Springboot使用MybatisPlus实现Cache缓存

客官°小女子只卖身不卖艺 2023-02-20 10:50 35阅读 0赞

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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>2.3.1.RELEASE</version>
            <relativePath/> 
        </parent>
        <groupId>com.frank</groupId>
        <artifactId>cache</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>cache-demo</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.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>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.47</version>
            </dependency>
    
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>3.0.5</version>
            </dependency>
        </dependencies>
    
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    
    </project>

application.properties

spring.datasource.url= jdbc:mysql://localhost:3306/cache-db?useUnicode=true&useSSL=false&characterEncoding=utf8&serverTimezone=Asia/Shanghai
    spring.datasource.username= root
    spring.datasource.password= 123456
    spring.datasource.driver-class-name= com.mysql.jdbc.Driver
    
    
    mybatis-plus.mapper-locations= classpath:mapper/*Mapper.xml

ArticleController

package com.frank.cache.controller;
    
    import com.frank.cache.entity.Article;
    import com.frank.cache.entity.ResultVo;
    import com.frank.cache.mapper.ArticleMapper;
    import com.frank.cache.service.ArticleService;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.*;
    
    import java.util.List;
    
    /**
     * @author 小石潭记
     * @date 2020/6/26 11:30
     * @Description: ${todo}
     */
    @RestController
    @Slf4j
    public class ArticleController {
        @Autowired
        private ArticleService articleService;
    
        @Autowired
        ArticleMapper articleMapper;
    
        /**
         * 添加文章
         */
        @PostMapping("/add")
        public ResultVo addArticle(@RequestBody Article article) {
            log.info(article.toString());
            Integer result = articleService.addArticle(article);
            if (result >= 0) {
                return ResultVo.success(article);
            }
            return ResultVo.fail();
        }
    
        /**
         * 获取一篇文章
         */
        @GetMapping("/get")
        public ResultVo getArticle(@RequestParam("id") Integer id) {
            Long start = System.currentTimeMillis();
            Article article = articleService.getArticle(id);
            Long end = System.currentTimeMillis();
            log.info("耗时："+ (end-start));
            if (null != article)
                return ResultVo.success(article);
            return ResultVo.fail();
        }
    
        @GetMapping("/getAll")
        public ResultVo getAllArticle() {
            Long start = System.currentTimeMillis();
            List<Article> articles = articleService.getAllArticles();
            Long end = System.currentTimeMillis();
            log.info("耗时："+(end-start));
            if (null != articles) {
                return ResultVo.success(articles);
            }
            return ResultVo.fail();
        }
    
        /**
         * 更新一篇文章
         */
        @GetMapping("/resh")
        public ResultVo update(@RequestParam("content") String contetnt, @RequestParam("id") Integer id) {
            final Integer result = articleService.updateContentById(contetnt, id);
            if (result > 0) {
                return ResultVo.success(result);
            } else {
                return ResultVo.fail();
            }
        }
    
        /**
         * 删除一篇文章
         */
        @GetMapping("/rem")
        public ResultVo remove(@RequestParam("id") Integer id) {
            final Integer result = articleService.removeArticleById(id);
            if (result > 0) {
                return ResultVo.success(result);
            } else {
                return ResultVo.fail();
            }
        }
    }

Article

package com.frank.cache.entity;
    
    import lombok.Data;
    
    /**
     * @author 小石潭记
     * @date 2020/6/26 11:20
     * @Description: ${todo}
     */
    @Data
    public class Article {
        private int id;
        private String title;
        private String content;
        private String author;
        private String fileName;
        private String state;
    }

ResultVo

package com.frank.cache.entity;
    
    import lombok.Data;
    
