Springboot--Ehcache-jpa
package com.bjsxt.dao; import org.springframework.data.jpa.repository.JpaRepository; import com.bjsxt.pojo.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>{ }
package com.bjsxt.pojo; 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 + "]"; } }
package com.bjsxt.service.impl; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.cache.annotation.CacheEvict; 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.bjsxt.dao.UsersRepository; import com.bjsxt.pojo.Users; import com.bjsxt.service.UsersService; /** * UsersService接口实现类 * * */ @Service public class UsersServiceImpl implements UsersService { @Autowired private UsersRepository usersRepository; @Override @Cacheable(value="users") public List<Users> findUserAll() { return this.usersRepository.findAll(); } @Override //@Cacheable:对当前查询的对象做缓存处理 @Cacheable(value="users") public Users findUserById(Integer id) { return this.usersRepository.findOne(id); } @Override @Cacheable(value="users",key="#pageable.pageSize") public Page<Users> findUserByPage(Pageable pageable) { return this.usersRepository.findAll(pageable); } @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); } }
package com.bjsxt; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cache.annotation.EnableCaching; @SpringBootApplication @EnableCaching public class App { public static void main(String[] args) { SpringApplication.run(App.class, args); } }
spring.datasource.driverClassName=com.mysql.jdbc.Driver spring.datasource.url=jdbc:mysql://localhost:3306/orcl spring.datasource.username=root spring.datasource.password=123456 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
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../config/ehcache.xsd"> <diskStore path="java.io.tmpdir"/> <!--defaultCache:echcache的默认缓存策略 --> <defaultCache maxElementsInMemory="10000" eternal="false" timeToIdleSeconds="120" timeToLiveSeconds="120" maxElementsOnDisk="10000000" diskExpiryThreadIntervalSeconds="120" memoryStoreEvictionPolicy="LRU"> <persistence strategy="localTempSwap"/> </defaultCache> <!-- 自定义缓存策略 --> <cache name="users" maxElementsInMemory="10000" eternal="false" timeToIdleSeconds="120" timeToLiveSeconds="120" maxElementsOnDisk="10000000" diskExpiryThreadIntervalSeconds="120" memoryStoreEvictionPolicy="LRU"> <persistence strategy="localTempSwap"/> </cache> </ehcache>
package com.bjsxt.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.data.domain.PageRequest; import org.springframework.data.domain.Pageable; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; import com.bjsxt.App; import com.bjsxt.pojo.Users; import com.bjsxt.service.UsersService; /** * UsersService测试 * * */ @RunWith(SpringJUnit4ClassRunner.class) @SpringBootTest(classes=App.class) public class UsersServiceTest { @Autowired private UsersService usersService; @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)); } @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()); //第三次查询 pageable = new PageRequest(1, 2); System.out.println(this.usersService.findUserByPage(pageable).getTotalElements()); } @Test public void testFindAll(){ //第一次查询 System.out.println(this.usersService.findUserAll().size()); Users users = new Users(); users.setAddress("南京"); users.setAge(43); users.setName("朱七"); this.usersService.saveUsers(users); //第二次查询 System.out.println(this.usersService.findUserAll().size()); } }
<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>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.10.RELEASE</version>
</parent>
<groupId>com.bjsxt</groupId>
<artifactId>23-spring-boot-ehcache</artifactId>
<version>0.0.1-SNAPSHOT</version>
<properties>
<java.version>1.7</java.version>
<thymeleaf.version>3.0.2.RELEASE</thymeleaf.version>
<thymeleaf-layout-dialect.version>2.0.4</thymeleaf-layout-dialect.version>
</properties>
<dependencies>
<!-- springBoot的启动器 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- springBoot的启动器 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<!-- springBoot的启动器 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<!-- 测试工具的启动器 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
</dependency>
<!-- mysql -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<!-- druid连接池 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.0.9</version>
</dependency>
<!-- Spring Boot缓存支持启动器 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<!-- Ehcache坐标 -->
<dependency>
<groupId>net.sf.ehcache</groupId>
<artifactId>ehcache</artifactId>
</dependency>
</dependencies>
</project>
测试一
执行了一条sql ,说明第二次从ehcache里面拿到的,
Hibernate: select users0_.id as id1_0_0_, users0_.address as address2_0_0_, users0_.age as age3_0_0_, users0_.name as name4_0_0_ from t_users users0_ where users0_.id=?
Users [id=1, name=hello, age=34, address=shanghai]
Users [id=1, name=hello, age=34, address=shanghai]
测试二
* 如果是 @Cacheable(value="users",key="#pageable.pageSize")
* 第一次查询 有sql
* 二 没有从缓存取
* 三 没有从缓存取
* @Cacheable(value="users")
* 第一次查询 有sql
* 二 没有从缓存取
* 三 有sql
* 总结就是 ehcahce 缓存是默认把 key 为pageable 存储
* 如果下一次查询和pageable对象相同则 从缓存中取出
测试三
@CacheEvict(value="users",allEntries=true) 清除缓存中以users缓存策略缓存的对象
CacheEvict 用法
当添加数据时,查询数据错误问题,是因为查询的是缓存的数据,并没有查询添加的数据
添加上面注解后,第一次查询和第二次查询都是从数据库里查询的