Java 在我们将重定向到的url中注入标头

Java 在我们将重定向到的url中注入标头,java,jsp,Java,Jsp,我想在url中插入标题并重定向,我已经尝试了下面的链接,但它不起作用。请帮助我如何在java中执行此操作 package com.bitplan.smartCRM.web; 导入java.io.IOException; 导入java.util.Collections; 导入java.util.Enumeration; 导入java.util.HashMap; 导入java.util.List; 导入java.util.Map; 导入javax.servlet.Filter; 导入javax.s

我想在url中插入标题并重定向,我已经尝试了下面的链接,但它不起作用。请帮助我如何在java中执行此操作

package com.bitplan.smartCRM.web;
导入java.io.IOException;
导入java.util.Collections;
导入java.util.Enumeration;
导入java.util.HashMap;
导入java.util.List;
导入java.util.Map;
导入javax.servlet.Filter;
导入javax.servlet.FilterChain;
导入javax.servlet.FilterConfig;
导入javax.servlet.ServletException;
导入javax.servlet.ServletRequest;
导入javax.servlet.ServletResponse;
导入javax.servlet.http.HttpServletRequest;
导入javax.servlet.http.HttpServletRequestWrapper;
/**
* 
*@author wf
* 
*/
公共类RemoteAddrFilter实现筛选器{
@凌驾
公共空间销毁(){
}
@凌驾
public void doFilter(ServletRequest请求、ServletResponse响应、,
FilterChain链)抛出IOException、ServletException{
HttpServletRequest req=(HttpServletRequest)请求;
HeaderPrequestWrapper requestWrapper=新的HeaderPrequestWrapper(请求);
字符串remote_addr=request.getRemoteAddr();
addHeader(“remote\u addr”,remote\u addr);
doFilter(requestWrapper,response);//转到默认servlet。
}
@凌驾
public void init(FilterConfig FilterConfig)抛出ServletException{
}
// https://stackoverflow.com/questions/2811769/adding-an-http-header-to-the-request-in-a-servlet-filter
// http://sandeepmore.com/blog/2010/06/12/modifying-http-headers-using-java/
// http://bijubnair.blogspot.de/2008/12/adding-header-information-to-existing.html
/**
*允许向请求添加其他标头条目
* 
*@author wf
* 
*/
公共类HeaderPrequestWrapper扩展了HttpServletRequestWrapper{
/**
*为此请求构造一个包装器
* 
*@param请求
*/
公共headerPrequestWrapper(HttpServletRequest请求){
超级(请求);
}
private Map headerMap=new HashMap();
/**
*添加具有给定名称和值的标题
* 
*@param name
*@param值
*/
public void addHeader(字符串名称、字符串值){
headerMap.put(名称、值);
}
@凌驾
公共字符串getHeader(字符串名称){
字符串headerValue=super.getHeader(名称);
if(总部地址:containsKey(姓名)){
headerValue=headerMap.get(名称);
}
返回headerValue;
}
/**
*获取标题名称
*/
@凌驾
公共枚举getHeaderNames(){
列表名称=Collections.List(super.getHeaderNames());
for(字符串名称:headerMap.keySet()){
名称。添加(名称);
}
返回集合。枚举(名称);
}
@凌驾
公共枚举getHeaders(字符串名称){
列表值=Collections.List(super.getHeaders(name));
if(总部地址:containsKey(姓名)){
add(headerMap.get(name));
}
返回集合。枚举(值);
}
}
}
remoteAddrfilter
com.bitplan.smartCRM.web.RemoteAddrFilter
remoteAddrfilter
/*

能否添加您尝试的代码段以及您遇到的问题/错误?我是否理解正确,您希望获取当前请求,添加/修改一些标题,重定向到另一个页面,然后将这些标题包含在新请求中?这实际上是不可能的(至少在没有繁重编码的情况下,无论是服务器端还是浏览器端),浏览器都会发送一个新的请求,因此修改后的标题会丢失。无论如何,我可以想象一些变通方法(例如使用会话)。
  package com.bitplan.smartCRM.web;

 import java.io.IOException;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

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.HttpServletRequestWrapper;

 /**
 * 
 * @author wf
 * 
 */
public class RemoteAddrFilter implements Filter {

@Override
public void destroy() {

}

@Override
public void doFilter(ServletRequest request, ServletResponse response,
        FilterChain chain) throws IOException, ServletException {
    HttpServletRequest req = (HttpServletRequest) request;
    HeaderMapRequestWrapper requestWrapper = new HeaderMapRequestWrapper(req);
    String remote_addr = request.getRemoteAddr();
    requestWrapper.addHeader("remote_addr", remote_addr);
    chain.doFilter(requestWrapper, response); // Goes to default servlet.
}

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

}

// https://stackoverflow.com/questions/2811769/adding-an-http-header-to-the-request-in-a-servlet-filter
// http://sandeepmore.com/blog/2010/06/12/modifying-http-headers-using-java/
// http://bijubnair.blogspot.de/2008/12/adding-header-information-to-existing.html
/**
 * allow adding additional header entries to a request
 * 
 * @author wf
 * 
 */
public class HeaderMapRequestWrapper extends HttpServletRequestWrapper {
    /**
     * construct a wrapper for this request
     * 
     * @param request
     */
    public HeaderMapRequestWrapper(HttpServletRequest request) {
        super(request);
    }

    private Map<String, String> headerMap = new HashMap<String, String>();

    /**
     * add a header with given name and value
     * 
     * @param name
     * @param value
     */
    public void addHeader(String name, String value) {
        headerMap.put(name, value);
    }

    @Override
    public String getHeader(String name) {
        String headerValue = super.getHeader(name);
        if (headerMap.containsKey(name)) {
            headerValue = headerMap.get(name);
        }
        return headerValue;
    }

    /**
     * get the Header names
     */
    @Override
    public Enumeration<String> getHeaderNames() {
        List<String> names = Collections.list(super.getHeaderNames());
        for (String name : headerMap.keySet()) {
            names.add(name);
        }
        return Collections.enumeration(names);
    }

    @Override
    public Enumeration<String> getHeaders(String name) {
        List<String> values = Collections.list(super.getHeaders(name));
        if (headerMap.containsKey(name)) {
            values.add(headerMap.get(name));
        }
        return Collections.enumeration(values);
    }

}

}


  <!--  first filter adds remote addr header -->
  <filter>
  <filter-name>remoteAddrfilter</filter-name>
  <filter-class>com.bitplan.smartCRM.web.RemoteAddrFilter</filter-class>
 </filter>
 <filter-mapping>
  <filter-name>remoteAddrfilter</filter-name>
 <url-pattern>/*</url-pattern>
 </filter-mapping>