.serializer.JdkSerializationRedisSerializer" />
        </property>
        <!--开启事务  -->
        <property name="enableTransactionSupport" value="true"></property>
    </bean>

    <!--自定义redis工具类,在需要缓存的地方注入此类  -->
    <bean id="redisrCacheManager" class="redis.RedisTemplet">
        <property name="redisTemplate" ref="redisTemplate" />
    </bean>
</beans>

创建对应的reidis工具类

package redis;

import org.springframework.data.redis.core.RedisTemplate;


public class RedisTemplet {

        protected RedisTemplate<String, Object> redisTemplate;

        public void setRedisTemplate(RedisTemplate<String, Object> redisTemplate) {
            this.redisTemplate = redisTemplate;
        }
        public  RedisTemplate getRedisTemplate(){
            return redisTemplate;
        }
    }
     /**
     * 获取list缓存的内容
     *
     * @param key
     *            键
     * @param start
     *            开始
     * @param end
     *            结束 0 到 -1代表所有值
     * @return
     */
    public List<Object> lGet(String key, long start, long end) {
        try {
            return redisTemplate.opsForList().range(key, start, end);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

创建test类

import org.junit.Test;
import org.springframework.stereotype.Component;
import redis.JedisConfig;
import redis.RedisTemplet;
import redis.clients.jedis.Jedis;

import javax.annotation.Resource;
import java.util.List;


@Component
public class RedisTest extends BaseTest{
    @Resource(name="redisrCacheManager")
    private RedisTemplet redisTemplet;

    @Test
    public void testByCode(){
//        Jedis jedis = new Jedis("10.20.112.33",6379);
        // 从池中获取一个Jedis对象
        Jedis jedis = JedisConfig.pool.getResource();
        System.out.println("Connection to server sucessfully");
        //check whether server is running or not
        System.out.println("Server is running: "+jedis.ping());
        jedis.lpush("wonder-list", "Redis");
        jedis.lpush("wonder-list", "Mongodb");
        jedis.lpush("wonder-list", "Mysql");
        // Get the stored data and print it
        List<String> list = jedis.lrange("wonder-list", 0 ,5);
        for(int i=0; i<list.size(); i++) {
            System.out.println("Stored string in redis:: "+list.get(i));
        }
        // 释放对象池
        JedisConfig.pool.close();
    }

    @Test
    public void testByXml(){
        System.out.println("下面是通过xml配置获取redis pool中对象，然后获取数据：");
        List list = redisTemplet.lGet("wonder-list",0,5);
        System.out.println(list);
    }
}

通过程序与之前的一致通过xml的测试输出如下：

21:03:39.312 [main] DEBUG org.springframework.beans.factory.support.DefaultListableBeanFactory - Returning cached instance of singleton bean 'org.springframework.boot.test.mock.mockito.MockitoBeans'
下面是通过xml配置获取redis pool中对象，然后获取数据：
21:03:39.363 [main] DEBUG org.springframework.data.redis.core.RedisConnectionUtils - Opening RedisConnection
[Mysql, Mongodb, Redis, Mysql, Mongodb, Redis]

项目目录结构如下：

如图