HTTP SESSION的管理通常是由容器來做，但如果是在PAAS環境下，服務器不能做變更，則需要由WEB應用來做處理HTTP SESSION。
同樣，如果是分布式的環境下，SESSION的管理也會帶來性能問題。
SPRING推出了處理SESSION的框架：SPRING-SESSION。
SPRING會重寫HTTP SESSION的那一套，使用SESSION也同樣還是用
req.getSession().setAttribute(attributeName, attributeValue);
此框架使用REDIS作為HTTP SESSION的持久化容器。此框架只對使用的當前WEB應用下的HTTP SESSION進行集中管理，同一WEB容器下的其他WEB應用還是會使用容器的SESSION管理那一套。
pom.xml
<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>com.paul</groupId>
<artifactId>spring-session</artifactId>
<packaging>war</packaging>
<version>1.0</version>
<repositories>
<repository>
<id>spring-snapshot</id>
<url>https://repo.spring.io/libs-milestone</url>
</repository>
<repository>
<id>clojars.org</id>
<url>http://clojars.org/repo</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>org.springframework.session</groupId>
<artifactId>spring-session</artifactId>
<version>1.0.0.RC1</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-redis</artifactId>
<version>1.3.0.RELEASE</version>
</dependency>
<dependency>
<groupId>redis.clients</groupId>
<artifactId>jedis</artifactId>
<version>2.4.1</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-pool2</artifactId>
<version>2.2</version>
</dependency>
<dependency>
<groupId>redis.embedded</groupId>
<artifactId>embedded-redis</artifactId>
<version>0.3</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.tomcat.maven</groupId>
<artifactId>tomcat7-maven-plugin</artifactId>
<version>2.0</version>
<configuration>
<path>/</path>
</configuration>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
</plugins>
</build>
<properties>
<spring.version>4.1.0.RELEASE</spring.version>
</properties>
</project>
在ECLIPSE中運行TOMCAT的文件：spring-session-tomcat-run.launch
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<launchConfiguration type="org.eclipse.m2e.Maven2LaunchConfigurationType">
<booleanAttribute key="M2_DEBUG_OUTPUT" value="false"/>
<stringAttribute key="M2_GOALS" value="tomcat7:run"/>
<booleanAttribute key="M2_NON_RECURSIVE" value="false"/>
<booleanAttribute key="M2_OFFLINE" value="false"/>
<stringAttribute key="M2_PROFILES" value=""/>
<listAttribute key="M2_PROPERTIES"/>
<stringAttribute key="M2_RUNTIME" value="EMBEDDED"/>
<booleanAttribute key="M2_SKIP_TESTS" value="false"/>
<intAttribute key="M2_THREADS" value="1"/>
<booleanAttribute key="M2_UPDATE_SNAPSHOTS" value="false"/>
<booleanAttribute key="M2_WORKSPACE_RESOLUTION" value="false"/>
<stringAttribute key="org.eclipse.jdt.launching.VM_ARGUMENTS" value="-Dspring.profiles.active=dev"/>
<stringAttribute key="org.eclipse.jdt.launching.WORKING_DIRECTORY" value="${workspace_loc:/spring-session}"/>
</launchConfiguration>
啟動內置REDIS服務器的文件：EmbeddedRedisConfiguration.java
package com.paul.springsesseion;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import redis.clients.jedis.Protocol;
import redis.embedded.RedisServer;
/**
* Runs an embedded Redis instance. This is only necessary since we do not want
* users to have to setup a Redis instance. In a production environment, this
* would not be used since a Redis Server would be setup.
*
* @author Rob Winch
*/
@Configuration
public class EmbeddedRedisConfiguration {
@Bean
public RedisServerBean redisServer() {
return new RedisServerBean();
}
class RedisServerBean implements InitializingBean, DisposableBean {
private RedisServer redisServer;
@Override
public void afterPropertiesSet() throws Exception {
redisServer = new RedisServer(Protocol.DEFAULT_PORT);
redisServer.start();
}
@Override
public void destroy() throws Exception {
if(redisServer != null) {
redisServer.stop();
}
}
}
}
配置文件：Config.java
package com.paul.springsesseion;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
import org.springframework.session.data.redis.config.annotation.web.http.EnableRedisHttpSession;
/**
* @author Rob Winch
*/
@Import(EmbeddedRedisConfiguration.class)
@Configuration
@EnableRedisHttpSession
public class Config {
@Bean
public JedisConnectionFactory connectionFactory() {
return new JedisConnectionFactory();
}
}
初始化配置文件：Initializer.java
package com.paul.springsesseion;
import org.springframework.session.web.context.AbstractHttpSessionApplicationInitializer;
/**
* @author Rob Winch
*/
public class Initializer extends AbstractHttpSessionApplicationInitializer {
public Initializer() {
super(Config.class);
}
}
存取HTTP SESSION：SessionServlet.java
package com.paul.springsesseion;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
/**
* @author Rob Winch
*/
@WebServlet("/session")
public class SessionServlet extends HttpServlet {
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
String attributeName = req.getParameter("attributeName");
String attributeValue = req.getParameter("attributeValue");
req.getSession().setAttribute(attributeName, attributeValue);
resp.sendRedirect(req.getContextPath() + "/");
}
private static final long serialVersionUID = 2878267318695777395L;
}
頁面：index.jsp
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html lang="en">
<head>
<title>Session Attributes</title>
<link rel="stylesheet" href="assets/bootstrap.min.css">
<style type="text/css">
body {
padding: 1em;
}
</style>
</head>
<body>
<div class="container">
<h1>Description</h1>
<p>This application demonstrates how to use a Redis instance to back your session. Notice that there is no JSESSIONID cookie. We are also able to customize the way of identifying what the requested session id is.</p>
<h1>Try it</h1>
<form class="form-inline" role="form" action="./session" method="post">
<label for="attributeValue">Attribute Name</label>
<input id="attributeValue" type="text" name="attributeName"/>
<label for="attributeValue">Attribute Value</label>
<input id="attributeValue" type="text" name="attributeValue"/>
<input type="submit" value="Set Attribute"/>
</form>
<hr/>
<table class="table table-striped">
<thead>
<tr>
<th>Attribute Name</th>
<th>Attribute Value</th>
</tr>
</thead>
<tbody>
<c:forEach items="${sessionScope}" var="attr">
<tr>
<td><c:out value="${attr.key}"/></td>
<td><c:out value="${attr.value}"/></td>
</tr>
</c:forEach>
</tbody>
</table>
</div>
</body>
</html>
參考：
https://github.com/spring-projects/spring-session