转载请注明出处哈:http://carlosfu.iteye.com/blog/2237511

一、依赖

1. ehcache依赖

<ehcache.version>2.6.11</ehcache.version>
<dependency><groupId>net.sf.ehcache</groupId><artifactId>ehcache-core</artifactId><version>${ehcache.version}</version>
</dependency>

2. ehcache依赖树: mvn dependency:tree

[INFO] \- net.sf.ehcache:ehcache-core:jar:2.6.11:compile
[INFO] \- org.slf4j:slf4j-api:jar:1.7.5:compile

3. 由于slf4j-api是日志接口，加入具体实现logback(log4j也可以)

<logback.version>1.0.13</logback.version>
<dependency><groupId>ch.qos.logback</groupId><artifactId>logback-core</artifactId><version>${logback.version}</version>
</dependency>
<dependency><groupId>ch.qos.logback</groupId><artifactId>logback-classic</artifactId><version>${logback.version}</version>
</dependency> 

4. 为了方便单元测试，引入junit

<junit.version>4.11</junit.version>
<dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>${junit.version}</version>
</dependency>

最终pom:

<properties><ehcache.version>2.6.11</ehcache.version><logback.version>1.0.13</logback.version><junit.version>4.11</junit.version></properties><dependencies><dependency><groupId>ch.qos.logback</groupId><artifactId>logback-core</artifactId><version>${logback.version}</version></dependency><dependency><groupId>ch.qos.logback</groupId><artifactId>logback-classic</artifactId><version>${logback.version}</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>${junit.version}</version></dependency><dependency><groupId>net.sf.ehcache</groupId><artifactId>ehcache-core</artifactId><version>${ehcache.version}</version></dependency></dependencies><build><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><version>3.1</version><configuration><source>1.7</source><target>1.7</target><encoding>UTF-8</encoding></configuration></plugin></plugins></build>

二、ehcache配置

注意：如果不添加，会使用ehcache-core-2.6.11.jar下的ehcache-failsafe.xml作为默认配置

一般来说需要把ehcache.xml放到classpath下：我们使用极简配置

<?xml version="1.0" encoding="UTF-8" ?>
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:noNamespaceSchemaLocation="http://ehcache.org/ehcache.xsd"><cache name="firstEhcache" maxElementsInMemory="10000"></cache>
</ehcache>

三、logback配置

<?xml version="1.0" encoding="UTF-8"?>
<configuration scan="true" scanPeriod="5 seconds"><appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"><encoder><pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern></encoder></appender><root level="INFO"><appender-ref ref="STDOUT"/></root>
</configuration>

四、单元测试

1. 一个实体类：

package com.sohu.tv.ehcache.first;
import java.util.Date;
/*** 俱乐部* * @author leifu* @Date 2015年7月28日* @Time 下午1:43:53*/
public class Club {/*** 俱乐部id*/private int id;/*** 俱乐部名*/private String clubName;/*** 俱乐部描述*/private String clubInfo;/*** 创建日期*/private Date createDate;/*** 排名*/private int rank;public Club(int id, String clubName, String clubInfo, Date createDate, int rank) {super();this.id = id;this.clubName = clubName;this.clubInfo = clubInfo;this.createDate = createDate;this.rank = rank;}public Club() {super();}public int getId() {return id;}public void setId(int id) {this.id = id;}public String getClubName() {return clubName;}public void setClubName(String clubName) {this.clubName = clubName;}public String getClubInfo() {return clubInfo;}public void setClubInfo(String clubInfo) {this.clubInfo = clubInfo;}public Date getCreateDate() {return createDate;}public void setCreateDate(Date createDate) {this.createDate = createDate;}public int getRank() {return rank;}public void setRank(int rank) {this.rank = rank;}@Overridepublic String toString() {return "Club [id=" + id + ", clubName=" + clubName + ", clubInfo=" + clubInfo + ", createDate=" + createDate+ ", rank=" + rank + "]";}
}

