模拟form表单上传图片

转自：http://blog.csdn.net/5iasp/article/details/8669644#comments 

public static void main(String[] args) {
  
  String filepath="d:\\test\\1.jpg";  
  String urlStr = "http://localhost:8080/minicms/picup.jsp";  
  Map<String, String> txtMap = new HashMap<String, String>(); 
  txtMap.put("name", "testname");

  Map<String, String> fMap = new HashMap<String, String>();  
  fMap.put("userfile", filepath);  
  String ret = formUpload(urlStr, txtMap, fMap);  
  System.out.println(ret);
  }
 
 public static String formUploadTest(String urlStr, Map<String, String> textMap,Map<String, String> fileMap) {
  String res = null;
  HttpURLConnection conn = null;
  String BOUNDARY = "***********************"; //注：request头和上传文件内容的分隔符
  try {
   URL url = new URL(urlStr);
   conn = (HttpURLConnection) url.openConnection();
   conn.setConnectTimeout(5000);
   conn.setReadTimeout(30000);
   conn.setDoOutput(true);
   conn.setDoInput(true);
   conn.setUseCaches(false);
   conn.setRequestMethod("POST");
   conn.setRequestProperty("Connection", "Keep-Alive");
   conn.setRequestProperty("User-Agent","Mozilla/5.0 (Windows; U; Windows NT 6.1; zh-CN; rv:1.9.2.6)");
   conn.setRequestProperty("Content-Type","multipart/form-data; boundary=" + BOUNDARY);

   OutputStream out = new DataOutputStream(conn.getOutputStream());
   // 一、
   if (textMap != null && textMap.size>0) {
    StringBuffer strBuf = new StringBuffer();
    Iterator iter = textMap.entrySet().iterator();
    while (iter.hasNext()) {
     Map.Entry entry = (Map.Entry) iter.next();
     String inputName = (String) entry.getKey();
     String inputValue = (String) entry.getValue();
     if (inputValue == null) {
      continue;
     }
     strBuf.append("\r\n").append("--").append(BOUNDARY).append("\r\n");
     strBuf.append("Content-Disposition: form-data; name=\"" + inputName + "\"\r\n\r\n");
     strBuf.append(inputValue);
    }
    out.write(strBuf.toString().getBytes());
   }

   // 图片
   if (fileMap != null && textMap.size>0) {
    Iterator iter = fileMap.entrySet().iterator();
    while (iter.hasNext()) {
     Map.Entry entry = (Map.Entry) iter.next();
     String inputName = (String) entry.getKey();
     String inputValue = (String) entry.getValue();
     if (inputValue == null) 
      continue;

     File file = new File(inputValue);
     String filename = file.getName();
     String contentType = new MimetypesFileTypeMap().getContentType(file);
     if (filename!=null && filename.endsWith(".png")) 
      contentType = "image/png";
    
     if (contentType == null || contentType.equals("")) 
      contentType = "application/octet-stream";

     StringBuffer strBuf = new StringBuffer();
     strBuf.append("\r\n").append("--").append(BOUNDARY).append( "\r\n");
     strBuf.append("Content-Disposition: form-data; name=\""
       + inputName + "\"; filename=\"" + filename  + "\"\r\n");
     strBuf.append("Content-Type:" + contentType + "\r\n\r\n");

     out.write(strBuf.toString().getBytes());

     DataInputStream in = new DataInputStream(new FileInputStream(file));
     int bytes = 0;
     byte[] bufferOut = new byte[1024];
     while ((bytes = in.read(bufferOut)) != -1) 
      out.write(bufferOut, 0, bytes);

     in.close();
    }
   }

   byte[] endData = ("\r\n--" + BOUNDARY + "--\r\n").getBytes();
   out.write(endData);
   out.flush();
   out.close();

   //测试是否上传成功
   StringBuffer strBuf = new StringBuffer();
   BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
   String line = null;
   while ((line = reader.readLine()) != null) 
    strBuf.append(line).append("\n");
   
   res = strBuf.toString();
   reader.close();
   reader = null;
  } catch (Exception e) {
   System.out.println("发送POST请求出错。" + urlStr);
   e.printStackTrace();
  } finally {
   if (conn != null) {
    conn.disconnect();
    conn = null;
   }
  }
  return res;
 }

}