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springboot的缓存技术的实现

程序员文章站 2023-12-18 21:48:34
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...

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。

springboot的缓存技术的实现

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。

springboot的缓存技术的实现

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

  1. 创建maven项目
  2. 数据库配置
  3. jpa配置和cache配置
  4. 编写bean 和dao层
  5. 编写service层
  6. 编写controller
  7. 启动cache
  8. 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:

<?xml version="1.0" encoding="utf-8"?>
<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>

 <groupid>com.us</groupid>
 <artifactid>springboot-cache</artifactid>
 <version>1.0-snapshot</version>
 <parent>
  <groupid>org.springframework.boot</groupid>
  <artifactid>spring-boot-starter-parent</artifactid>
  <version>1.3.0.release</version>
 </parent>

 <properties>
  <start-class>com.us.application</start-class>

  <maven.compiler.target>1.8</maven.compiler.target>
  <maven.compiler.source>1.8</maven.compiler.source>
 </properties>

 <!-- add typical dependencies for a web application -->
 <dependencies>
  <dependency>
   <groupid>org.springframework.boot</groupid>
   <artifactid>spring-boot-starter-cache</artifactid>
  </dependency>
  <dependency>
   <groupid>org.springframework.boot</groupid>
   <artifactid>spring-boot-starter-data-jpa</artifactid>
  </dependency>
  <dependency>
   <groupid>org.springframework.boot</groupid>
   <artifactid>spring-boot-starter-web</artifactid>
  </dependency>

  <dependency>
   <groupid>net.sf.ehcache</groupid>
   <artifactid>ehcache</artifactid>
  </dependency>

  <!--db-->

  <dependency>
   <groupid>mysql</groupid>
   <artifactid>mysql-connector-java</artifactid>
   <version>6.0.5</version>
  </dependency>
  <dependency>
   <groupid>com.mchange</groupid>
   <artifactid>c3p0</artifactid>
   <version>0.9.5.2</version>
   <exclusions>
    <exclusion>
     <groupid>commons-logging</groupid>
     <artifactid>commons-logging</artifactid>
    </exclusion>
   </exclusions>
  </dependency>

 </dependencies>

</project>

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:

springboot的缓存技术的实现

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<string, object> 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<person, long> {

}

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。)

springboot的缓存技术的实现

控制台输出:

“为id、key为:1数据做了缓存“ 此时已经为此次查询做了缓存,再次查询该条数据将不会出现此条语句,也就是不查询数据库了。

检验put

在浏览器输入:http://localhost:8080/put?name=abel&age=23&address=shanghai(向数据库插入一条数据,并将数据放入缓存。)

springboot的缓存技术的实现

此时控制台输出为该条记录做了缓存:

springboot的缓存技术的实现

然后再次调用able 方法,查询该条数据,将不再查询数据库,直接从缓存中读取数据。

测试evit

在浏览器输入:http://localhost:8080/evit?id=1(将该条记录从缓存中清楚,清除后,在次访问该条记录,将会重新将该记录放入缓存。)

控制台输出:

springboot的缓存技术的实现

切换缓存

1.切换为ehcache作为缓存

pom.xml 文件中添加依赖

<dependency>
   <groupid>net.sf.ehcache</groupid>
   <artifactid>ehcache</artifactid>
  </dependency>

在resource 文件夹下新建ehcache的配置文件ehcache.xml 内容如下,此文件spring boot 会自动扫描

<?xml version="1.0" encoding="utf-8"?>
<ehcache>
 <!--切换为ehcache 缓存时使用-->
<cache name="people" maxelementsinmemory="1000" />
</ehcache>

2.切换为guava作为缓存

只需要在pom中添加依赖

 <dependency>
   <groupid>com.google.guava</groupid>
   <artifactid>guava</artifactid>
   <version>18.0</version>
  </dependency>

3.切换为redis作为缓存

请看下篇博客

本文参考:《javaee开发的颠覆者:spring boot实战 》

本文源代码:https://github.com/527515025/springboot.git

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。

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