一、springboot缓存简介

在 Spring Boot中，通过@EnableCaching注解自动化配置合适的缓存管理器（CacheManager），Spring Boot根据下面的顺序去侦测缓存提供者：

* Generic

* JCache (JSR-107)

* EhCache 2.x

* Hazelcast

* Infinispan

* Redis

* Guava

* Simple

关于 Spring Boot 的缓存机制：

高速缓存抽象不提供实际存储，并且依赖于由org.springframework.cache.Cache和org.springframework.cache.CacheManager接口实现的抽象。 Spring Boot根据实现自动配置合适的CacheManager，只要缓存支持通过@EnableCaching注释启用即可。

二、实例

1、application.properyies

server.port=8850#cache 多个用逗号分开spring.cache.cache-names=userCachespring.cache.jcache.config=classpath:ehcache.xml# datasourcespring.datasource.name=ehcahcetestspring.datasource.driver-class-name=com.mysql.jdbc.Driverspring.datasource.url=jdbc:mysql://127.0.0.1:3312/ehcahcetestspring.datasource.username=rootspring.datasource.password=123456# mybatismybatis.mapper-locations=classpath:mybatis/mapper/*.xmlmybatis.config-location=classpath:mybatis/mybatis-config.xml#mybatis.type-aliases-package=

2、springboot启动类

1 @SpringBootApplication2 @ComponentScan(basePackages="com.ehcache")//扫描组件3 @EnableCaching4 public class EhcacheTestApplication {5 6     public static void main(String[] args) {7         SpringApplication.run(EhcacheTestApplication.class, args);8     }9 }

3、加了缓存注解的service

1 @Service 2 public class UserService { 3      4     @Autowired 5     private UserDao userDao; 6  7     @CacheEvict(key="'user_'+#uid", value="userCache") 8     public void del(String uid) { 9         // TODO Auto-generated method stub10         userDao.del(uid);11     }12 13     @CachePut(key="'user_'+#user.uid", value="userCache")14     public void update(User user) {15         userDao.update(user);16     }17     18     @Cacheable(key="'user_'+#uid",value="userCache")19     public User getUserById(String uid){20         System.err.println("缓存里没有"+uid+",所以这边没有走缓存，从数据库拿数据");21         return userDao.findById(uid);22         23     }24 25     @CacheEvict(key="'user'",value="userCache")26     public String save(User user) {27         // TODO Auto-generated method stub28         return userDao.save(user);29     }30 31     32 }

 4、ehcache.xml

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       34         35         36         
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       47                     48                     49          
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       53 54     
      55 56 
     

5、OperationController.java 测试类

1 package com.ehcache.controller;  2   3 import java.util.ArrayList;  4 import java.util.HashMap;  5 import java.util.List;  6 import java.util.Map;  7   8 import javax.servlet.http.HttpServletRequest;  9  10 import org.springframework.beans.factory.annotation.Autowired; 11 import org.springframework.cache.annotation.CachePut; 12 import org.springframework.cache.annotation.Cacheable; 13 import org.springframework.web.bind.annotation.RequestMapping; 14 import org.springframework.web.bind.annotation.RequestMethod; 15 import org.springframework.web.bind.annotation.RequestParam; 16 import org.springframework.web.bind.annotation.ResponseBody; 17 import org.springframework.web.bind.annotation.RestController; 18  19 import com.ehcache.entity.User; 20 import com.ehcache.factory.CacheManagerFactory; 21 import com.ehcache.factory.UserFactory; 22 import com.ehcache.service.UserService; 23 import com.google.gson.Gson; 24  25 import net.sf.ehcache.Element; 26  27  28 @RestController 29 @RequestMapping("/o") 30 public class OperationController { 31      32     @Autowired 33     private UserService userService; 34      35     Gson gson = new Gson(); 36      37     CacheManagerFactory cmf = CacheManagerFactory.getInstance(); 38      39     @RequestMapping(value = "/test", method = RequestMethod.GET) 40     public String test(HttpServletRequest request){ 41          42         // 保存一个新用户 43         String uid = userService.save(UserFactory.createUser()); 44         User user = userService.getUserById(uid); 45         user.setUsername("xiaoli"); 46         userService.update(user); 47          48         // 查询该用户 49         System.out.println(gson.toJson(user, User.class)); 50         /*System.out.println(); 51         // 再查询该用户 52         User user = userService.getUserById(uid); 53         System.out.println(gson.toJson(user, User.class)); 54         System.out.println(); 55         // 更新该用户 56         userService.update(user); 57         // 更新好了再查询该用户 58         System.out.println(gson.toJson(userService.getUserById(uid), User.class)); 59         System.out.println(); 60         // 删除该用户 61         userService.del(uid); 62         System.out.println(); 63         // 删除好了再查询该用户 64         System.out.println(gson.toJson(userService.getUserById(uid), User.class));*/ 65          66          67         // 再保存一个新用户 68 //        String uid1 = userService.save(UserFactory.createUser()); 69          70          71         return uid; 72     } 73      74      75     @RequestMapping(value = "/test1", method = RequestMethod.GET) 76     public String test1(HttpServletRequest request,String key){ 77          78         String res = ""; 79  80         Element element = cmf.getElement("userCache", "map"); 81         if(element == null){ 82             Map
     
       map = new HashMap
      
       (); 83             map.put(key, key); 84             cmf.setElement("userCache", new Element("map", map)); 85         }else{ 86             Map
       
         map = (Map
        
         ) element.getValue(); 87             res = map.get(key); 88             if(res == null){ 89                 map.put(key, key); 90                 // 多次测试发现，存在同名Element是，重复put的是无法复制的，因此当遇到两个节点同步不上的时候，先remove后put。  91                 cmf.getCache("userCache").remove("map"); 92                 cmf.setElement("userCache", new Element("map", map)); 93                 res = "0;null"; 94             } 95         } 96         return res; 97     } 98      99     100 }