Spring boot默認使用的是SimpleCacheConfiguration，即使用ConcurrentMapCacheManager來實現緩存。但是要切換到其他緩存實現也很簡單

pom文件

在pom中引入相應的jar包

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

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

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>

    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-dbcp2</artifactId>
    </dependency>
    
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-cache</artifactId>
    </dependency>

    <dependency>
        <groupId>net.sf.ehcache</groupId>
        <artifactId>ehcache</artifactId>
    </dependency>

</dependencies>

配置文件

EhCache所需要的配置文件，只需要放到類路徑下，Spring Boot會自動掃描。

<?xml version="1.0" encoding="UTF-8"?>
<ehcache>
    <cache name="people" maxElementsInMemory="1000"/>
</ehcache>

也可以通過在application.properties文件中，通過配置來指定EhCache配置文件的位置，如：

spring.cache.ehcache.config= #  ehcache配置文件地址

Spring Boot會自動為我們配置EhCacheCacheMannager的Bean。

關鍵Service

package com.xiaolyuh.service.impl;

import com.xiaolyuh.entity.Person;
import com.xiaolyuh.repository.PersonRepository;
import com.xiaolyuh.service.PersonService;
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;

@Service
public class PersonServiceImpl implements PersonService {
    @Autowired
    PersonRepository personRepository;

    @Override
    @CachePut(value = "people", key = "#person.id")
    public Person save(Person person) {
        Person p = personRepository.save(person);
        System.out.println("為id、key為:" + p.getId() + "數據做了緩存");
        return p;
    }

    @Override
    @CacheEvict(value = "people")//2
    public void remove(Long id) {
        System.out.println("刪除了id、key為" + id + "的數據緩存");
        //這里不做實際刪除操作
    }

    @Override
    @Cacheable(value = "people", key = "#person.id")//3
    public Person findOne(Person person) {
        Person p = personRepository.findOne(person.getId());
        System.out.println("為id、key為:" + p.getId() + "數據做了緩存");
        return p;
    }
}

Controller

package com.xiaolyuh.controller;

import com.xiaolyuh.entity.Person;
import com.xiaolyuh.service.PersonService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.CacheManager;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class CacheController {

    @Autowired
    PersonService personService;

    @Autowired
    CacheManager cacheManager;

    @RequestMapping("/put")
    public long put(@RequestBody Person person) {
        Person p = personService.save(person);
        return p.getId();
    }

    @RequestMapping("/able")
    public Person cacheable(Person person) {
        System.out.println(cacheManager.toString());
        return personService.findOne(person);
    }

    @RequestMapping("/evit")
    public String evit(Long id) {

        personService.remove(id);
        return "ok";
    }

}

啟動類

@SpringBootApplication
@EnableCaching// 開啟緩存，需要顯示的指定
public class SpringBootStudentCacheApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringBootStudentCacheApplication.class, args);
    }
}

測試類

package com.xiaolyuh;

import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

import java.util.HashMap;
import java.util.Map;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.http.MediaType;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.MvcResult;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import org.springframework.web.context.WebApplicationContext;

import net.minidev.json.JSONObject;

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringBootStudentCacheApplicationTests {

    @Test
    public void contextLoads() {
    }

    private MockMvc mockMvc; // 模擬MVC對象，通過MockMvcBuilders.webAppContextSetup(this.wac).build()初始化。

    @Autowired
    private WebApplicationContext wac; // 注入WebApplicationContext  

//    @Autowired  
//    private MockHttpSession session;// 注入模擬的http session  
//      
//    @Autowired  
//    private MockHttpServletRequest request;// 注入模擬的http request\  

    @Before // 在測試開始前初始化工作  
    public void setup() {
        this.mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build();
    }

    @Test
    public void testAble() throws Exception {
        for (int i = 0; i < 2; i++) {
            MvcResult result = mockMvc.perform(post("/able").param("id", "2"))
                    .andExpect(status().isOk())// 模擬向testRest發送get請求
                    .andExpect(content().contentType(MediaType.APPLICATION_JSON_UTF8))// 預期返回值的媒體類型text/plain;
                    // charset=UTF-8
                    .andReturn();// 返回執行請求的結果

            System.out.println(result.getResponse().getContentAsString());
        }
    }

}

打印日志

image

從上面可以看出第一次走的是數據庫，第二次走的是緩存

源碼：
https://github.com/wyh-spring-ecosystem-student/spring-boot-student/tree/releases

spring-boot-student-cache-ehcache 工程

為監控而生的多級緩存框架 layering-cache這是我開源的一個多級緩存框架的實現，如果有興趣可以看一下