Springboot2.0访问Redis集群

Redis 是一个开源（BSD许可）的，内存中的数据结构存储系统，它可以用作高性能的key-value数据库、缓存和消息中间件，掌握它是程序员的必备技能，下面是一个springboot访问redis的demo。

新建一个springboot项目，这里取名spring-boot-demo

项目结构目录如下

pom.xml文件内容

<?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.carry</groupId>
    <artifactId>spring-boot-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>spring-boot-demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.2.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>
        <mybatis.version>1.3.2</mybatis.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>${mybatis.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-pool2</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <fork>true</fork>
                </configuration>
            </plugin>
        </plugins>
    </build>


</project>

下面我们来配置redis，因为需要用到mysql数据库，这里使用mybatis访问

application.yml文件内容

#mybatis配置
mybatis:
  mapper-locations: classpath:mapper/*Mapper.xml
  type-aliases-package: com.carry.domain
#数据源
spring:
  datasource:
    url: jdbc:mysql://192.168.68.100:3306/test
    driver-class-name: com.mysql.jdbc.Driver
    username: root
    password: 123456
  #jackson时间格式化
  jackson:
    time-zone: GMT+8
    date-format: yyyy-MM-dd HH:mm:ss
  #redis配置
  redis:
    cluster:
      nodes: 192.168.68.100:7000,192.168.68.100:7001,192.168.68.101:7000,192.168.68.101:7001,192.168.68.102:7000,192.168.68.102:7001
    timeout: 6000ms
    password: 123456
    lettuce:
      pool:
        max-active: 8
        max-wait: -1ms
        max-idle: 8
        min-idle: 0
    database: 0

新建文件RedisConfig.java，内容如下

package com.carry.config;

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;

@Configuration
@AutoConfigureAfter(RedisAutoConfiguration.class)
public class RedisConfig {

    @Bean
    public RedisTemplate<String, Object> redisCacheTemplate(LettuceConnectionFactory redisConnectionFactory) {
        //redis序列化器
        Jackson2JsonRedisSerializer<Object> jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer<>(Object.class);
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);
        RedisTemplate<String, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(redisConnectionFactory);
        template.setKeySerializer(jackson2JsonRedisSerializer);
        template.setValueSerializer(jackson2JsonRedisSerializer);
        template.setHashKeySerializer(jackson2JsonRedisSerializer);
        template.setHashValueSerializer(jackson2JsonRedisSerializer);
        return template;
    }
}

最后在项目启动类SpringBootDemoApplication上加上注解@EnableCaching开启缓存

配置至此结束，下面我们来通过代码来访问redis集群

先写一个访问mysql的mapper，其中只包含一个方法List<User> findAll();

对应SQL语句为select * from user

User实体类跟user表字段一一对应

UserServiceImpl代码内容

package com.carry.service.impl;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;

import com.carry.domain.User;
import com.carry.mapper.UserMapper;
import com.carry.service.UserService;

@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;

    @Cacheable(value = "findAll", key = "'test'")
    public List<User> findAll() {
        System.out.println("如果没打印这句话，说明走了缓存！");
        return userMapper.findAll();
    }
}

UserController代码内容

package com.carry.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import com.carry.domain.User;
import com.carry.service.UserService;

@RestController
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping("/getUsers")
    public List<User> getUsers(){
        return userService.findAll();
    }

}

最后启动项目在浏览器中访问http://localhost:8080/getUsers

第一次访问控制台输出“如果没打印这句话，说明走了缓存！”

再次访问控制台则没有输出。

我们通过redis-cli连接redis会发现key值是一个很奇怪的值

其实就是我们在@Cacheable注解配的值拼起来的

需要注意的是key的值需要用单引号''引起来不然会报错

 最后写了几个test case，读者自己去运行看看控制台会输出什么

package com.carry;

import java.util.Date;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.stream.IntStream;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.redis.core.Cursor;
import org.springframework.data.redis.core.DefaultTypedTuple;
import org.springframework.data.redis.core.HashOperations;
import org.springframework.data.redis.core.ListOperations;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.ScanOptions;
import org.springframework.data.redis.core.SetOperations;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.test.context.junit4.SpringRunner;

import com.carry.domain.User;

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringBootDemoApplicationTests {

    private static final Logger log = LoggerFactory.getLogger(SpringBootDemoApplicationTests.class);


    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @Autowired
    private RedisTemplate<String, Object> redisCacheTemplate;


    @Test
    public void redisTest() {
        ExecutorService executorService = Executors.newFixedThreadPool(1000);
        IntStream.range(0, 1000).forEach(i ->
                executorService.execute(() -> stringRedisTemplate.opsForValue().increment("kk", 1))
        );
    }

    @Test
    public void redisTestString() {
        stringRedisTemplate.opsForValue().set("carry", "chan");
        final String v1 = stringRedisTemplate.opsForValue().get("carry");
        log.info("[字符缓存结果] - [{}]", v1);
    }

    @Test
    public void redisTestObject() {
        //以下只演示整合，具体Redis命令可以参考官方文档，Spring Data Redis 只是改了个名字而已，Redis支持的命令它都支持
        String key = "carry:user:1";
        ValueOperations<String, Object> valueOperations = redisCacheTemplate.opsForValue();
        valueOperations.set(key, new User(1, "carry", new Date(), "longhua"));
        //对应 String（字符串）
        final User user = (User) valueOperations.get(key);
        log.info("[对象缓存结果] - [{}]", user);
    }

    @Test
    public void redisTestList() {
        ListOperations<String, Object> listOperations = redisCacheTemplate.opsForList();
        listOperations.trim("key1", 1, 0);
        List<Object> list = listOperations.range("key1", 0, -1);
        log.info("[对象缓存结果] - {}", list);
        listOperations.leftPush("key1", 1);
        listOperations.leftPush("key1", 2);
        listOperations.rightPush("key1", 3);
        list = listOperations.range("key1", 0, -1);
        log.info("[对象缓存结果] - {}", list);
    }

    @Test
    public void redisTestHash() {
        HashOperations<String, Object, Object> hashOperations = redisCacheTemplate.opsForHash();
        hashOperations.put("hkey", "k1", "v1");
        hashOperations.put("hkey", "k2", "v2");
        hashOperations.put("hkey", "k3", "v3");
        Map<Object, Object> map = hashOperations.entries("hkey");
        log.info("[对象缓存结果] - [{}]", map);
    }

    @Test
    public void redisTestSet() {
        SetOperations<String, Object> setOperations = redisCacheTemplate.opsForSet();
        setOperations.add("skey", "v1", "v2", "v3", "v4");
        Cursor<Object> cursor = setOperations.scan("skey", ScanOptions.NONE);
        while (cursor.hasNext()) {
            System.out.println(cursor.next());
        }
        log.info("[对象缓存结果] - [{}]", cursor);
    }

    @Test
    public void redisTestZSet() {
        ZSetOperations<String, Object> zSetOperations = redisCacheTemplate.opsForZSet();
        ZSetOperations.TypedTuple<Object> tuple1 = new DefaultTypedTuple<>("v1", 9.6);
        ZSetOperations.TypedTuple<Object> tuple2 = new DefaultTypedTuple<>("v2", 9.9);
        Set<ZSetOperations.TypedTuple<Object>> tuples = new HashSet<>();
        tuples.add(tuple1);
        tuples.add(tuple2);
        zSetOperations.add("zkey", tuples);
        Set<Object> set = zSetOperations.range("zkey", 0, -1);
        log.info("[对象缓存结果] - {}", set);
    }
}