springboot的缓存技术的实现

这篇文章主要介绍了springboot的缓存技术的实现，小编觉得挺不错的，现在分享给大家，也给大家做个参考。一起跟随小编过来看看吧

引子

我门知道一个程序的瓶颈在于数据库，我门也知道内存的速度是大大快于硬盘的速度的。当我门需要重复的获取相同的数据的时候，我门一次又一次的请求数据库或者远程服务，导致大量的时间耗费在数据库查询或者远程方法的调用上，导致程序性能的恶化，这更是数据缓存要解决的问题。

spring 缓存支持

spring定义了 org.springframework.cache.CacheManager和org.springframework.cache.Cache接口来统一不同的缓存技术。其中，CacheManager是Spring提供的各种缓存技术抽象接口，Cache接口包含了缓存的各种操作（增加、删除获得缓存，我门一般不会直接和此接口打交道）

spring 支持的CacheManager

针对不同的缓存技术，需要实现不同的CacheManager ,spring 定义了如下表的CacheManager实现。

实现任意一种CacheManager 的时候，需要注册实现CacheManager的bean，当然每种缓存技术都有很多额外的配置，但配置CacheManager 是必不可少的。

声明式缓存注解

spring提供了4个注解来声明缓存规则（又是使用注解式的AOP的一个生动例子），如表。

开启声明式缓存

开启声明式缓存支持非常简单，只需要在配置类上使用@EnabelCaching 注解即可。

springBoot 的支持

在spring中国年使用缓存技术的关键是配置CacheManager 而springbok 为我门自动配置了多个CacheManager的实现。在spring boot 环境下，使用缓存技术只需要在项目中导入相关缓存技术的依赖包，并配置类使用@EnabelCaching开启缓存支持即可。

小例子

小例子是使用 springboot+jpa ＋cache 实现的。

实例步骤目录

创建maven项目
数据库配置
jpa配置和cache配置
编写bean 和dao层
编写service层
编写controller
启动cache
测试校验

1.创建maven项目

新建maven 项目pom.xml文件如下内容如下：

   4.0.0com.usspringboot-Cache1.0-SNAPSHOT org.springframework.bootspring-boot-starter-parent1.3.0.RELEASE com.us.Application1.81.8  org.springframework.bootspring-boot-starter-cache org.springframework.bootspring-boot-starter-data-jpa org.springframework.bootspring-boot-starter-web net.sf.ehcacheehcache mysqlmysql-connector-java6.0.5 com.mchangec3p00.9.5.2  commons-loggingcommons-logging

2.数据库配置

在src/main/esouces目录下新建application.properties 文件，内容为数据库连接信息，如下：

application.properties

 ms.db.driverClassName=com.mysql.jdbc.Driver ms.db.url=jdbc:mysql://localhost:3306/cache?prepStmtCacheSize=517&cachePrepStmts=true&autoReconnect=true&useUnicode=true&characterEncoding=utf-8&useSSL=false&allowMultiQueries=true ms.db.username=root ms.db.password=xxxxxx ms.db.maxActive=500

新建DBConfig.java 配置文件，配置数据源

 package com.us.example.config; /** * Created by yangyibo on 17/1/13. */ import java.beans.PropertyVetoException; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.core.env.Environment; import com.mchange.v2.c3p0.ComboPooledDataSource; @Configuration public class DBConfig { @Autowired private Environment env; @Bean(name="dataSource") public ComboPooledDataSource dataSource() throws PropertyVetoException { ComboPooledDataSource dataSource = new ComboPooledDataSource(); dataSource.setDriverClass(env.getProperty("ms.db.driverClassName")); dataSource.setJdbcUrl(env.getProperty("ms.db.url")); dataSource.setUser(env.getProperty("ms.db.username")); dataSource.setPassword(env.getProperty("ms.db.password")); dataSource.setMaxPoolSize(20); dataSource.setMinPoolSize(5); dataSource.setInitialPoolSize(10); dataSource.setMaxIdleTime(300); dataSource.setAcquireIncrement(5); dataSource.setIdleConnectionTestPeriod(60); return dataSource; } }

