http session的管理通常是由容器来做，但如果是在paas环境下，服务器不能做变更，则需要由web应用来做处理http session。
同样，如果是分布式的环境下，session的管理也会带来性能问题。
spring推出了处理session的框架：spring-session。
spring会重写http session的那一套，使用session也同样还是用
req.getsession().setattribute(attributename, attributevalue);
此框架使用redis作为http session的持久化容器。此框架只对使用的当前web应用下的http session进行集中管理，同一web容器下的其他web应用还是会使用容器的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>4.0.0modelversion>
<groupid>com.paulgroupid>
<artifactid>spring-sessionartifactid>
<packaging>warpackaging>
<version>1.0version>
<repositories>
<repository>
<id>spring-snapshotid>
<url>https://repo.spring.io/libs-milestoneurl>
repository>
<repository>
<id>clojars.orgid>
<url>http://clojars.org/repourl>
repository>
repositories>
<dependencies>
<dependency>
<groupid>org.springframework.sessiongroupid>
<artifactid>spring-sessionartifactid>
<version>1.0.0.rc1version>
dependency>
<dependency>
<groupid>org.springframeworkgroupid>
<artifactid>spring-webartifactid>
<version>${spring.version}version>
dependency>
<dependency>
<groupid>org.springframework.datagroupid>
<artifactid>spring-data-redisartifactid>
<version>1.3.0.releaseversion>
dependency>
<dependency>
<groupid>redis.clientsgroupid>
<artifactid>jedisartifactid>
<version>2.4.1version>
dependency>
<dependency>
<groupid>org.apache.commonsgroupid>
<artifactid>commons-pool2artifactid>
<version>2.2version>
dependency>
<dependency>
<groupid>redis.embeddedgroupid>
<artifactid>embedded-redisartifactid>
<version>0.3version>
dependency>
<dependency>
<groupid>javax.servletgroupid>
<artifactid>javax.servlet-apiartifactid>
<version>3.1.0version>
<scope>providedscope>
dependency>
<dependency>
<groupid>jstlgroupid>
<artifactid>jstlartifactid>
<version>1.2version>
dependency>
dependencies>
<build>
<plugins>
<plugin>
<groupid>org.apache.tomcat.mavengroupid>
<artifactid>tomcat7-maven-pluginartifactid>
<version>2.0version>
<configuration>
<path>/path>
configuration>
plugin>
<plugin>
<artifactid>maven-compiler-pluginartifactid>
<version>3.1version>
<configuration>
<source>1.7source>
<target>1.7target>
configuration>
plugin>
plugins>
build>
<properties>
<spring.version>4.1.0.releasespring.version>
properties>
project>
在eclipse中运行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>
启动内置redis服务器的文件：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;
}
页面：index.jsp
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
doctype html>
<html lang="en">
<head>
<title>session attributestitle>
<link rel="stylesheet" href="assets/bootstrap.min.css">
<style type="text/css">
body {
padding: 1em;
}
style>
head>
<body>
<div class="container">
<h1>descriptionh1>
<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 ith1>
<form class="form-inline" role="form" action="./session" method="post">
<label for="attributevalue">attribute namelabel>
<input id="attributevalue" type="text" name="attributename"/>
<label for="attributevalue">attribute valuelabel>
<input id="attributevalue" type="text" name="attributevalue"/>
<input type="submit" value="set attribute"/>
form>
<hr/>
<table class="table table-striped">
<thead>
<tr>
<th>attribute nameth>
<th>attribute valueth>
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>
参考：