<span style="font-family:Comic Sans MS;">package com.test.web.common;

import java.io.IOException;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.apache.shiro.SecurityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class NewSessionFilter implements Filter {

	private String url;
	private static final Logger logger = LoggerFactory.getLogger(NewSessionFilter.class);
	public static final String NEW_SESSION_INDICATOR = "com.cacss.sc.web.common.NewSessionFilter";

	public static void newSession(){
		HttpSession session = (HttpSession) SecurityUtils.getSubject().getSession(true);
		session.setAttribute(NEW_SESSION_INDICATOR, true);
	}

	@Override
	public void destroy() {
		System.out.println("NewSessionFilter destory");
	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		System.out.println("NewSessionFilter doFilter");
		
		if (request instanceof HttpServletRequest) {
			HttpServletRequest httpRequest = (HttpServletRequest) request;
			
			//取的url相对地址
	        String url = httpRequest.getRequestURI();  
	        System.out.println(url);  
	        if (httpRequest.getSession() != null) {
	        	System.out.println("NewSessionFilter doFilter httpRequest.getSession().getId()"+ httpRequest.getSession().getId());
				//--------复制 session到临时变量
				HttpSession session = httpRequest.getSession();
				HashMap old = new HashMap();
				Enumeration keys = (Enumeration) session.getAttributeNames();
				
				while (keys.hasMoreElements()){
					String key = (String) keys.nextElement();
					if (!NEW_SESSION_INDICATOR.equals(key)){
						old.put(key, session.getAttribute(key));
						session.removeAttribute(key);
					}
				}
				
				if (httpRequest.getMethod().equals("POST") && httpRequest.getSession() != null 
						&& !httpRequest.getSession().isNew() && httpRequest.getRequestURI().endsWith(url)){
					session.invalidate();
					session=httpRequest.getSession(true);
					logger.debug("new Session:" + session.getId());
				}
				
				//-----------------复制session
				for (Iterator it = old.entrySet().iterator(); it.hasNext();) {
					Map.Entry entry = (Entry) it.next();
					session.setAttribute((String) entry.getKey(), entry.getValue());
				}
			}
		}
		
		chain.doFilter(request, response);
		System.out.println("NewSessionFilter doFilter end");
	}

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
		System.out.println("NewSessionFilter init");
		System.out.println("NewSessionFilter init end");
	}

}</span>

<span style="font-family:Comic Sans MS;"><filter>
	<filter-name>NewSessionFilter</filter-name>
	<filter-class>com.cacss.sc.web.common.NewSessionFilter</filter-class>
</filter>
<filter-mapping>
	<filter-name>NewSessionFilter</filter-name>
	<url-pattern>/login</url-pattern>
</filter-mapping>

</span>

结束语