去除URL中带有的jsessionid

url中有Jsessionid生成的原因：
jsessionid是标明session的id的（有点废话。。。），它是存在于cookie中的，一般情况下不会出现在url中，服务器会从客户端的cookie中取出来，但是如果客户端禁用了cookie的话，就要重写url了，显式的将jsessionid重写到Url中，方便服务器来通过这个找到session的id。

如果客户端请求的cookie中不包含JSESSIONID，服务端调用request.getSession()时就会生成并传递给客户端，此次响应头会包含设置cookie的信息

如果客户端请求的cookie中包含JSESSIONID，服务端调用request.getSession()时就会根据JSESSIONID进行查找对象，如果能查到就返回，否则就跟没传递JSESSIONID一样；

解决方式1.在客户端页面上，判断Url是否包含Jsessionid，有的就移除

方式2.后台编写一个过滤器，判断如果请求url中带有sessionid，则进行处理

import java.io.IOException;

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.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;
import javax.servlet.http.HttpSession;

public class RemoveUrlJsessionIdFilter implements Filter{


    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        HttpServletResponse httpServletResponse = (HttpServletResponse) response;
        // skip non-http requests
        if (!(request instanceof HttpServletRequest)) {
             chain.doFilter(request, response);
            return;
         }

        //从url中删除jsessionid
        // isRequestedSessionIdFromURL():Checks whether the requested session ID came in as part of the request URL.
        if (httpServletRequest.isRequestedSessionIdFromURL()) {
            HttpSession session = httpServletRequest.getSession();
            if (null != session) {
                session.invalidate();
            }
        }
         // wrap response to remove URL encoding
          HttpServletResponseWrapper wrappedResponse = new HttpServletResponseWrapper(httpServletResponse) {
           @Override
           public String encodeRedirectUrl(String url) {
            return url;
           }
           @Override
           public String encodeRedirectURL(String url) {
            return url;
           }
           @Override
           public String encodeUrl(String url) {
            return url;
           }
           @Override
           public String encodeURL(String url) {
            return url;
           }
          };
          // process next request in chain
          chain.doFilter(request, wrappedResponse);
    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }



    @Override
    public void destroy() {

    }

}

web.xml

    <filter>
        <filter-name>RemoveUrlJsessionIdFilterfilter-name>
        <filter-class>spring.filter.RemoveUrlJsessionIdFilterfilter-class>
        <async-supported>trueasync-supported>
    filter>
    <filter-mapping>
        <filter-name>RemoveUrlJsessionIdFilterfilter-name>
        <url-pattern>/*url-pattern>
    filter-mapping>