    /**
     * @author 小石潭记
     * @date 2020/6/26 11:32
     * @Description: ${todo}
     */
    @Data
    public class ResultVo {
        private int code;
        private String message;
        private Object data;
    
        public static ResultVo success(Object object){
            ResultVo resultVo = new ResultVo();
            resultVo.setCode(200);
            resultVo.setMessage("success");
            resultVo.setData(object);
            return resultVo;
        }
    
        public static ResultVo fail(){
            ResultVo resultVo = new ResultVo();
            resultVo.setCode(404);
            resultVo.setMessage("fail");
            resultVo.setData(null);
            return resultVo;
        }
    }

ArticleMapper

package com.frank.cache.mapper;
    
    import com.baomidou.mybatisplus.core.mapper.BaseMapper;
    import com.frank.cache.entity.Article;
    
    import java.util.List;
    
    /**
     * @author 小石潭记
     * @date 2020/6/26 11:23
     * @Description: ${todo}
     */
    public interface ArticleMapper extends BaseMapper<Article> {
        /**
         * 自定义sql查询
         */
        List<Article> getAllArticles();
    }

ArticleService

package com.frank.cache.service;
    
    import com.frank.cache.entity.Article;
    import com.frank.cache.mapper.ArticleMapper;
    import lombok.extern.slf4j.Slf4j;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.cache.annotation.CacheConfig;
    import org.springframework.cache.annotation.CacheEvict;
    import org.springframework.cache.annotation.CachePut;
    import org.springframework.cache.annotation.Cacheable;
    import org.springframework.stereotype.Service;
    
    import java.util.List;
    import java.util.concurrent.atomic.AtomicInteger;
    
    /**
     * @author 小石潭记
     * @date 2020/6/26 11:27
     * @Description: service层引入cache缓存
     */
    @Service
    @CacheConfig(cacheNames = "articleCache")
    @Slf4j
    public class ArticleService {
    
        private AtomicInteger count =new AtomicInteger(0);
    
        @Autowired
        private ArticleMapper articleMapper;
    
        /**
         * 增加一篇文章 每次就进行缓存
         * @return
         */
        @CachePut
        public Integer addArticle(Article article){
            int insert = articleMapper.insert(article);
            if (insert>0) {
                return insert;
            }
            return null;
        }
    
        /**
         * 获取文章  以传入的id为键，当state为0的时候不进行缓存
         * @param id 文章id
         * @return
         */
        @Cacheable(key = "#id",unless = "#result.state==0")
        public Article getArticle(Integer id) {
            try {
                //模拟耗时操作
                Thread.sleep(5000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            Article article = articleMapper.selectById(id);
            log.info("--执行数据库查询操作"+count.incrementAndGet()+"次"+"id:"+id);
            return article;
        }
    
        /**
         * 自定义的sql方法
         * @return
         */
        @Cacheable()
        public List<Article> getAllArticles() {
            try {
                //模拟耗时操作
                Thread.sleep(5000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            List<Article> allArticles = articleMapper.getAllArticles();
            return allArticles;
        }
    
        /**
         * 通过id更新内容 清除以id作为键的缓存
         *
         * @param id
         * @return
         */
        @CacheEvict(key = "#id")
        public Integer updateContentById(String content, Integer id) {
            Article article = articleMapper.selectById(id);
            article.setContent(content);
            int result = articleMapper.updateById(article);
            log.info("--执行更新操作id:--"+id);
            return result;
        }
    
        /**
         * 通过id移除文章
         * @param id  清除以id作为键的缓存
         * @return
         */
        @CacheEvict(key = "#id")
        public Integer removeArticleById(Integer id){
            int result = articleMapper.deleteById(id);
            log.info("执行删除操作,id:"+id);
            return result;
        }
    }

CacheDemoApplication

package com.frank.cache;
    
    import org.mybatis.spring.annotation.MapperScan;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cache.annotation.EnableCaching;
    import org.springframework.context.annotation.ComponentScan;
    
    @SpringBootApplication
    @EnableCaching
    @MapperScan(basePackages = {"com.frank.cache"})
    public class CacheDemoApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(CacheDemoApplication.class, args);
        }
    
