SpringBoot的缓存技术(整合Ehcache )
废话不多说，直接上项目文件，整体结构如下图所示：
1.修改pom.xml
<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0modelVersion>
<parent>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-parentartifactId>
<version>1.5.10.RELEASEversion>
parent>
<groupId>com.bjsxtgroupId>
<artifactId>23-spring-boot-ehcacheartifactId>
<version>0.0.1-SNAPSHOTversion>
<properties>
<thymeleaf.version>3.0.2.RELEASEthymeleaf.version>
<thymeleaf-layout-dialect.version>2.0.4thymeleaf-layout-dialect.version>
properties>
<dependencies>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-thymeleafartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-data-jpaartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-testartifactId>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
dependency>
<dependency>
<groupId>com.alibabagroupId>
<artifactId>druidartifactId>
<version>1.0.9version>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-cacheartifactId>
dependency>
<dependency>
<groupId>net.sf.ehcachegroupId>
<artifactId>ehcacheartifactId>
dependency>
dependencies>
project>
2.创建Ehcache的配置文件
文件名：ehcache.xml
位置：src/main/resources/ehcache.xml
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="../config/ehcache.xsd">
<diskStore path="java.io.tmpdir" />
<defaultCache
maxElementsInMemory="10000"
eternal="false"
timeToIdleSeconds="120"
timeToLiveSeconds="120"
maxElementsOnDisk="10000000"
diskExpiryThreadIntervalSeconds="120"
memoryStoreEvictionPolicy="LRU">
<persistence strategy="localTempSwap" />
defaultCache>
<cache name="users"
maxElementsInMemory="10000"
eternal="false"
timeToIdleSeconds="120"
timeToLiveSeconds="120"
maxElementsOnDisk="10000000"
diskExpiryThreadIntervalSeconds="120"
memoryStoreEvictionPolicy="LRU">
<persistence strategy="localTempSwap" />
cache>
ehcache>
3.创建application.properties文件（mysql与springDateJpa相关配置）
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/demo01?useSSL=false
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true
spring.cache.ehcache.cofnig=ehcache.xml
这里还是和大家解释一下，MySql在高版本需要指明是否进行SSL连接，这里因为自己的数据库安装的是mysql8.0所以需要加上这个东西，如果用的是mysql5点几版本的朋友可以自行忽略…
什么是SSL
4.启动类
/**
* 启动类
*
* @author admin
*
*/
@SpringBootApplication
@EnableCaching
public class App {
public static void main(String[] args) {
SpringApplication.run(App.class, args);
}
}
5.创建实体类Users
package com.entity;
import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "t_users")
public class Users implements Serializable {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id")
private Integer id;
@Column(name = "name")
private String name;
@Column(name = "age")
private Integer age;
@Column(name = "address")
private String address;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
@Override
public String toString() {
return "Users [id=" + id + ", name=" + name + ", age=" + age + ", address=" + address + "]";
}
public Users(Integer id, String name, Integer age, String address) {
super();
this.id = id;
this.name = name;
this.age = age;
this.address = address;
}
public Users() {
}
}
6.创建service接口，并定义对应得接口方法
package com.service;
import java.util.List;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import com.entity.Users;
public interface UsersService {
List<Users> findUserAll();
Users findUserById(Integer id);
Page<Users> findUserByPage(Pageable pageable);
void saveUsers(Users users);
}
7.接口的实现
package com.service.Impl;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Service;
import com.dao.UsersRepository;
import com.entity.Users;
import com.service.UsersService;
/**
* UsersService接口实现类
*
* @author Administrator
*
*/
@Service
public class UsersServiceImpl implements UsersService {
@Autowired
private UsersRepository usersRepository;
@Override
public List<Users> findUserAll() {
return this.usersRepository.findAll();
}
@Override
// @Cacheable：对当前查询的对象进行缓存处理
// @Cacheable(value = "users")
public Users findUserById(Integer id) {
return this.usersRepository.findOne(id);
}
@Override
public Page<Users> findUserByPage(Pageable pageable) {
return this.usersRepository.findAll(pageable);
}
@Override
public void saveUsers(Users users) {
this.usersRepository.save(users);
}
}
8.定义UsersRepository(来自jpa的神奇力量)
package com.dao;
import org.springframework.data.jpa.repository.JpaRepository;
import com.entity.Users;
/**
* 参数一 T :当前需要映射的实体
* 参数二 ID :当前映射的实体中的OID的类型
*
*/
public interface UsersRepository extends JpaRepository<Users,Integer>{
}
9.开始测试
- 第一次测试
package com.test;
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.test.context.junit4.SpringJUnit4ClassRunner;
import com.App;
import com.entity.Users;
import com.service.UsersService;
/**
* UsersService测试
*
* @author Administrator
*
*/
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = App.class)
public class UsersServiceTest {
@Autowired
private UsersService usersService;
@Test
public void addUser() {
Users users=new Users();
users.setId(1);
users.setAddress("苏站路");
users.setAge(18);
users.setName("张三");
usersService.saveUsers(users);
System.out.println("执行完毕");
}
@Test
public void testFindUserById() {
//第一次查询
System.out.println(this.usersService.findUserById(1));
//第二次查询
System.out.println(this.usersService.findUserById(1));
}
}
测试一结果
-
第二次测试‘’
这里我们将之前在 UserServiceImpl里面的 @Cacheable(value = “users”)取消注释
再次启动项目测试
-
第三次测试
修改UsersServiceImpl里面findUserByPage的方法指定为pageable.pageSize,默认的是pageable
修改测试类
新增方法testFindUserByPage
@Test
public void testFindUserByPage() {
Pageable pageable = new PageRequest(0, 2);
// 第一次查询
System.out.println(this.usersService.findUserByPage(pageable).getTotalElements());
// 第二次查询
System.out.println(this.usersService.findUserByPage(pageable).getTotalElements());
}
测试结果
- 第四次测试(清除缓存：@CacheEvict)
首先在UsersServiceTest中添加测试方法testFindAll，代码如下
@Test
public void testFindAll() {
//第一次查询
System.out.println(this.usersService.findUserAll().size());
//添加用户
Users users = new Users();
users.setId(4);
users.setAddress("苏站路");
users.setAge(18);
users.setName("张三4");
usersService.saveUsers(users);
//第二次查询
System.out.println(this.usersService.findUserAll().size());
}
测试结果一：
由于缓存机制的存在，所以数据库的元素改变了，但是我们用的却还是之前缓存的内容，很显然这不合适。如何解决呢，我们修改UsersServiceImpl,在saveUsers上面填上注解@CacheEvict(value=“users”,allEntries=true)
@Override
//@CacheEvict(value="users",allEntries=true) 清除缓存中以users缓存策略缓存的对象
@CacheEvict(value="users",allEntries=true)
public void saveUsers(Users users) {
this.usersRepository.save(users);
}
再次测试，结果如下：
