实战springboot集成Redis内存缓存数据库，小白也能懂

 

文章目录

• • • 一、基本概况
    • 二、搭建Redis环境
    • 三、新建SpringBoot项目
    • 四、使用StringRedisTemplate操作Redis
    • 五、使用RedisTemplate操作Redis
    • 六、总结

 

一、基本概况

为什么使用缓存

• 缓存是在内存中存储的数据备份，当数据没有发生本质变化时
• 就可以直接从内存中查询数据，而不用去数据库查询(在磁盘中)
• CPU读取内存的速度要比读取磁盘快，可以提高效率

Redis缓存

• Remote Dictionnary Server(远程数据服务)，是一款内存高速缓存数据库。
• 五种常用数据类型： String（字符串）、List(列表)、Set(集合)、Hash(散列)、ZSet(有序集合)
• 可持久化：一边运行，一边向硬盘备份一份，防止断电等偶然情况，导致内存中数据丢失

二、搭建Redis环境

1.下载Redis

在github上Redis已经停更了，在网上参考了一个链接
链接：https://pan.baidu.com/s/1q8Xg4aG1YEGepl6kc6uP-Q 提取码：os8a

2.设置Redis开机自启

在解压好的文件夹下输入cmd命令

window下安装Redis服务

redis-server --service-install redis.windows.conf

 

检查安装是否成功
搜索服务

点击设置为开机自启

三、新建SpringBoot项目

新建好项目的童鞋可以自动跳过



添加web依赖

选择数据库依赖

选择项目位置，点击finish

四、使用StringRedisTemplate操作Redis

1.pom.xml文件引入坐标

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

 

2.在appliaction.properties配置redis数据库连接信息

#redis配置
#Redis服务器地址
spring.redis.host=127.0.0.1
#Redis服务器连接端口
spring.redis.port=6379
#Redis数据库索引（默认为0）
spring.redis.database=0  

 

3.在SpringbootdemoApplicationTests中测试操作Redis

@SpringBootTest
class SpringbootdemoApplicationTests {

<span >@Autowired</span>
StringRedisTemplate stringRedisTemplate<span >;</span> <span >//操作key-value都是字符串，最常用</span>

<span >@Test</span>
<span >public</span> <span >void</span> <span >test01</span><span >(</span><span >)</span><span >{</span>
    <span >//字符串操作</span>
    stringRedisTemplate<span >.</span><span >opsForValue</span><span >(</span><span >)</span><span >.</span><span >append</span><span >(</span><span >"msg"</span><span >,</span><span >"coder"</span><span >)</span><span >;</span>

    <span >//列表操作</span>
    stringRedisTemplate<span >.</span><span >opsForList</span><span >(</span><span >)</span><span >.</span><span >leftPush</span><span >(</span><span >"mylist"</span><span >,</span><span >"1"</span><span >)</span><span >;</span>
    stringRedisTemplate<span >.</span><span >opsForList</span><span >(</span><span >)</span><span >.</span><span >leftPush</span><span >(</span><span >"mylist"</span><span >,</span><span >"2"</span><span >)</span><span >;</span>
<span >}</span>

}

 

对于Redis的五大常用数据类型都提供了方法

String（字符串）、List(列表)、Set(集合)、Hash(散列)、ZSet(有序集合)
stringRedisTemplate.opsForValue();[String(字符串)]
stringRedisTemplate.opsForList();[List(列表)]
stringRedisTemplate.opsForSet();[Set(集合)]
stringRedisTemplate.opsForHash();[Hash(散列)]
stringRedisTemplate.opsForZSet();[ZSet(有序集合)]

使用RedisDesktopManager可视化工具查看结果

StringTemplate类中方法存取的key-value值是String类型，RedisTemplate中key-value值是Object类型，RedisTemplate是StringTemplate父类

下面就用RedisTemplate实现从MySQL数据库取出数据放到Redis缓存

五、使用RedisTemplate操作Redis

1.项目目录结构

2.建立与数据库相关的类

建表的sql脚本

CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(32) NOT NULL COMMENT '用户名称',
  `birthday` datetime DEFAULT NULL COMMENT '生日',
  `sex` char(1) DEFAULT NULL COMMENT '性别',
  `address` varchar(256) DEFAULT NULL COMMENT '地址',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=49 DEFAULT CHARSET=utf8;

 

application.properties配置文件

• MySQL及Redis连接的相关配置

#MySQL的配置
spring.datasource.url= jdbc:mysql://localhost:3306/selfproj?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

#设置访问端口号
server.port = 8099

#redis配置
#Redis服务器地址
spring.redis.host=127.0.0.1
#Redis服务器连接端口
spring.redis.port=6379
#Redis数据库索引（默认为0）
spring.redis.database=0

 

User类

• 采用ORM思想，属性和数据库字段对应

package com.thinkcoder.bean;

import java.io.Serializable;
import java.util.Date;