    }

ArticleMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org/DTD Mapper 3.0//EN" "mybatis-3-mapper.dtd">
    <mapper namespace="com.frank.cache.mapper.ArticleMapper">
        <select id="getAllArticles" resultType="com.frank.cache.entity.Article">
            select * from article
        </select>
    
        
        
        <resultMap id="myArticle" type="com.frank.cache.entity.Article">
            <id column="id" property="id" />
            <result column="title" property="title" />
            <result column="content" property="content" />
            <result column="author" property="author" />
            <result column="fileName" property="file_name" />
            <result column="state" property="state" />
        </resultMap>
    
    </mapper>

db.sql

CREATE TABLE Article
    (
      `id`        int(11)                                              NOT NULL AUTO_INCREMENT,
      `title`     varchar(30) CHARACTER SET gbk COLLATE gbk_chinese_ci NULL DEFAULT NULL,
      `author`    varchar(30) CHARACTER SET gbk COLLATE gbk_chinese_ci NULL DEFAULT NULL,
      `content`   mediumtext CHARACTER SET gbk COLLATE gbk_chinese_ci  NULL,
      `file_name` varchar(30) CHARACTER SET gbk COLLATE gbk_chinese_ci NULL DEFAULT NULL,
      `state`     smallint(2)                                          NULL DEFAULT 1 COMMENT '状态',
      PRIMARY KEY (`id`)
    )
      ENGINE = InnoDB
      DEFAULT CHARACTER SET = gbk
      COLLATE = gbk_chinese_ci
      AUTO_INCREMENT = 11
      ROW_FORMAT = COMPACT;

# Cache Started
    
    * @CacheConfig
    这个注解的的主要作用就是全局配置缓存，比如配置缓存的名字（cacheNames),只需要在类上配置一次，下面的方法就默认以全局配置为主，不需要二次配置，节省了部分代码。
    
    * @Cacheable
    这个注解是最重要的,主要实现的功能再进行一个读操作的时候。就是先从缓存中查询，如果查找不到，就会走数据库的执行方法，这是缓存的注解最重要的一个方法，基本上我们的所有缓存实现都要依赖于它。它具有的属性为cacheNames:缓存名字，condtion：缓存的条件，unless:不缓存的条件。可以指定SPEL表达式来实现,也可以指定缓存的key，缓存的内部实现一般都是key,value形式，类似于一个Map（实际上cacheable的缓存的底层实现就是concurrenHashMap）,指定了key，那么缓存就会以key作为键，以方法的返回结果作为值进行映射。
    
    * @CacheEvict
    这个注解主要是配合@Cacheable一起使用的，它的主要作用就是清除缓存，当方法进行一些更新、删除操作的时候，这个时候就要删除缓存。如果不删除缓存，就会出现读取不到最新缓存的情况，拿到的数据都是过期的。它可以指定缓存的key和conditon，它有一个重要的属性叫做allEntries默认是false,也可以指定为true,主要作用就是清除所有的缓存，而不以指定的key为主。
    
    * @CachePut
    这个注解它总是会把数据缓存，而不会去每次做检查它是否存在，相比之下它的使用场景就比较少，毕竟我们希望并不是每次都把所有的数据都给查出来，我们还是希望能找到缓存的数据，直接返回，这样能提升我们的软件效率。
    
    * @cache
    这个注解它是上面的注解的综合体，包含上面的三个注解（cacheable、cachePut、CacheEvict），可以使用这一个注解来包含上面的所有的注解。
    
    测试：
    http://localhost:8080/add   POST
    {
       "title": "老人与海",
       "content": "老人的线紧牵，爱学习的心，永不变.",
       "author": "海明威",
       "fileName": "老人与海",
       "state": "1"
    }
    
    http://localhost:8080/get?id=1  第一次查询数据库，耗时5028，继续访问该接口则直接读取缓存，耗时非常短。
    
    
    http://localhost:8080/getAll
    
    http://localhost:8080/resh?id=1&content=一本很有意思的书籍
    
    http://localhost:8080/rem?id=2

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