Springboot--Ehcache-Jpa

Posted 2021-01-12 周无极

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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>{

}

UserRepository

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 + "]";
    }
}

Users

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);
    }

}

UsersServiceImpl

UserService

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);
    }
}

App

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

application.properties

<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>

ehcache.xml

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());
    }
}

UsersServiceTest

<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>

pom.xml

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

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