/** 
         * 上传文件 
         */  
        public static String sendFile(String urlPath, String filePath,  
                String newName) throws Exception {  
            String end = "\r\n";  
            String twoHyphens = "--";  
            String boundary = "*****";  
      
            URL url = new URL(urlPath);  
            HttpURLConnection con = (HttpURLConnection) url.openConnection();  
            /* 允许Input、Output，不使用Cache */  
            con.setDoInput(true);  
            con.setDoOutput(true);  
            con.setUseCaches(false);  
            /* 设置传送的method=POST */  
            con.setRequestMethod("POST");  
            /* setRequestProperty */  
      
            con.setRequestProperty("Connection", "Keep-Alive");  
            con.setRequestProperty("Charset", "UTF-8");  
            con.setRequestProperty("Content-Type", "multipart/form-data;boundary="  
                    + boundary);  
            /* 设置DataOutputStream */  
            DataOutputStream ds = new DataOutputStream(con.getOutputStream());  
            ds.writeBytes(twoHyphens + boundary + end);  
            ds.writeBytes("Content-Disposition: form-data; "  
                    + "name=\"file1\";filename=\"" + newName + "\"" + end);  
            ds.writeBytes(end);  
      
            /* 取得文件的FileInputStream */  
            FileInputStream fStream = new FileInputStream(filePath);  
            /* 设置每次写入1024bytes */  
            int bufferSize = 1024;  
            byte[] buffer = new byte[bufferSize];  
      
            int length = -1;  
            /* 从文件读取数据至缓冲区 */  
            while ((length = fStream.read(buffer)) != -1) {  
                /* 将资料写入DataOutputStream中 */  
                ds.write(buffer, 0, length);  
            }  
            ds.writeBytes(end);  
            ds.writeBytes(twoHyphens + boundary + twoHyphens + end);  
      
            /* close streams */  
            fStream.close();  
            ds.flush();  
      
            /* 取得Response内容 */  
            InputStream is = con.getInputStream();  
            int ch;  
            StringBuffer b = new StringBuffer();  
            while ((ch = is.read()) != -1) {  
                b.append((char) ch);  
            }  
            /* 关闭DataOutputStream */  
            ds.close();  
            return b.toString();  
        }

原帖地址：http://blog.csdn.net/lk\_blog/article/details/7706348