本次内容主要介绍基于ehcache 3.0来快速实现spring boot应用程序的数据缓存功能。在spring boot应用程序中,我们可以通过spring caching来快速搞定数据缓存。接下来我们将介绍如何在三步之内搞定spring boot缓存。
1. 创建一个spring boot工程并添加maven依赖
你所创建的spring boot应用程序的maven依赖文件至少应该是下面的样子:
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<?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> <parent> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-parent</artifactid> <version> 2.1 . 3 .release</version> <relativepath/> <!-- lookup parent from repository --> </parent> <groupid>com.ramostear</groupid> <artifactid>cache</artifactid> <version> 0.0 . 1 -snapshot</version> <name>cache</name> <description>demo project for spring boot</description> <properties> <java.version> 1.8 </java.version> </properties> <dependencies> <dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-cache</artifactid> </dependency> <dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-web</artifactid> </dependency> <dependency> <groupid>org.ehcache</groupid> <artifactid>ehcache</artifactid> </dependency> <dependency> <groupid>javax.cache</groupid> <artifactid>cache-api</artifactid> </dependency> <dependency> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-starter-test</artifactid> <scope>test</scope> </dependency> <dependency> <groupid>org.projectlombok</groupid> <artifactid>lombok</artifactid> </dependency> </dependencies> <build> <plugins> <plugin> <groupid>org.springframework.boot</groupid> <artifactid>spring-boot-maven-plugin</artifactid> </plugin> </plugins> </build> </project> |
依赖说明:
- spring-boot-starter-cache为spring boot应用程序提供缓存支持
- ehcache提供了ehcache的缓存实现
- cache-api 提供了基于jsr-107的缓存规范
2. 配置ehcache缓存
现在,需要告诉spring boot去哪里找缓存配置文件,这需要在spring boot配置文件中进行设置:
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spring.cache.jcache.config=classpath:ehcache.xml |
然后使用@enablecaching注解开启spring boot应用程序缓存功能,你可以在应用主类中进行操作:
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package com.ramostear.cache; import org.springframework.boot.springapplication; import org.springframework.boot.autoconfigure.springbootapplication; import org.springframework.cache.annotation.enablecaching; @springbootapplication @enablecaching public class cacheapplication { public static void main(string[] args) { springapplication.run(cacheapplication. class , args); } } |
接下来,需要创建一个ehcache的配置文件,该文件放置在类路径下,如resources目录下:
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<config xmlns:xsi= "http://www.w3.org/2001/xmlschema-instance" xmlns= "http://www.ehcache.org/v3" xmlns:jsr107= "http://www.ehcache.org/v3/jsr107" xsi:schemalocation=" http: //www.ehcache.org/v3 http://www.ehcache.org/schema/ehcache-core-3.0.xsd http: //www.ehcache.org/v3/jsr107 http://www.ehcache.org/schema/ehcache-107-ext-3.0.xsd"> <service> <jsr107:defaults enable-statistics= "true" /> </service> <cache alias= "person" > <key-type>java.lang. long </key-type> <value-type>com.ramostear.cache.entity.person</value-type> <expiry> <ttl unit= "minutes" > 1 </ttl> </expiry> <listeners> <listener> < class >com.ramostear.cache.config.personcacheeventlogger</ class > <event-firing-mode>asynchronous</event-firing-mode> <event-ordering-mode>unordered</event-ordering-mode> <events-to-fire-on>created</events-to-fire-on> <events-to-fire-on>updated</events-to-fire-on> <events-to-fire-on>expired</events-to-fire-on> <events-to-fire-on>removed</events-to-fire-on> <events-to-fire-on>evicted</events-to-fire-on> </listener> </listeners> <resources> <heap unit= "entries" > 2000 </heap> <offheap unit= "mb" > 100 </offheap> </resources> </cache> </config> |
最后,还需要定义个缓存事件监听器,用于记录系统操作缓存数据的情况,最快的方法是实现cacheeventlistener接口:
