对 request 重新封装，使得 request 可以从此从 InputStream 中取值。和 HttpHelper.java 一起使用。

WrappedRequest.java

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.util.Enumeration;

import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;


/**
 * 用于将request重新进行封装
 *
 *
 */
public class WrappedRequest extends HttpServletRequestWrapper
{
    private final byte[] body;

    public WrappedRequest(HttpServletRequest request)
        throws IOException
    {
        super(request);
        body = HttpHelper.getBodyString(request).getBytes(Charset.forName("UTF-8"));
    }

    public WrappedRequest(HttpServletRequest request, JSONObject extraParam)
        throws IOException
    {
        super(request);
        JSONObject json = JSON.parseObject(HttpHelper.getBodyString(request));
        json.putAll(extraParam);
        body = json.toJSONString().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 String getHeader(String name)
    {
        return super.getHeader(name);
    }

    @Override
    public Enumeration<String> getHeaderNames()
    {
        return super.getHeaderNames();
    }

    @Override
    public Enumeration<String> getHeaders(String name)
    {
        return super.getHeaders(name);
    }
}