2. 单元测试：

package com.sohu.tv.ehcache.first;
import java.util.Date;
import org.junit.BeforeClass;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import net.sf.ehcache.Cache;
import net.sf.ehcache.CacheManager;
import net.sf.ehcache.Element;
/*** 第一个ehcache测试* * @author leifu* @Date 2015年8月12日* @Time 上午10:14:13*/
public class FirstEhcacheTest {private static Logger logger = LoggerFactory.getLogger(FirstEhcacheTest.class);private static Cache cache;@BeforeClasspublic static void setUp() {CacheManager cacheManager = CacheManager.create(FirstEhcacheTest.class.getClassLoader().getResourceAsStream("ehcache.xml"));// 打印cacheManager管理的cacheString[] cacheNameArr = cacheManager.getCacheNames();for (String cacheName : cacheNameArr) {logger.info("cacheName: {}", cacheName);}cache = cacheManager.getCache("firstEhcache");}@Testpublic void testCRUD() {logger.info("At start, ehcache object size: {}", cache.getSize());// 唯一keyString key = "football:club:1";Club club = new Club(1, "AC", "AC米兰", new Date(), 1);// 增Element element = new Element(key, club);cache.put(element);logger.info("after add ehcache object size: {}", cache.getSize());// 查Element elementResult = cache.get(key);Club clubResult = (Club) elementResult.getObjectValue();logger.info("get key {} value is {}", key, clubResult.toString());// 修改club.setRank(8888);cache.put(element);logger.info("after set ehcache object size: {}", cache.getSize());// 再查Element elementResultAgain = cache.get(key);Club clubResultAgain = (Club) elementResultAgain.getObjectValue();logger.info("get key {} again value is {}", key, clubResultAgain.toString());// 删boolean removeResult = cache.remove(key);logger.info("remove result is {}, after remove ehcache object size: {}", removeResult, cache.getSize());// 增加一条，观察下次启动cache.put(element);logger.info("At final, ehcache object size: " + cache.getSize());// 生产环境不要使用，影响性能logger.info("At final, ehcache memory size: " + cache.calculateInMemorySize());}
}

五、输出：

10:43:11.405 [main] INFO c.s.t.ehcache.first.FirstEhcacheTest - cacheName: firstEhcache
10:43:11.410 [main] INFO c.s.t.ehcache.first.FirstEhcacheTest - At start, ehcache object size: 0
10:43:11.413 [main] INFO c.s.t.ehcache.first.FirstEhcacheTest - after add ehcache object size: 1
10:43:11.416 [main] INFO c.s.t.ehcache.first.FirstEhcacheTest - get key football:club:1 value is Club [id=1, clubName=AC, clubInfo=AC米兰, createDate=Wed Aug 12 10:43:11 CST 2015, rank=1]
10:43:11.416 [main] INFO c.s.t.ehcache.first.FirstEhcacheTest - after set ehcache object size: 1
10:43:11.417 [main] INFO c.s.t.ehcache.first.FirstEhcacheTest - get key football:club:1 again value is Club [id=1, clubName=AC, clubInfo=AC米兰, createDate=Wed Aug 12 10:43:11 CST 2015, rank=8888]
10:43:11.417 [main] INFO c.s.t.ehcache.first.FirstEhcacheTest - remove result is true, after remove ehcache object size: 0
10:43:11.417 [main] INFO c.s.t.ehcache.first.FirstEhcacheTest - At final, ehcache object size: 1
10:43:11.418 [main] INFO c.s.t.ehcache.first.FirstEhcacheTest - At final, ehcache memory size: 1

六、结论、注意、猜想：

1. 如果没有配置diskStore作为持久化数据源，每次启动时候ehcache都是空的(因为ehcache是进程内缓存，会伴随着JVM的结束而消失)

2. ehcache接口中 put代表了add和set。

3. 官方文档中说：cache.calculateInMemorySize()这个方法不要在生产环境中使用，会影响性能。

4. Ehcache的增删改查API使用十分简单。