一个过滤器不仅解决了会话标识未更新同时还顺带解决了已解密的登录请求

package com.filter;
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.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
*
* 会话标识未更新
* */
public class NewSessionFilter extends HttpServlet implements Filter {
/**
*
*/
private static final long serialVersionUID = 831349987977760012L;
static ServletRequest request;
private String url;
private static final Logger logger = LoggerFactory.getLogger(NewSessionFilter.class);
public static final String NEW_SESSION_INDICATOR = "com.filter.NewSessionFilter";

static HttpServletRequest request2 = (HttpServletRequest) request;
public static void newSession(){
HttpSession session = request2.getSession(true);
session.setAttribute(NEW_SESSION_INDICATOR, true);
}

@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 destroy() {
// System.out.println("NewSessionFilter destory");
}

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

}

<!--配置过滤器 会话标识未更新 过滤  -->

<filter>
<filter-name>NewSessionFilter</filter-name>
<filter-class>com.filter.NewSessionFilter</filter-class>
</filter>
<!--映射过滤器-->
<filter-mapping>
<filter-name>NewSessionFilter</filter-name>
<!--“/*”表示拦截所有的请求 -->
<url-pattern>/*</url-pattern>
</filter-mapping>