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);
     }
 }

SpringBootDemoApplicationTests