J2ee 断点续传 及 post请求中 包含 url参数及文件流

首先

client端：

HttpURLConnection conn = null;BufferedInputStream fin = null;BufferedOutputStream out = null;URL reqUrl;try {reqUrl = new URL("http://<ip>:<port>/Emergency/phone/attachmentUpload");conn = (HttpURLConnection) reqUrl.openConnection();conn.setConnectTimeout(3000);conn.setRequestMethod("PUT");if(isCommit){conn.setRequestProperty("isCommit", "true");}else{conn.setRequestProperty("isCommit", "false");}conn.setRequestMethod("PUT");conn.setRequestProperty("Content-Type", "binary/octet-stream");conn.setRequestProperty("offset", StringUtil.toString(offset));conn.setDoOutput(true);conn.setDoInput(true);// 1M的chunk缓冲conn.setChunkedStreamingMode(1024*1024);out = new BufferedOutputStream(conn.getOutputStream());fin = new BufferedInputStream(new FileInputStream(file));byte[] buf = new byte[bufferSizeUpload];int len = -1;long currentUploadSize = offset;fin.skip(offset);while ((len = fin.read(buf)) != -1&currentUploadSize<offset+uploadSize) {if(offset+uploadSize-currentUploadSize<bufferSizeUpload){len = Integer.parseInt(StringUtil.toString(offset+uploadSize-currentUploadSize));}if(len>0){if(out!=null){out.write(buf, 0, len);out.flush();}}currentUploadSize += len;}} catch (SocketTimeoutException e) {e.printStackTrace();} catch(IOException e){e.printStackTrace();} finally {try {if (fin != null) {fin.close();fin = null;}if (out != null) {out.close();out = null;}if (conn != null) {conn.disconnect();conn = null;}} catch (IOException ioe) {ioe.printStackTrace();throw new RuntimeException("Release resource failed.");}}

如上所示：url参数通过setRequestProperty方法放在请求头中 ，而文件流放在 body 中。

同时需要注意 HttpURLConnection.setChunkedStreamingMode 此方法保证每次文件流达到指定大小就发送一次，避免了放在缓存并一次性传输中可能遇到的数据缺失。

http://blog.csdn.net/z69183787/article/details/8186918 可参考

服务端：

public String underUpload() throws IOException{String data = request.getHeader("data"); String userInfo = request.getHeader("userInfo"); userInfo = new String(userInfo.getBytes("iso-8859-1"),"GBK");//System.out.println(data);//System.out.println(userInfo);Map<String,String> data_map = gson.fromJson(data,attachVo.data_map.getClass());if(data_map!=null) attachVo.data_map=data_map;attachVo.user = gson.fromJson(userInfo,attachVo.user.getClass());apiService.attachUpload(attachVo,new BufferedInputStream(request.getInputStream()));//response.setStatus(200);return null;}

使用的是ssh架构 ，通过getHeader 得到 url参数，通过getInputStream得到文件流，同时还要控制好编码，以防中文乱码。

至于断点续传，基本思想是通过信息头的部分 传递每次传输的文件大小，与服务器端的文件大小匹配。并通过

RandomAccessFile raFile = new RandomAccessFile(uploadFile.getAbsolutePath(), "rw");raFile.seek(uploadFile.length());

方法进行根据传输大小实时进行文件读写。

public static void saveFile(String destFilePathStr,String destFileName){try {File destFilePath = new File(destFilePathStr);if(!destFilePath.exists()){destFilePath.mkdirs();destFilePath = null;}File destFile = new File(destFilePathStr+"//"+destFileName);if(!destFile.exists()){destFile.createNewFile();}} catch (Exception e) {e.printStackTrace();}}public static long uploadFile(String offset,String destFileName,BufferedInputStream bis) throws IOException{File uploadFile = new File(destFileName);int len = 0;byte[] bt = new byte[1024];RandomAccessFile raFile = new RandomAccessFile(uploadFile.getAbsolutePath(), "rw");raFile.seek(uploadFile.length());    while ((len = bis.read(bt)) > 0){    raFile.write(bt, 0, len);    }    long l = raFile.length();    try {     if(bis != null)     bis.close();     if (raFile != null)     raFile.close();     } catch (IOException e) {l = 0;    e.printStackTrace();}return l ;}

首先创建一个空文件，接下来根据每次接收的文件流及文件长度 写入文件。