数据库设计，数据库只有一张Person表，设计如下：

3.jpa配置

spring－data－ jpa 配置文件如下：

 package com.us.example.config; import java.util.HashMap; import java.util.Map; import javax.persistence.EntityManagerFactory; import javax.sql.DataSource; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.ComponentScan; import org.springframework.context.annotation.Configuration; import org.springframework.data.jpa.repository.config.EnableJpaRepositories; import org.springframework.orm.jpa.JpaTransactionManager; import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean; import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter; import org.springframework.transaction.PlatformTransactionManager; import org.springframework.transaction.annotation.EnableTransactionManagement; /** * Created by yangyibo on 17/1/13. */ @Configuration @EnableJpaRepositories("com.us.example.dao") @EnableTransactionManagement @ComponentScan public class JpaConfig { @Autowired private DataSource dataSource; @Bean public EntityManagerFactory entityManagerFactory() { HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter(); LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean(); factory.setJpaVendorAdapter(vendorAdapter); factory.setPackagesToScan("com.us.example.bean"); factory.setDataSource(dataSource); Map jpaProperties = new HashMap<>(); jpaProperties.put("hibernate.ejb.naming_strategy","org.hibernate.cfg.ImprovedNamingStrategy"); jpaProperties.put("hibernate.jdbc.batch_size",50); factory.setJpaPropertyMap(jpaProperties); factory.afterPropertiesSet(); return factory.getObject(); } @Bean public PlatformTransactionManager transactionManager() { JpaTransactionManager txManager = new JpaTransactionManager(); txManager.setEntityManagerFactory(entityManagerFactory()); return txManager; } }

4.编写bean 和dao层

实体类 Person.java

 package com.us.example.bean; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import javax.persistence.Table; /** * Created by yangyibo on 17/1/13. */ @Entity @Table(name = "Person") public class Person { @Id @GeneratedValue private Long id; private String name; private Integer age; private String address; public Person() { super(); } public Person(Long id, String name, Integer age, String address) { super(); this.id = id; this.name = name; this.age = age; this.address = address; } public Long getId() { return id; } public void setId(Long 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; } }

dao层，PersonRepository.java

 package com.us.example.dao; import com.us.example.bean.Person; import org.springframework.data.jpa.repository.JpaRepository; /** * Created by yangyibo on 17/1/13. */ public interface PersonRepository extends JpaRepository { }

5.编写service层

service 接口

 package com.us.example.service; import com.us.example.bean.Person; /** * Created by yangyibo on 17/1/13. */ public interface DemoService { public Person save(Person person); public void remove(Long id); public Person findOne(Person person); }

实现：(重点，此处加缓存)

 package com.us.example.service.Impl; import com.us.example.bean.Person; import com.us.example.dao.PersonRepository; import com.us.example.service.DemoService; 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; /** * Created by yangyibo on 17/1/13. */ @Service public class DemoServiceImpl implements DemoService { @Autowired private PersonRepository personRepository; @Override //@CachePut缓存新增的或更新的数据到缓存,其中缓存名字是 people 。数据的key是person的id @CachePut(value = "people", key = "#person.id") public Person save(Person person) { Person p = personRepository.save(person); System.out.println("为id、key为:"+p.getId()+"数据做了缓存"); return p; } @Override //@CacheEvict 从缓存people中删除key为id 的数据 @CacheEvict(value = "people") public void remove(Long id) { System.out.println("删除了id、key为"+id+"的数据缓存"); //这里不做实际删除操作 } @Override //@Cacheable缓存key为person 的id 数据到缓存people 中,如果没有指定key则方法参数作为key保存到缓存中。 @Cacheable(value = "people", key = "#person.id") public Person findOne(Person person) { Person p = personRepository.findOne(person.getId()); System.out.println("为id、key为:"+p.getId()+"数据做了缓存"); return p; } }

6.编写controller

为了测试方便请求方式都用了get

 package com.us.example.controller; import com.us.example.bean.Person; import com.us.example.service.DemoService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; import org.springframework.web.bind.annotation.RestController; /** * Created by yangyibo on 17/1/13. */ @RestController public class CacheController { @Autowired private DemoService demoService; //http://localhost:8080/put?name=abel&age=23&address=shanghai @RequestMapping("/put") public Person put(Person person){ return demoService.save(person); } //http://localhost:8080/able?id=1 @RequestMapping("/able") @ResponseBody public Person cacheable(Person person){ return demoService.findOne(person); } //http://localhost:8080/evit?id=1 @RequestMapping("/evit") public String evit(Long id){ demoService.remove(id); return "ok"; } }

7.启动cache

启动类中要记得开启缓存配置。

 package com.us.example; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cache.annotation.EnableCaching; import org.springframework.context.ConfigurableApplicationContext; import org.springframework.context.annotation.ComponentScan; import static org.springframework.boot.SpringApplication.*; /** * Created by yangyibo on 17/1/13. */ @ComponentScan(basePackages ="com.us.example") @SpringBootApplication @EnableCaching public class Application { public static void main(String[] args) { ConfigurableApplicationContext run = run(Application.class, args); } }

8.测试校验检验able：

启动Application 类，启动后在浏览器输入：http://localhost:8080/able?id=1（首先要在数据库中初始化几条数据。）