/**

• @ClassName User

• @Author Think-Coder

• @Data 2020/5/27 10:35

• @Version 1.0
  */
  public class User implements Serializable {
  private Integer id;
  private String username;
  private Date birthday;
  private String sex;
  private String address;

  //getter和setter方法
  public Integer getId() {return id;}
  public void setId(Integer id) {this.id = id;}
  public String getUsername() {return username;}
  public void setUsername(String username) {this.username = username;}
  public Date getBirthday() {return birthday;}
  public void setBirthday(Date birthday) {this.birthday = birthday;}
  public String getSex() {return sex;}
  public void setSex(String sex) {this.sex = sex;}
  public String getAddress() {return address;}
  public void setAddress(String address) {this.address = address;}

  //重写toString方法
  @Override
  public String toString() {
  return “User{” +
  “id=” + id +
  “, username=’” + username + ‘’’ +
  “, birthday=” + birthday +
  “, sex=’” + sex + ‘’’ +
  “, address=’” + address + ‘’’ +
  ‘}’;
  }
  }

 

UserMapper类

• 使用注解方法操作数据库

@Mapper
public interface UserMapper {
    @Select("SELECT * FROM user WHERE id = #{id}")
    User findById(int id);
}

 

3.MyRedisConfig

自定义序列化类，将存储在Redis的对象序列化为json格式，不会产生乱码

@Configuration
@EnableAutoConfiguration
public class MyRedisConfig {
    @Bean
    public RedisTemplate<Object, User> redisTemplate(RedisConnectionFactory redisConnectionFactory){
        RedisTemplate<Object, User> template = new RedisTemplate<>();
        template.setConnectionFactory(redisConnectionFactory);

    Jackson2JsonRedisSerializer<span ><span >&lt;</span>User<span >&gt;</span></span> ser <span >=</span> <span >new</span> <span >Jackson2JsonRedisSerializer</span><span >&lt;</span><span >&gt;</span><span >(</span>User<span >.</span><span >class</span><span >)</span><span >;</span>
    template<span >.</span><span >setDefaultSerializer</span><span >(</span>ser<span >)</span><span >;</span>
    <span >return</span> template<span >;</span>
<span >}</span>

}

 

4.工具类RedisUtil类

//工具类中使用Autowired注解需要加上Compoent
@Component
public class RedisUtil {
    @Autowired
    RedisTemplate redisTemplate;   //key-value是对象的

<span >//判断是否存在key</span>
<span >public</span>  <span >boolean</span> <span >hasKey</span><span >(</span>String key<span >)</span><span >{</span>
    <span >return</span> redisTemplate<span >.</span><span >hasKey</span><span >(</span>key<span >)</span><span >;</span>
<span >}</span>

<span >//从redis中获取值</span>
<span >public</span>  Object <span >get</span><span >(</span>String key<span >)</span><span >{</span>
    <span >return</span>  redisTemplate<span >.</span><span >opsForValue</span><span >(</span><span >)</span><span >.</span><span >get</span><span >(</span>key<span >)</span><span >;</span>
<span >}</span>

<span >//向redis插入值</span>
<span >public</span>  <span >boolean</span> <span >set</span><span >(</span><span >final</span> String key<span >,</span>Object value<span >)</span><span >{</span>
    <span >boolean</span> result <span >=</span> <span >false</span><span >;</span>
    <span >try</span><span >{</span>
         redisTemplate<span >.</span><span >opsForValue</span><span >(</span><span >)</span><span >.</span><span >set</span><span >(</span>key<span >,</span>value<span >)</span><span >;</span>
        result <span >=</span> <span >true</span><span >;</span>
    <span >}</span><span >catch</span> <span >(</span><span >Exception</span> e<span >)</span><span >{</span>
        e<span >.</span><span >printStackTrace</span><span >(</span><span >)</span><span >;</span>
    <span >}</span>
    <span >return</span>  result<span >;</span>
<span >}</span>

}

 

5.sevice包代码

IUserService

@Service
public interface IUserService {
	//根据id查用户信息
    User findById(int id);
}

 

UserService实现类

@Service
public class UserServiceImpl implements IUserService {
    User user;
    @Autowired
    UserMapper userMapper;

<span >@Autowired</span>
<span >private</span>  RedisUtil redisUtil<span >;</span>

