如何更改java Servlet过滤器中的传入URL并将请求重定向到新URL

Question

我创建了一个webapp，我正在修改url中的参数来解密其中一个参数。解密后，我想将参数附加到新的URL，以便我可以获得预期的响应。我创建了一个收集输入的HTML，登陆页面是我正在拦截请求的Java页面。我不希望请求转到目标网页，而是希望将其发送到新网址。

下面是我的过滤器代码。

    package com.test.secondServlet;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

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.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

/**
 * Servlet Filter implementation class SecondFilter
 */
@WebFilter("/SecondFilter")
public class SecondFilter implements Filter {
    public String decryptedString;
    private static final String characterEncoding = "UTF-8";
    Properties prop = new Properties();
    InputStream input = null;
    public String globalKey;
    public String RedirectURL;
    public String DN;
    public String TYPE;
    public String NAME;
    public String NUMBER;
    /**
     * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
     */

     @Override
        public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
         //chain.doFilter(req, res);    
         HttpServletRequest request = (HttpServletRequest) req;
            //String requestURI = request.getRequestURI();
            //System.out.println(requestURI);
            String url = ((HttpServletRequest)request).getRequestURL().toString() +"?"+request.getQueryString();
            System.out.println(url);
            String queryString = ((HttpServletRequest)request).getQueryString();
            DN = ((HttpServletRequest) request).getParameter("DN");
            TYPE = ((HttpServletRequest) request).getParameter("TYPE");
            NAME = ((HttpServletRequest) request).getParameter("NAME");
            NUMBER = ((HttpServletRequest) request).getParameter("encryptedssn");
           // String key = ((HttpServletRequest) request).getParameter("aeskey");   

          //Code to load key from property file
            try {

                String filename = "Secretkey.properties";
                input = SecondFilter.class.getClassLoader().getResourceAsStream(filename);
                if(input==null){
                        System.out.println("Sorry, unable to find " + filename);
                    return;
                }

                //load a properties file from class path, inside static method
                prop.load(input);
                //get the property value and print it out
                globalKey=prop.getProperty("Secretkey");
                System.out.println("Global Key : "+globalKey);

            } catch (IOException ex) {
                ex.printStackTrace();
            } 
            //code ends 

            if (queryString!=null) {

                //decryptingssnhere
                    byte[] clearText;
                    try {
                        clearText = AesEncryption.decryptBase64EncodedWithManagedIV(NUMBER, globalKey);
                        decryptedString = new String(clearText,characterEncoding);
                        System.out.println("ClearText:" +decryptedString);
                    } catch (Exception e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    // System.out.println("ClearText:" + new String(clearText,characterEncoding));

            //if(url.startsWith("/SSNdecrypt/SSNdecrypt")){
            System.out.println("queryString :"+queryString);
            System.out.println("DN : "+DN);
            System.out.println("TYPE : "+TYPE);
            System.out.println("NAME : "+NAME);
            System.out.println("S1/ NUMBER : "+NUMBER);
            //System.out.println("key : "+key);
            System.out.println("decrypted S1/ Number : "+decryptedString);
            //String toReplace = url.substring(38);
            System.out.println("input : "+input);
            //String Redirect = "SSNdecrypt?"+queryString.substring(0,13)+decryptedString;
            //System.out.println("redirect : "+Redirect);
            //String newURI = url.replace(queryString, Redirect);
            //System.out.println("new URL"+newURI);
            //String newURI = url.concat("?"+newquerystring);

            RedirectURL = "http://differentservername.com/contentexplorer/servlet/VipDms?";
            String Redirect =RedirectURL+"DN="+DN+"&TYPE="+TYPE+"&NAME="+NAME+"&-NUMBER="+decryptedString;          
            System.out.println("redircting new URL for DOCVIEW : "+Redirect);

            final HttpServletRequestWrapper wrapped = new HttpServletRequestWrapper(request) {
                @Override
                public StringBuffer getRequestURL() {
                    final StringBuffer originalUrl = ((HttpServletRequest) getRequest()).getRequestURL();
                    return new StringBuffer(Redirect);
                }
            };
            //chain.doFilter(wrapped, res);
            wrapped.getRequestDispatcher(Redirect).forward(wrapped, res);

            } else {
                chain.doFilter(req, res);
            }
            //SSNdecrypt/SSNdecrypt?encryptedssn=1234
            //res.getWriter().println(requestURI.toString());

        /**if (request instanceof HttpServletRequest) {
             String url = ((HttpServletRequest)request).getRequestURL().toString();
             String queryString = ((HttpServletRequest)request).getQueryString();
            }**/
    }

    /**
     * @see Filter#init(FilterConfig)
     */
    public void init(FilterConfig fConfig) throws ServletException {
        // TODO Auto-generated method stub
    }
    /**
     * @see Filter#destroy()
     */
    public void destroy() {
        // TODO Auto-generated method stub
    }
     }

我不想使用urlrewriter并希望在同一个过滤器中执行此操作。如何更改请求的URL？

Answer 1

我正在使用HttpServletResponse resp = (HttpServletResponse) res; resp.sendRedirect(Redirect);而不是转发wrapped.getRequestDispatcher(Redirect).forward(wrapped, res);的请求。我使用HTTP响应包装器而不是使用请求qrapper，而是能够从请求URL修改完整的URL。