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package com.ramostear.cache.config; import org.ehcache.event.cacheevent; import org.ehcache.event.cacheeventlistener; import org.slf4j.logger; import org.slf4j.loggerfactory; /** * @author ramostear * @create-time 2019/4/7 0007-0:48 * @modify by : * @since: */ public class personcacheeventlogger implements cacheeventlistener<object,object>{ private static final logger logger = loggerfactory.getlogger(personcacheeventlogger. class ); @override public void onevent(cacheevent cacheevent) { logger.info( "person caching event {} {} {} {}" , cacheevent.gettype(), cacheevent.getkey(), cacheevent.getoldvalue(), cacheevent.getnewvalue()); } } |
3. 使用@cacheable注解对方法进行注释
要让spring boot能够缓存我们的数据,还需要使用@cacheable注解对业务方法进行注释,告诉spring boot该方法中产生的数据需要加入到缓存中:
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package com.ramostear.cache.service; import com.ramostear.cache.entity.person; import org.springframework.cache.annotation.cacheable; import org.springframework.stereotype.service; /** * @author ramostear * @create-time 2019/4/7 0007-0:51 * @modify by : * @since: */ @service (value = "personservice" ) public class personservice { @cacheable (cachenames = "person" ,key = "#id" ) public person getperson( long id){ person person = new person(id, "ramostear" , "ramostear@163.com" ); return person; } } |
通过以上三个步骤,我们就完成了spring boot的缓存功能。接下来,我们将测试一下缓存的实际情况。
4. 缓存测试
为了测试我们的应用程序,创建一个简单的restful端点,它将调用personservice返回一个person对象:
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package com.ramostear.cache.controller; import com.ramostear.cache.entity.person; import com.ramostear.cache.service.personservice; import org.springframework.beans.factory.annotation.autowired; import org.springframework.http.httpstatus; import org.springframework.http.responseentity; import org.springframework.web.bind.annotation.getmapping; import org.springframework.web.bind.annotation.pathvariable; import org.springframework.web.bind.annotation.requestmapping; import org.springframework.web.bind.annotation.restcontroller; /** * @author ramostear * @create-time 2019/4/7 0007-0:54 * @modify by : * @since: */ @restcontroller @requestmapping ( "/persons" ) public class personcontroller { @autowired private personservice personservice; @getmapping ( "/{id}" ) public responseentity<person> person( @pathvariable (value = "id" ) long id){ return new responseentity<>(personservice.getperson(id), httpstatus.ok); } } |
person是一个简单的pojo类:
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package com.ramostear.cache.entity; import lombok.allargsconstructor; import lombok.getter; import lombok.noargsconstructor; import lombok.setter; import java.io.serializable; /** * @author ramostear * @create-time 2019/4/7 0007-0:45 * @modify by : * @since: */ @getter @setter @allargsconstructor @noargsconstructor public class person implements serializable{ private long id; private string username; private string email; } |
以上准备工作都完成后,让我们编译并运行应用程序。项目成功启动后,使用浏览器打开: http://localhost:8080/persons/1 ,你将在浏览器页面中看到如下的信息:
{"id":1,"username":"ramostear","email":"ramostear@163.com"}
此时在观察控制台输出的日志信息:
2019-04-07 01:08:01.001 info 6704 --- [nio-8080-exec-1] o.s.web.servlet.dispatcherservlet : completed initialization in 5 ms
2019-04-07 01:08:01.054 info 6704 --- [e [_default_]-0] c.r.cache.config.personcacheeventlogger : person caching event created 1 null com.ramostear.cache.entity.person@ba8a729
由于我们是第一次请求api,没有任何缓存数据。因此,ehcache创建了一条缓存数据,可以通过 created 看一了解到。
我们在ehcache.xml文件中将缓存过期时间设置成了1分钟(1),因此在一分钟之内我们刷新浏览器,不会看到有新的日志输出,一分钟之后,缓存过期,我们再次刷新浏览器,将看到如下的日志输出:
2019-04-07 01:09:28.612 info 6704 --- [e [_default_]-1] c.r.cache.config.personcacheeventlogger : person caching event expired 1 com.ramostear.cache.entity.person@a9f3c57 null
2019-04-07 01:09:28.612 info 6704 --- [e [_default_]-1] c.r.cache.config.personcacheeventlogger : person caching event created 1 null com.ramostear.cache.entity.person@416900ce
第一条日志提示缓存已经过期,第二条日志提示ehcache重新创建了一条缓存数据。
结束语
在本次案例中,通过简单的三个步骤,讲解了基于ehcache的spring boot应用程序缓存实现。文章内容重在缓存实现的基本步骤与方法,简化了具体的业务代码,有兴趣的朋友可以自行扩展,期间遇到问题也可以随时与我联系。
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服务器之家。
原文链接:https://juejin.im/post/5ca8e8516fb9a05e3b24c01b