http上传下载（2）

package com.upload.http;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.security.Principal;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Locale;
import java.util.Map;
import java.util.Set;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletInputStream;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
public class MultipartRequest implements HttpServletRequest{
    private static final String TEMP_PATH = "c:/temp/";
    private long userId_;
    private HttpServletRequest req_;
    private File dir_ = new File(TEMP_PATH);
private HashMap<String, ArrayList<String>> parameters_ = new HashMap<String, ArrayList<String>>();
    private HashMap<String, UploadedFile> files_ = new HashMap<String, UploadedFile>();
private HashMap<File, String> exactFileNameTable_ = new HashMap<File, String>();
  
    public static boolean isMultipart(HttpServletRequest req) {
        String type = null;
        String type1 = req.getHeader("Content-Type");
        String type2 = req.getContentType();
        if (type1 == null && type2 != null) {
          type = type2;
        }
        else if (type2 == null && type1 != null) {
          type = type1;
        }
        else if (type1 != null && type2 != null) {
          type = (type1.length() > type2.length() ? type1 : type2);
        }
        if (type == null ||!type.toLowerCase().startsWith("multipart/form-data")) {
      return false ;
     }else{
      return true ;
     }
    }
  
public MultipartRequest(HttpServletRequest req, long userId) throws IOException {
        if (req == null)
         throw new IllegalArgumentException("request cannot be null");
        if (!dir_.isDirectory())
         dir_.mkdir();
        if (!dir_.canWrite())
         throw new IllegalArgumentException("服务器上 " + TEMP_PATH + " 这个目录没有写的权限");
        req_ = req;
        userId_ = userId;
        readRequest();
    }

    protected void readRequest()
    throws IOException {
        int length = req_.getContentLength();
        String type = null;
        String type1 = req_.getHeader("Content-Type");
        String type2 = req_.getContentType();
        if (type1 == null && type2 != null) {
            type = type2;
        }
        else if (type2 == null && type1 != null) {
            type = type1;
        }
        else if (type1 != null && type2 != null) {
            type = (type1.length() > type2.length() ? type1 : type2);
        }
        if (type == null ||
            !type.toLowerCase().startsWith("multipart/form-data")) {
            throw new IOException("Posted content type isn't multipart/form-data");
        }
        String boundary = extractBoundary(type);
        if (boundary == null) {
            throw new IOException("Separation boundary was not specified");
        }
        MultipartInputStreamHandler in =
         new MultipartInputStreamHandler(req_.getInputStream(), length);
        String line = in.readLine();
        if (line == null) {
            throw new IOException("Corrupt form data: premature ending");
        }
        if (!line.startsWith(boundary)) {
            throw new IOException("Corrupt form data: no leading boundary");
        }
        boolean done = false;
        while (!done) {
            done = readNextPart(in, boundary);
        }
    }
 
    private String extractBoundary(String line) {
        int index = line.lastIndexOf("boundary=");
        if (index == -1) {
            return null;
        }
        String boundary = line.substring(index + 9);
        boundary = "--" + boundary;
        return boundary;
    }
 
    protected boolean readNextPart(MultipartInputStreamHandler in,
                    String boundary)
    throws IOException {
  String line = in.readLine();
  if (line == null) {
   return true;
  }
  else if (line.length() == 0) {
   return true;
  }
  String[] dispInfo = extractDispositionInfo(line);
  String strHttpParameterName = dispInfo[1];
  String strExactFileName = dispInfo[2];
  line = in.readLine();
  if (line == null) {
   return true;
  }
  String contentType = extractContentType(line);
  if (contentType != null) {
   line = in.readLine();
   if (line == null || line.length() > 0) {
    throw new IOException("Malformed line after content type: " + line);
   }
  }
  else {
   contentType = "application/octet-stream";
  }
  if (strExactFileName == null) {
   String value = readParameter(in, boundary);
   ArrayList<String> existingValues = (ArrayList<String>)parameters_.get(strHttpParameterName);
   if (existingValues == null) {
    existingValues = new ArrayList<String>();
    parameters_.put(strHttpParameterName, existingValues);
   }
   existingValues.add(value);
  }
  else {
   File temporaryFile;
   if (!strExactFileName.equals("unknown")) {
    String tempfilename = userId_ + strHttpParameterName
      + System.currentTimeMillis() + ".bin";
    temporaryFile = new File(dir_, tempfilename);
   } else {
    temporaryFile = null;
   }
 
