Spring 访问 Redis

# Spring 访问 Redis

# 简介

Redis (opens new window) 是一个被数百万开发人员用作数据库、缓存、流引擎和消息代理的开源内存数据库。

在 Spring 中，spring-data-redis (opens new window) 项目对访问 Redis (opens new window) 进行了 API 封装，提供了便捷的访问方式。 spring-data-redis (opens new window)

spring-boot (opens new window) 项目中的子模块 spring-boot-starter-data-redis (opens new window) 基于 spring-data-redis (opens new window) 项目，做了二次封装，大大简化了 Redis 的相关配置。

# Spring Boot 快速入门

# 引入依赖

在 pom.xml 中引入依赖：

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

# 数据源配置

spring.redis.database = 0
spring.redis.host = localhost
spring.redis.port = 6379
spring.redis.password =

# 定义实体

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;

import java.io.Serializable;

@Data
@ToString
@NoArgsConstructor
@AllArgsConstructor
public class User implements Serializable {

    private static final long serialVersionUID = 4142994984277644695L;

    private Long id;
    private String name;
    private Integer age;
    private String address;
    private String email;

}

# 定义 CRUD 接口

import java.util.Map;

public interface UserService {

    void batchSetUsers(Map<String, User> users);

    long count();

    User getUser(Long id);

    void setUser(User user);

}

# 创建 CRUD 接口实现


import cn.hutool.core.bean.BeanUtil;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;

import java.util.Map;

@Service
public class UserServiceImpl implements UserService {

    public static final String DEFAULT_KEY = "spring:tutorial:user";

    private final RedisTemplate<String, Object> redisTemplate;

    public UserServiceImpl(RedisTemplate<String, Object> redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    @Override
    public void batchSetUsers(Map<String, User> users) {
        redisTemplate.opsForHash().putAll(DEFAULT_KEY, users);
    }

    @Override
    public long count() {
        return redisTemplate.opsForHash().size(DEFAULT_KEY);
    }

    @Override
    public User getUser(Long id) {
        Object obj = redisTemplate.opsForHash().get(DEFAULT_KEY, id.toString());
        return BeanUtil.toBean(obj, User.class);
    }

    @Override
    public void setUser(User user) {
        redisTemplate.opsForHash().put(DEFAULT_KEY, user.getId().toString(), user);
    }

}

# 创建 Application

创建 Application，实例化一个 RedisTemplate 对象。

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Primary;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

@Slf4j
@SpringBootApplication
public class RedisQuickstartApplication {

    @Autowired
    private ObjectMapper objectMapper;

    @Bean
    @Primary
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {

        // 指定要序列化的域，field,get和set,以及修饰符范围，ANY是都有包括private和public
        objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        // // 指定序列化输入的类型，类必须是非final修饰的，final修饰的类，比如String,Integer等会跑出异常
        // objectMapper.activateDefaultTyping(new DefaultBaseTypeLimitingValidator(),
        //     ObjectMapper.DefaultTyping.NON_FINAL);

        // 使用Jackson2JsonRedisSerializer来序列化和反序列化redis的value值（默认使用JDK的序列化方式）
        Jackson2JsonRedisSerializer<Object> serializer = new Jackson2JsonRedisSerializer<>(Object.class);
        serializer.setObjectMapper(objectMapper);

        RedisTemplate<String, Object> template = new RedisTemplate<>();
        // 配置连接工厂
        template.setConnectionFactory(factory);
        // 值采用json序列化
        template.setValueSerializer(serializer);
        // 使用StringRedisSerializer来序列化和反序列化redis的key值
        template.setKeySerializer(new StringRedisSerializer());
        // 设置hash key 和value序列化模式
        template.setHashKeySerializer(new StringRedisSerializer());
        template.setHashValueSerializer(serializer);
        template.afterPropertiesSet();

        return template;
    }

    public static void main(String[] args) {
        SpringApplication.run(RedisQuickstartApplication.class, args);
    }

}

# 测试

@Slf4j
@SpringBootTest(classes = { RedisQuickstartApplication.class })
public class RedisQuickstartTests {

    @Autowired
    private UserService userService;

    @Test
    public void test() {
        final long SIZE = 1000L;
        Map<String, User> map = new HashMap<>();
        for (long i = 0; i < SIZE; i++) {
            User user = new User(i, RandomUtil.randomChineseName(),
                RandomUtil.randomInt(1, 100),
                RandomUtil.randomEnum(Location.class).name(),
                RandomUtil.randomEmail());
            map.put(String.valueOf(i), user);
        }
        userService.batchSetUsers(map);
        long count = userService.count();
        Assertions.assertThat(count).isEqualTo(SIZE);

        for (int i = 0; i < 100; i++) {
            long id = RandomUtil.randomLong(0, 1000);
            User user = userService.getUser(id);
            log.info("user-{}: {}", id, user.toString());
        }
    }

}

# 示例源码

更多 Spring 访问 Redis 示例请参考：Redis 示例源码 (opens new window)

# 参考资料

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#Java #框架 #Spring #SpringBoot #Redis

上次更新: 2024/04/24, 07:33:33

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