SpringBoot使用Redis做缓存，@Cacheable、@CachePut、@CacheEvict等注解的使用

太过爱你忘了你带给我的痛 2022-05-29 20:40 251阅读 0赞

## SpringBoot使用Redis做缓存，@Cacheable、@CachePut、@CacheEvict等注解的使用 ##

#### 导入依赖 ####

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

#### 配置文件 ####

# Redis数据库索引（默认为0）
    spring.redis.database=0
    # Redis服务器地址
    spring.redis.host=192.168.142.142
    # Redis服务器连接端口
    spring.redis.port=6379
    # Redis服务器连接密码（默认为空）
    spring.redis.password=
    # 连接池最大连接数（使用负值表示没有限制）
    spring.redis.pool.max-active=8
    # 连接池最大阻塞等待时间（使用负值表示没有限制）
    spring.redis.pool.max-wait=-1
    # 连接池中的最大空闲连接
    spring.redis.pool.max-idle=8
    # 连接池中的最小空闲连接
    spring.redis.pool.min-idle=0
    # 连接超时时间（毫秒）
    spring.redis.timeout=0

#### 配置Redis的class文件 ####

package com.frog.mvcdemo.config;
    
    import com.fasterxml.jackson.annotation.JsonAutoDetect;
    import com.fasterxml.jackson.annotation.PropertyAccessor;
    import com.fasterxml.jackson.databind.ObjectMapper;
    import org.springframework.cache.CacheManager;
    import org.springframework.cache.annotation.CacheConfig;
    import org.springframework.cache.annotation.CachingConfigurerSupport;
    import org.springframework.cache.annotation.EnableCaching;
    import org.springframework.cache.interceptor.KeyGenerator;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.data.redis.cache.RedisCacheManager;
    import org.springframework.data.redis.connection.RedisConnectionFactory;
    import org.springframework.data.redis.core.RedisTemplate;
    import org.springframework.data.redis.core.StringRedisTemplate;
    import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
    
    import java.lang.reflect.Method;
    
    @CacheConfig
    @Configuration
    @EnableCaching
    public class RedisConfig extends CachingConfigurerSupport{
    
        @Bean
        public KeyGenerator keyGenerator() {
            return new KeyGenerator() {
                //为给定的方法及其参数生成一个键
                //格式为：com.frog.mvcdemo.controller.FrogTestController-show-[params]
                @Override
                public Object generate(Object target, Method method, Object... params) {
                    StringBuffer sb = new StringBuffer();
                    sb.append(target.getClass().getName());//类名
                    sb.append("-");
                    sb.append(method.getName());//方法名
                    sb.append("-");
                    for (Object param: params ) {
                        sb.append(param.toString());//参数
                    }
                    return sb.toString();
                }
            };
        }
    
        @Bean
        public CacheManager cacheManager(RedisTemplate redisTemplate) {
            RedisCacheManager rcm = new RedisCacheManager(redisTemplate);
            //设置默认的过期时间(以秒为单位)
            rcm.setDefaultExpiration(600);
            //rcm.setExpires();设置缓存区域(按key)的过期时间(以秒为单位)
            return rcm;
        }
    
        @Bean
        public RedisTemplate<String, String> redisTemplate(RedisConnectionFactory factory) {
            StringRedisTemplate template = new StringRedisTemplate(factory);
            Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
            ObjectMapper om = new ObjectMapper();
            om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
            om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
            jackson2JsonRedisSerializer.setObjectMapper(om);
            template.setValueSerializer(jackson2JsonRedisSerializer);
            template.afterPropertiesSet();
            return template;
        }
    }

#### 缓存注解的使用 ####

@Cacheable  
Spring 在执行 @Cacheable 标注的方法前先查看缓存中是否有数据，如果有数据，则直接返回缓存数据；若没有数据，执行该方法并将方法返回值放进缓存。  
参数： value缓存名、 key缓存键值、 condition满足缓存条件、unless否决缓存条件

@CachePut  
和 @Cacheable 类似，但会把方法的返回值放入缓存中, 主要用于数据新增和修改方法

@CacheEvict  
方法执行成功后会从缓存中移除相应数据。  
参数： value缓存名、 key缓存键值、 condition满足缓存条件、 unless否决缓存条件、 allEntries是否移除所有数据（设置为true时会移除所有缓存）

参考链接：  
[http://rensanning.iteye.com/blog/2362184][http_rensanning.iteye.com_blog_2362184]  
[http://blog.csdn.net/whatlookingfor/article/details/51833378][http_blog.csdn.net_whatlookingfor_article_details_51833378]

