Memcached在SpringMVC上的使用

1、memcached介绍

　　memcached是一款由Danga Interactive公司开发的高效的分布式缓存服务器，主要是用于解决数据量庞大、访问集中的Web应用出现的数据库服务器负担过重，数据库相应延迟导致的网站显示延迟的情况，通过它可以缓存数据库访问结果，减少应用直接访问数据库的次数，提高系统相应速度。

2、在SpringMVC项目中使用memcached

1）准备工作

下载安装memcached服务器，安装过程Linux参考http://www.runoob.com/memcached/memcached-install.html，Window参考http://www.runoob.com/memcached/window-install-memcached.html

2）创建SpringMVC项目

3）添加maven依赖

<?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>groupId</groupId>
    <artifactId>spring-memcached</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties>
        <java-version>1.8</java-version>
        <spring-version>4.1.5.RELEASE</spring-version>
        <log4j-version>2.8</log4j-version>
    </properties>

    <repositories>
        <repository>
            <id>aliyun</id>
            <name>aliyun</name>
            <url>http://maven.aliyun.com/nexus/content/groups/public</url>
        </repository>
    </repositories>

    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring-version}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${spring-version}</version>
        </dependency>

        <!-- json -->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.8.1</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.8.1</version>
        </dependency>
        <dependency>
            <groupId>org.codehaus.jackson</groupId>
            <artifactId>jackson-core-asl</artifactId>
            <version>1.9.12</version>
        </dependency>
        <dependency>
            <groupId>org.codehaus.jackson</groupId>
            <artifactId>jackson-mapper-asl</artifactId>
            <version>1.9.12</version>
        </dependency>
        <!-- end json -->

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.35</version>
        </dependency>

        <dependency>
            <groupId>com.googlecode.xmemcached</groupId>
            <artifactId>xmemcached</artifactId>
            <version>2.2.0</version>
        </dependency>

    </dependencies>

    <build>
        <finalName>spring-memcached</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.5</version>
                <configuration>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

4）applicationContext.xml配置

memcached.properties

memcached.connectionPoolSize=10
memcached.failureMode=true

#server1
server1.memcached.host:127.0.0.1
server1.memcached.port:11211
server1.memcached.weight=4

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"
       default-autowire="byName">
    <description>Spring公共配置</description>
    <context:annotation-config/>

    <context:component-scan base-package="com.weidai.memcached">
        <!-- 在装载spring mvc 时会加载这些Controller 因此在这边排除加载 如果不排除会造成事务失效 -->
        <context:exclude-filter expression="org.springframework.stereotype.Controller" type="annotation" />
    </context:component-scan>

    <!-- 载入类路径下的properties属性文件 -->
    <context:property-placeholder location="classpath*:config/*.properties" />
    <bean id="memcachedClientBuilder" class="net.rubyeye.xmemcached.XMemcachedClientBuilder"
          p:connectionPoolSize="${memcached.connectionPoolSize}" p:failureMode="${memcached.failureMode}"

    >
        <constructor-arg>
            <list>
                <bean class="java.net.InetSocketAddress">
                    <constructor-arg>
                        <value>${server1.memcached.host}</value>
                    </constructor-arg>
                    <constructor-arg>
                        <value>${server1.memcached.port}</value>
                    </constructor-arg>
                </bean>
            </list>
        </constructor-arg>
        <constructor-arg>
            <list>
                <value>${server1.memcached.weight}</value>
            </list>
        </constructor-arg>
        <property name="commandFactory">
            <bean class="net.rubyeye.xmemcached.command.TextCommandFactory" />
        </property>
        <property name="sessionLocator">
            <bean class="net.rubyeye.xmemcached.impl.KetamaMemcachedSessionLocator" />
        </property>

        <property name="transcoder">
            <bean class="net.rubyeye.xmemcached.transcoders.SerializingTranscoder" />
        </property>
    </bean>

    <bean id="memcachedClient" factory-bean="memcachedClientBuilder" factory-method="build" destroy-method="shutdown">

    </bean>
</beans>

5）memcached客户端API选择xmemcached示例如下

package com.weidai.memcached.cache;

import net.rubyeye.xmemcached.MemcachedClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component
public abstract class MemcachedBasis<T> {
    @Autowired
    protected MemcachedClient memcachedClient;
    /** 数据失效时间 **/
    protected int EXPIRE_TIME = 3600*24;
    /** 基础数据失效时间 **/
    protected int DATA_EXPIRE_TIME = this.EXPIRE_TIME*7;

    protected  static final String PREFIX = "SPRINGMEMCACHEDDEMO";

    protected static final String SEPERATOR = "_";

    protected   abstract  String getDataId();
    public  abstract  String generateKey(String type, String ... params);

    public Boolean set(String key, T model){
        Boolean result = Boolean.FALSE;
        try {
            result = memcachedClient.set(key, this.EXPIRE_TIME, model);
        }catch(Exception ex){
        }
        return result;
    }

    public<T> T get(String key){
        T model = null;
        try {
            model = memcachedClient.get(key);
        }catch(Exception ex){
        }
        return model;
    }

}