   readAndSaveFile(in, boundary, temporaryFile, contentType);
 
   if (!strExactFileName.equals("unknown")) {
    files_.put(strHttpParameterName,
       new UploadedFile(temporaryFile, contentType));
   }
   exactFileNameTable_.put(temporaryFile, strExactFileName);
  }
  return false;
    }
  
    protected void readAndSaveFile(MultipartInputStreamHandler in,
            String boundary,
            File temporaryFile,
            String contentType) throws IOException {
  OutputStream out = null;

  if (temporaryFile == null) {
  out = new ByteArrayOutputStream();
  } else {
  if (contentType.equals("application/x-macbinary")){
  out = new MacBinaryDecoderOutputStream(
  new BufferedOutputStream(
   new FileOutputStream(temporaryFile), 8 * 1024));
  }
  else {
  out = new BufferedOutputStream(
     new FileOutputStream(temporaryFile), 8 * 1024);
  }
  }

  byte[] bbuf = new byte[100 * 1024];
  int result;
  String line;
  boolean rnflag = false;
  while ((result = in.readLine(bbuf, 0, bbuf.length)) != -1) {
  if (result > 2 && bbuf[0] == '-' && bbuf[1] == '-') {
  line = new String(bbuf, 0, result, "GB2312");
  if (line.startsWith(boundary)) break;
  }
  if (rnflag) {
  out.write('\r'); out.write('\n');
  rnflag = false;
  }
  if (result >= 2 &&
  bbuf[result - 2] == '\r' &&
  bbuf[result - 1] == '\n') {
  out.write(bbuf, 0, result - 2);
  rnflag = true;
  }
  else {
  out.write(bbuf, 0, result);
  }
  }
  out.close();
}
    private String[] extractDispositionInfo(String line) throws IOException {
        String[] retval = new String[3];
        String origline = line;
        line = origline.toLowerCase();
        int start = line.indexOf("content-disposition: ");
        int end = line.indexOf(";");
        if (start == -1 || end == -1) {
            throw new IOException("Content disposition corrupt: " + origline);
        }
        String disposition = line.substring(start + 21, end);
        if (!disposition.equals("form-data")) {
            throw new IOException("Invalid content disposition: " + disposition);
        }
        start = line.indexOf("name=\"", end);
        end = line.indexOf("\"", start + 7);
        if (start == -1 || end == -1) {
            throw new IOException("Content disposition corrupt: " + origline);
        }
        String name = origline.substring(start + 6, end);
        String filename = null;
        start = line.indexOf("filename=\"", end + 2);
        end = line.indexOf("\"", start + 10);    
        if (start != -1 && end != -1) {       
            filename = origline.substring(start + 10, end);
            int slash =
            Math.max(filename.lastIndexOf('/'), filename.lastIndexOf('\\'));
            if (slash > -1) {
                filename = filename.substring(slash + 1);
            }
            if (filename.equals("")) filename = "unknown";
        }
        retval[0] = disposition;
        retval[1] = name;
        retval[2] = filename;
        return retval;
    }
  
    private String extractContentType(String line) throws IOException {
        String contentType = null;
        String origline = line;
        line = origline.toLowerCase();
        if (line.startsWith("content-type")) {
            int start = line.indexOf(" ");
            if (start == -1) {
                throw new IOException("Content type corrupt: " + origline);
            }
            contentType = line.substring(start + 1);
        }
        else if (line.length() != 0) {
            throw new IOException("Malformed line after disposition: " + origline);
        }
        return contentType;
    }

protected String readParameter(MultipartInputStreamHandler in,
            String boundary) throws IOException {
  StringBuffer sbuf = new StringBuffer();
  String line;
  while ((line = in.readLine()) != null) {
  if (line.startsWith(boundary)) break;
  sbuf.append(line + "\r\n");
  }
  if (sbuf.length() == 0) {
  return "";
  }
  sbuf.setLength(sbuf.length() - 2);
  return sbuf.toString();
    }
  
    public File getFile(String strParameterName) {
  UploadedFile file = (UploadedFile)files_.get(strParameterName);
  if (file != null) {
   return file.getFile();
  } else {
   return null;
  }
}