Redis在Spring Boot中的应用
最近项目中用到Redis，上网查了很多示例，发现或多或少都有问题。踩过很多坑，终于在Spring Boot中成功实现了Redis存储。记录如下，方便别人，也方便自己。
Redis(REmote DIctionary Server) 是一个由Salvatore Sanfilippo写的key-value存储系统。Redis是一个开源的使用ANSI C语言编写、遵守BSD协议、支持网络、可基于内存亦可持久化的日志型、Key-Value数据库，并提供多种语言的API。它通常被称为数据结构服务器，因为值（value）可以是 字符串(String), 哈希(Map), 列表(list), 集合(sets) 和 有序集合(sorted sets)等类型。
Redis安装
至于在服务器上如何搭建Redis存储系统，本文就不在赘述，网上相关教程很多，请自行Google。如果要实现Redis可远程连接，需要注意一下几点：
- 配置文件redis.conf设置Redis可远程访问
- 设置登录密码
- 设置Redis可在后台运行
- 开启防火墙端口，Redis默认端口为6379
- 建议设置为开机自启动
Spring Boot中Redis应用
1. 引入依赖
pom.xml文件中依赖如下
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
2. 配置文件
可以利用配置文件进行设置，也可以直接通过注释配置。配置文件application.yml如下：
spring:
# REDIS (RedisProperties)
redis:
# Redis服务器地址
host: 192.168.1.197
# Redis服务器连接端口
port: 6379
pool:
# 连接池中的最大空闲连接
max-idle: 8
# 连接池中的最小空闲连接
min-idle: 0
# 连接池最大连接数（使用负值表示没有限制）
max-active: 8
# 连接池最大阻塞等待时间（使用负值表示没有限制）
max-wait: -1
# 连接超时时间（毫秒）
timeout: 0
# Redis数据库索引（默认为0）
database: 0
# Redis服务器连接密码（默认为空）
password: your-password
3. 定义RedisTemplate
package com.ygingko.utest.config;
import com.ygingko.utest.config.redis.RedisObjectSerializer;
import com.ygingko.utest.entity.dto.UserDTO;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.StringRedisSerializer;
import redis.clients.jedis.JedisPoolConfig;
@Configuration
@PropertySource("classpath:application.yml")
public class RedisConfig {
@Value("${spring.redis.host}")
private String host;
@Value("${spring.redis.port}")
private int port;
@Value("${spring.redis.password}")
private String password;
@Value("${spring.redis.database}")
private int database;
@Value("${spring.redis.timeout}")
private int timeout;
@Value("${spring.redis.pool.max-active}")
private int maxActive;
@Value("${spring.redis.pool.max-idle}")
private int maxIdle;
@Value("${spring.redis.pool.min-idle}")
private int minIdle;
@Value("${spring.redis.pool.max-wait}")
private long maxWait;
@Bean
JedisConnectionFactory jedisConnectionFactory() {
JedisConnectionFactory factory = new JedisConnectionFactory();
factory.setHostName(host);
factory.setPort(port);
factory.setPassword(password);
factory.setDatabase(database);
factory.setTimeout(timeout);
JedisPoolConfig jedisPoolConfig = new JedisPoolConfig();
jedisPoolConfig.setMaxTotal(maxActive);
jedisPoolConfig.setMaxIdle(maxIdle);
jedisPoolConfig.setMinIdle(minIdle);
jedisPoolConfig.setMaxWaitMillis(maxWait);
factory.setPoolConfig(jedisPoolConfig);
return factory;
}
@Bean
public RedisTemplate<String, UserDTO> redisTemplate() {
RedisTemplate<String, UserDTO> template = new RedisTemplate<>();
template.setConnectionFactory(jedisConnectionFactory());
template.setKeySerializer(new StringRedisSerializer());
template.setValueSerializer(new RedisObjectSerializer());
return template;
}
}
4. 实现RedisSerializer接口
package com.ygingko.utest.config.redis;
import org.springframework.core.convert.converter.Converter;
import org.springframework.core.serializer.support.DeserializingConverter;
import org.springframework.core.serializer.support.SerializingConverter;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.SerializationException;
public class RedisObjectSerializer implements RedisSerializer {
private Converter<Object, byte[]> serializer = new SerializingConverter();
private Converter<byte[], Object> deserializer = new DeserializingConverter();
private static final byte[] EMPTY_ARRAY = new byte[0];
@Override
public byte[] serialize(Object o) throws SerializationException {
if (o == null) {
return EMPTY_ARRAY;
}
try {
return serializer.convert(o);
} catch (Exception e) {
return EMPTY_ARRAY;
}
}
@Override
public Object deserialize(byte[] bytes) throws SerializationException {
if (isEmpty(bytes)) {
return null;
}
try {
return deserializer.convert(bytes);
} catch (Exception e) {
throw new SerializationException("Cannot deserialize ", e);
}
}
private boolean isEmpty(byte[] data) {
return (data == null || data.length == 0);
}
}
5. 存数对象
存储对象必须实现Serializable接口，有固定的serialVersionUID。如下：
package com.ygingko.utest.entity.dto;
import com.alibaba.fastjson.JSON;
import java.io.Serializable;
public class UserDTO implements Serializable {
private static final long serialVersionUID = 4044555734385804034L;
private Integer uid;
private String name;
private String password;
private Integer level;
public Integer getUid() {
return uid;
}
public void setUid(Integer uid) {
this.uid = uid;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public Integer getLevel() {
return level;
}
public void setLevel(Integer level) {
this.level = level;
}
@Override
public String toString() {
return JSON.toJSONString(this);
}
}
6. 应用示例
package com.ygingko.utest;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.test.context.junit4.SpringRunner;
import redis.clients.jedis.Jedis;
import java.util.ArrayList;
import java.util.List;
@RunWith(SpringRunner.class)
@SpringBootTest
public class UtestApplicationTests {
@Autowired
private RedisTemplate<String, UserDTO> redisTemplate;
@Test
public void testRedis() throws Exception {
UserDTO userBean = new UserDTO();
userBean.setUid(1001);
userBean.setName("huang");
userBean.setLevel(1);
redisTemplate.opsForValue().set("token", userBean);
System.out.println(redisTemplate.opsForValue().get("token"));
}
@Test
public void contextLoads() {
Jedis jedis = new Jedis("192.168.1.197", 6379);
System.out.println("****************" + jedis.ping());
}
}