<span >@Override</span>
<span >public</span> User <span >findById</span><span >(</span><span >int</span> id<span >)</span> <span >{</span>
    String key <span >=</span> <span >"user"</span><span >+</span>id<span >;</span>
    <span >if</span><span >(</span>redisUtil<span >.</span><span >hasKey</span><span >(</span>key<span >)</span><span >)</span> <span >{</span>
        user <span >=</span> <span >(</span>User<span >)</span>redisUtil<span >.</span><span >get</span><span >(</span>key<span >)</span><span >;</span>
        System<span >.</span>out<span >.</span><span >println</span><span >(</span><span >"查询的是缓存"</span><span >)</span><span >;</span>
    <span >}</span><span >else</span><span >{</span>
        user <span >=</span> userMapper<span >.</span><span >findById</span><span >(</span>id<span >)</span><span >;</span>
        System<span >.</span>out<span >.</span><span >println</span><span >(</span><span >"查询的是数据库"</span><span >)</span><span >;</span>
        System<span >.</span>out<span >.</span><span >println</span><span >(</span>redisUtil<span >.</span><span >set</span><span >(</span>key<span >,</span>user<span >)</span> <span >?</span> <span >"插入成功"</span> <span >:</span> <span >"插入失败"</span><span >)</span><span >;</span>
    <span >}</span>
    <span >return</span> user<span >;</span>
<span >}</span>

}

 

6.UserController类

@RestController
public class UserController {
    @Autowired
    IUserService userService;

<span >@GetMapping</span><span >(</span><span >"/user/{id}"</span><span >)</span>
<span >public</span> User <span >findById</span><span >(</span><span >@PathVariable</span><span >(</span><span >"id"</span><span >)</span> Integer id<span >)</span><span >{</span>
    User user <span >=</span> userService<span >.</span><span >findById</span><span >(</span>id<span >)</span><span >;</span>
    <span >return</span> user<span >;</span>
<span >}</span>

}

 

7.测试

打开浏览器输入下方url

查看控制台输出

Redis Desktop Manager显示结果

六、总结

整体来说，操作Redis是两个类，RedisTemplate类和StringTemplate类，为父子关系，提供的方法正好对应操作Redis数据类型的指令，所以要把数据类型及常用的指令练熟。

在实际业务中Redis的应用不止这些，继续探索吧

---

-END-

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文章目录

• • • 一、基本概况
    • 二、搭建Redis环境
    • 三、新建SpringBoot项目
    • 四、使用StringRedisTemplate操作Redis
    • 五、使用RedisTemplate操作Redis
    • 六、总结

 

一、基本概况

为什么使用缓存

• 缓存是在内存中存储的数据备份，当数据没有发生本质变化时
• 就可以直接从内存中查询数据，而不用去数据库查询(在磁盘中)
• CPU读取内存的速度要比读取磁盘快，可以提高效率

Redis缓存

• Remote Dictionnary Server(远程数据服务)，是一款内存高速缓存数据库。
• 五种常用数据类型： String（字符串）、List(列表)、Set(集合)、Hash(散列)、ZSet(有序集合)
• 可持久化：一边运行，一边向硬盘备份一份，防止断电等偶然情况，导致内存中数据丢失

二、搭建Redis环境

1.下载Redis

在github上Redis已经停更了，在网上参考了一个链接
链接：https://pan.baidu.com/s/1q8Xg4aG1YEGepl6kc6uP-Q 提取码：os8a

2.设置Redis开机自启

在解压好的文件夹下输入cmd命令

window下安装Redis服务

redis-server --service-install redis.windows.conf

 

检查安装是否成功
搜索服务

点击设置为开机自启

三、新建SpringBoot项目

新建好项目的童鞋可以自动跳过



添加web依赖

选择数据库依赖

选择项目位置，点击finish

四、使用StringRedisTemplate操作Redis

1.pom.xml文件引入坐标

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

 

2.在appliaction.properties配置redis数据库连接信息

#redis配置
#Redis服务器地址
spring.redis.host=127.0.0.1
#Redis服务器连接端口
spring.redis.port=6379
#Redis数据库索引（默认为0）
spring.redis.database=0  

 

3.在SpringbootdemoApplicationTests中测试操作Redis

@SpringBootTest
class SpringbootdemoApplicationTests {

<span >@Autowired</span>
StringRedisTemplate stringRedisTemplate<span >;</span> <span >//操作key-value都是字符串，最常用</span>

<span >@Test</span>
<span >public</span> <span >void</span> <span >test01</span><span >(</span><span >)</span><span >{</span>
    <span >//字符串操作</span>
    stringRedisTemplate<span >.</span><span >opsForValue</span><span >(</span><span >)</span><span >.</span><span >append</span><span >(</span><span >"msg"</span><span >,</span><span >"coder"</span><span >)</span><span >;</span>

    <span >//列表操作</span>
    stringRedisTemplate<span >.</span><span >opsForList</span><span >(</span><span >)</span><span >.</span><span >leftPush</span><span >(</span><span >"mylist"</span><span >,</span><span >"1"</span><span >)</span><span >;</span>
    stringRedisTemplate<span >.</span><span >opsForList</span><span >(</span><span >)</span><span >.</span><span >leftPush</span><span >(</span><span >"mylist"</span><span >,</span><span >"2"</span><span >)</span><span >;</span>
<span >}</span>