#### 注解使用 ####

package com.frog.mvcdemo.controller;
    
    import com.frog.mvcdemo.entity.Frog;
    import io.swagger.annotations.ApiImplicitParam;
    import io.swagger.annotations.ApiImplicitParams;
    import io.swagger.annotations.ApiOperation;
    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.web.bind.annotation.*;
    
    import java.util.*;
    
    @CacheConfig(cacheNames = "frogtest")
    @RestController
    @RequestMapping(value = "/frogtest")
    public class FrogTestController {
    
        @Cacheable()
        @ApiOperation(value = "获取Frog的列表")
        @RequestMapping(value = "",method = RequestMethod.GET)
        public List<Frog> show(){
            List<Frog> list = new ArrayList<>();
            list.add(new Frog(1,"one",2,new Date(),"controllertest"));
            list.add(new Frog(2,"two",3,new Date(),"controllertest"));
            return list;
        }
    
        @Cacheable()
        @ApiOperation(value = "获取Frog详细信息",notes = "根据id查询对应Frog信息")
        @ApiImplicitParam(name = "id", value = "ID", required = true, dataType = "int", paramType = "path")
        @RequestMapping(value = "/{id}",method = RequestMethod.GET)
        public Map<String,Object> showById(@PathVariable int id){
            Map<String,Object> map = new HashMap<>();
            if(id == 1){
                map.put("FROG",new Frog(1,"one",3,new Date(),"showById"));
                map.put("RESULT","SUCCESS");
            }else{
                map.put("FROG",null);
                map.put("RESULT","ERROR");
            }
            return map;
        }
    
        @CacheEvict(allEntries = true)
        @ApiOperation(value = "添加Frog详细信息",notes = "添加一条Frog的详细信息")
        @ApiImplicitParam(name = "frog", value = "Frog实体", required = true, dataType = "Frog")
        @RequestMapping(value = "",method = RequestMethod.POST)
        public Map<String,Object> add(@RequestBody Frog frog){
            Map<String,Object> map = new HashMap<>();
            map.put("FROG",frog);
            map.put("RESULT","SUCCESS");
            return map;
        }
    
        @CacheEvict(allEntries = true)
        @ApiOperation(value = "删除Frog详细信息",notes = "根据id删除对应Frog的详细信息")
        @ApiImplicitParam(name = "id", value = "ID", required = true, dataType = "int", paramType = "path")
        @RequestMapping(value = "/{id}",method = RequestMethod.DELETE)
        public Map<String,Object> deleteById(@PathVariable int id){
            Map<String,Object> map = new HashMap<>();
            if(id != 0){
                map.put("FROG",new Frog(id,"testfrog",id,new Date(),"deleteById"));
                map.put("RESULT","SUCCESS");
            }else{
                map.put("FROG",null);
                map.put("RESULT","ERROR");
            }
            return map;
        }
    
        @CacheEvict(allEntries = true)
        @ApiOperation(value = "更新Frog详细信息",notes = "根据id更新Frog的详细信息")
        @ApiImplicitParams({
                @ApiImplicitParam(name = "id", value = "ID", required = true, dataType = "int",paramType = "path"),
                @ApiImplicitParam(name = "frog", value = "Frog实体", required = true, dataType = "Frog")
        })
        @RequestMapping(value = "/{id}",method = RequestMethod.PUT)
        public Map<String,Object> updateById(@PathVariable int id,@RequestBody Frog frog){
            Map<String,Object> map = new HashMap<>();
                map.put("FROG",frog);
                map.put("RESULT","SUCCESS");
                map.put("ID",id);
            return map;
        }
    }

缓存一般加在dao层或service层，发生回滚时保持redis中数据不被清空，这里测试在Controller层加缓存。  
@CacheConfig(cacheNames = “frogtest”)代表这个Controller下需要缓存的方法对应redis中的缓存名为frogtest~keys。  
查询方法都用@Cacheable注解加入缓存  
添加更新删除@CacheEvict(allEntries = true)注解表示执行方法时删除redis中缓存名frogtest~keys下所有缓存

#### redis中keys ####

![这里写图片描述][70]

[http_rensanning.iteye.com_blog_2362184]: http://rensanning.iteye.com/blog/2362184
[http_blog.csdn.net_whatlookingfor_article_details_51833378]: http://blog.csdn.net/whatlookingfor/article/details/51833378
[70]: /images/20220530/d7149132c78943d094a7380fea559f94.png