本篇文章为大家展示了Spring Boot中怎么集成Ehcache缓存,内容简明扼要并且容易理解,绝对能使你眼前一亮,通过这篇文章的详细介绍希望你能有所收获。
1. 创建一个Spring Boot工程
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:
<?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:
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:
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:
<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:
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
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:
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:
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:
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:
1. 2019-04-07 01:08:01.001 INFO 6704 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 5 ms 2. 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:
1. 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
2. 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。
上述内容就是Spring Boot中怎么集成Ehcache缓存,你们学到知识或技能了吗?如果还想学到更多技能或者丰富自己的知识储备,欢迎关注亿速云行业资讯频道。
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