javax.servlet.http.HttpServletRequestWrapper進行包裝

package com.pica.cloud.foundation.utils.utils;

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedReader;
import 
 
java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.util.*;

/**
 * @param
* @author liugen.wen sixvision
 * @version V1.0    1、request克隆  2、提供增加header裡面放置物件的方法
 * @ClassName:
* @Description:
* @date 2018/6/26 14:03
 */
public class 
 
BodyReaderHttpServletRequestWrapper extends HttpServletRequestWrapper {

    private final byte[] body;

    private Map<String,String> headerMap;

    public BodyReaderHttpServletRequestWrapper(HttpServletRequest request) throws IOException {
        super(request);
        // 提取原本的HEADER內容
Enumeration enumeration = request.getHeaderNames();
        headerMap 
 
= new HashMap<String,String>();
        while(enumeration.hasMoreElements()) {
            String name = (String) enumeration.nextElement();
            headerMap.put(name, request.getHeader(name));
        }

        body = HttpHelper.getBodyString(request).getBytes(Charset.forName("UTF-8"));
    }

    @Override
public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(getInputStream()));
    }

    @Override
public ServletInputStream getInputStream() throws IOException {

        final ByteArrayInputStream bais = new ByteArrayInputStream(body);

        return new ServletInputStream() {

            @Override
public int read() throws IOException {
                return bais.read();
            }

            @Override
public boolean isFinished() {
                return false;
            }

            @Override
public boolean isReady() {
                return false;
            }

            @Override
public void setReadListener(ReadListener readListener) {

            }
        };
    }


    public void addHeader(String name,String value) {
        headerMap.put(name, value);
    }


    @Override
public String getHeader(String name) {
        return headerMap.get(name);
    }

    @Override
public Enumeration getHeaderNames() {
        Set<String> set = new HashSet<String>(headerMap.keySet());
        Enumeration<String> e = ((HttpServletRequest) getRequest()).getHeaderNames();
        while (e.hasMoreElements()) {
            String n = e.nextElement();
            set.add(n);
        }
        // create an enumeration from the set and return
return Collections.enumeration(set);
    }

    public Map getHeaderMap() {
        return headerMap;
    }

    public void setHeaderMap(Map headerMap) {
        this.headerMap = headerMap;
    }
}

在使用的時候（建議在Filter中）  就先new   再直接 addHeader   再把物件傳遞下去

BodyReaderHttpServletRequestWrapper requestWrapper = new BodyReaderHttpServletRequestWrapper(req);

requestWrapper.addHeader("picaUser", URLEncoder.encode(JSONObject.toJSONString(picaUser), "UTF-8"));

chain.doFilter(requestWrapper, resp);