开启注解缓存_SpringBoot2.x系列教程57SpringBoot中默认缓存实现方案

org.springframework.bootspring-boot-starter-data-jpa
mysqlmysql-connector-java
org.springframework.bootspring-boot-starter-cache


server:port: 8080
spring:application:name: cache-demodatasource:driver-class-name: com.mysql.cj.jdbc.Driverusername: rootpassword: sycurl: jdbc:mysql://localhost:3306/spring-security?useUnicode&＃61;true&characterEncoding&＃61;utf8&characterSetResults&＃61;utf8&useSSL&＃61;false&serverTimezone&＃61;UTC#cache:#type: generic #由redis进行缓存,一共有10种缓存方案jpa:database: mysqlshow-sql: true #开发阶段,打印要执行的sql语句.hibernate:ddl-auto: update

package com.yyg.boot.config;import org.springframework.cache.annotation.EnableCaching;/*** &＃64;Author 一一哥Sun* &＃64;Date Created in 2020/4/14* &＃64;Description Description* EnableCaching启用缓存*/
&＃64;Configuration
&＃64;EnableCaching
public class CacheConfig {
}

package com.yyg.boot.domain;import lombok.Data;
import lombok.ToString;import javax.persistence.*;
import java.io.Serializable;&＃64;Entity
&＃64;Table(name&＃61;"user")
&＃64;Data
&＃64;ToString
public class User implements Serializable {//IllegalArgumentException: DefaultSerializer requires a Serializable payload// but received an object of type [com.syc.redis.domain.User]&＃64;Id&＃64;GeneratedValue(strategy &＃61; GenerationType.AUTO)private Long id;&＃64;Columnprivate String username;&＃64;Columnprivate String password;}

package com.yyg.boot.repository;import com.yyg.boot.domain.User;
import org.springframework.data.jpa.repository.JpaRepository;public interface UserRepository extends JpaRepository {
}

package com.yyg.boot.service;import com.yyg.boot.domain.User;public interface UserService {User findById(Long id);User save(User user);void deleteById(Long id);}

package com.yyg.boot.service.impl;import com.yyg.boot.domain.User;
import com.yyg.boot.repository.UserRepository;
import com.yyg.boot.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.CachePut;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.stereotype.Service;&＃64;Service
public class UserServiceImpl implements UserService {&＃64;Autowiredprivate UserRepository userRepository;//普通的缓存&＃43;数据库查询代码实现逻辑://User user&＃61;RedisUtil.get(key);// if(user&＃61;&＃61;null){// user&＃61;userDao.findById(id);// //redis的key&＃61;"product_item_"&＃43;id// RedisUtil.set(key,user);// }// return user;/*** 注解&＃64;Cacheable:查询的时候才使用该注解!* 注意:在Cacheable注解中支持EL表达式* redis缓存的key&＃61;user_1/2/3....* redis的缓存雪崩,缓存穿透,缓存预热,缓存更新...* condition &＃61; "#result ne null",条件表达式,当满足某个条件的时候才进行缓存* unless &＃61; "#result eq null":当user对象为空的时候,不进行缓存*/&＃64;Cacheable(value &＃61; "user", key &＃61; "#id", unless &＃61; "#result eq null")&＃64;Overridepublic User findById(Long id) {return userRepository.findById(id).orElse(null);}/*** 注解&＃64;CachePut:一般用在添加和修改方法中* 既往数据库中添加一个新的对象,于此同时也往redis缓存中添加一个对应的缓存.* 这样可以达到缓存预热的目的.*/&＃64;CachePut(value &＃61; "user", key &＃61; "#result.id", unless &＃61; "#result eq null")&＃64;Overridepublic User save(User user) {return userRepository.save(user);}/*** CacheEvict:一般用在删除方法中*/&＃64;CacheEvict(value &＃61; "user", key &＃61; "#id")&＃64;Overridepublic void deleteById(Long id) {userRepository.deleteById(id);}}

package com.yyg.boot.web;import com.yyg.boot.domain.User;
import com.yyg.boot.service.UserService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;&＃64;RestController
&＃64;RequestMapping("/user")
&＃64;Slf4j
public class UserController {&＃64;Autowiredprivate UserService userService;&＃64;PostMappingpublic User saveUser(&＃64;RequestBody User user) {return userService.save(user);}&＃64;GetMapping("/{id}")public ResponseEntity getUserById(&＃64;PathVariable("id") Long id) {User user &＃61; userService.findById(id);log.warn("user&＃61;"&＃43;user.hashCode());HttpStatus status &＃61; user &＃61;&＃61; null ? HttpStatus.NOT_FOUND : HttpStatus.OK;return new ResponseEntity<>(user, status);}&＃64;DeleteMapping("/{id}")public String removeUser(&＃64;PathVariable("id") Long id) {userService.deleteById(id);return "ok";}}

package com.yyg.boot;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;&＃64;SpringBootApplication
public class CacheApplication {public static void main(String[] args) {SpringApplication.run(CacheApplication.class, args);}}