springboot cache缓存实例demo

记在前面：

@Cacheable@CachePut存入缓存里面的数据是方法执行的返回值

所以加了@CachePut的类的返回值要和加了@Cacheable的类的返回值一样

我的环境：

springboot2.x，idea

目录结构

mysql里面的表结构

CREATE TABLE `user` (
  `id` int(30) NOT NULL AUTO_INCREMENT,
  `username` varchar(30) DEFAULT NULL,
  `password` varchar(30) DEFAULT NULL,
  PRIMARY KEY (`id`)
)

配置文件application.properties

server.port=8181
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/cache?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=123456

View Code

pom.xml

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.swd</groupId>
    <artifactId>mydemo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>mydemo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <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>2.1.1</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.10</version>
        </dependency>

    </dependencies>

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

</project>

View Code

启动类

package com.swd.mydemo;

import org.apache.ibatis.annotations.Mapper;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;

@SpringBootApplication
@EnableCaching
@MapperScan("com.swd.mydemo.dao")
public class MydemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(MydemoApplication.class, args);
    }

}

View Code

controller层

package com.swd.mydemo.controller;

import com.swd.mydemo.bean.User;
import com.swd.mydemo.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

/**
 * @program: mydemo
 * @Date: 2019/12/25 14:36
 * @Author: lhh
 * @Description:
 */
@RestController
public class controller {

    @Autowired
    UserService userService;

    @GetMapping("user/{id}")
    public User getUserById(@PathVariable("id") Integer id)
    {
        return userService.getUserById(id);
    }

    @GetMapping("user")
    public void updateUserById(User user)
    {
        userService.updateUserById(user);
    }

}

bean层

package com.swd.mydemo.bean;

import lombok.Data;

/**
 * @program: mydemo
 * @Date: 2019/12/25 14:30
 * @Author: lhh
 * @Description:
 */
@Data
public class User {
    private int id;
    private String username;
    private String password;
}

service层

package com.swd.mydemo.service;

import com.swd.mydemo.bean.User;
import com.swd.mydemo.dao.UserDao;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CachePut;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;

/**
 * @program: mydemo
 * @Date: 2019/12/25 14:34
 * @Author: lhh
 * @Description:
 */
@Service
public class UserService {

    @Autowired
    UserDao userDao;

    @Cacheable(cacheNames = "userw",key = "#id")//key里面的id取得是参数id（url传过来的是1） 
    public User getUserById(Integer id)
    {
        System.out.println("查询"+id+"员工");
        User user = userDao.getById(id);
        return user;
    }

    @CachePut(cacheNames = "userw",key = "#result.id")//result.id和user.id都可以（user.id是1）
    public User updateUserById(User user)
    {
        System.out.println("更新"+user.getId()+"员工"+user.getUsername());
        userDao.updateById(user);
        return user;
    }
}

在chrome中测试

在chrome多点几次回车查询，在idea控制台里面，public User getUserById(Integer id)这个方法只执行了一次，其他都是从缓存里面取的结果到chrome界面里

更新

页面没报错，控制台显示更新成功

结果：

数据库表里面更新成功

缓存更新成功，页面取的数据是从已经更新了的缓存里面取出来的

在来看idea控制台，可见从数据库里面查数据只查询了一次，其他都是从缓存里面查询出来的，牛皮！！

下个博客可以将写一个redis和cache在一起在一起的小例子，就从这个例子改。如果方便请点个赞呀，兄弟们。看在我讲的这么详细的份上。想要源码的可以留言评论哦。

springboot cache缓存实例demo

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