基于方法级别的缓存：通常如果一个带有参数的方法执行后会返回一个Object，那可以认为如果参数相同，则返回的结果一样，这样就可以为这个方法建立一个缓存Map，参数就是KEY，返回的结果就是VALUE，调用此方法前可以先判断参数是否和之前的一样，如果是则从Map中取出结果返回调用者，而无需再进入此方法内执行得到，从而节省了此方法执行时的时间。
http://hanqunfeng.iteye.com/blog/605123经验证，如果要支持分布式的缓存，用spring-modules-cache不好使，必须转用
com.googlecode.ehcache-spring-annotations。
全套MAVEN的POM:
<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>EhCache-Cluster-Tester</groupId>
<artifactId>EhCache-Cluster-Tester</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<dependencies>
<dependency>
<groupId>net.sf.ehcache</groupId>
<artifactId>ehcache-jgroupsreplication</artifactId>
<version>1.4</version>
</dependency>
<!-- Spring framework -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- Spring MVC framework -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.4</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-jdk14</artifactId>
<version>1.5.6</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.13</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>cglib</groupId>
<artifactId>cglib-nodep</artifactId>
<version>2.2.2</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
<!--
<dependency>
<groupId>org.springmodules</groupId>
<artifactId>spring-modules-cache</artifactId>
<version>0.9</version>
<type>jar</type>
<scope>compile</scope>
</dependency>
-->
<dependency>
<groupId>com.googlecode.ehcache-spring-annotations</groupId>
<artifactId>ehcache-spring-annotations</artifactId>
<version>1.2.0</version>
<type>jar</type>
<scope>compile</scope>
<exclusions>
<exclusion>
<artifactId>spring-aop</artifactId>
<groupId>org.springframework</groupId>
</exclusion>
<exclusion>
<artifactId>spring-expression</artifactId>
<groupId>org.springframework</groupId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<build>
<finalName>cluster-test</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.6</source>
<target>1.6</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
<plugin>
<groupId>org.mortbay.jetty</groupId>
<artifactId>jetty-maven-plugin</artifactId>
<version>8.0.4.v20111024</version>
<!--
<artifactId>maven-jetty-plugin</artifactId>
<version>6.1.26</version>
-->
<configuration>
<contextPath>/cluster-test</contextPath>
<scanIntervalSeconds>3</scanIntervalSeconds>
<scanTargetPatterns>
<scanTargetPattern>
<directory>src/main/webapp/WEB-INF</directory>
<excludes>
<exclude>**/*.jsp</exclude>
</excludes>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
</includes>
</scanTargetPattern>
</scanTargetPatterns>
</configuration>
</plugin>
</plugins>
</build>
<properties>
<spring.version>2.5.2</spring.version>
</properties>
</project>