jsessionid的解决办法

用户首次登陆系统时，会在地址后面加个jsessionid=xxx导致从外网不能登陆系统，网上搜了一些资料，通过加过滤器的办法解决：

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;
import java.io.IOException;

/**
* Servlet filter which disables URL-encoded session identifiers.
* <p/>
* <pre>
* Copyright (c) 2006, Craig Condit. All rights reserved.
* <p/>
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* <p/>
*    * Redistributions of source code must retain the above copyright notice,
*      this list of conditions and the following disclaimer.
*    * Redistributions in binary form must reproduce the above copyright notice,
*      this list of conditions and the following disclaimer in the documentation
*      and/or other materials provided with the distribution.
* <p/>
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
* </pre>
*/

public class DisableUrlSessionFilter implements Filter {

	/**
	 * Filters requests to disable URL-based session identifiers.
	 */
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		// skip non-http requests
		if (!(request instanceof HttpServletRequest)) {
			chain.doFilter(request, response);
			return;
		}

		HttpServletRequest httpRequest = (HttpServletRequest) request;
		HttpServletResponse httpResponse = (HttpServletResponse) response;

		// clear session if session id in URL
		if (httpRequest.isRequestedSessionIdFromURL()) {
			HttpSession session = httpRequest.getSession();
			if (session != null)
				session.invalidate();
		}

		// wrap response to remove URL encoding
		HttpServletResponseWrapper wrappedResponse = new HttpServletResponseWrapper(
				httpResponse) {
			@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);
	}

	/**
	 * Unused.
	 */
	public void init(FilterConfig config) throws ServletException {
	}

	/**
	 * Unused.
	 */
	public void destroy() {
	}
}

 原文地址：http://randomcoder.com/articles/jsessionid-considered-harmful