分段上传文件

上传文件

 public static final int COUNT = 5;
  public static final int BUFFER_SIZE = 1024 * 8;

public File mergeFile(File mergeFile, MultipartFile partFile, long startPosition) {

        RandomAccessFile randomAccessFile;
        try {
            randomAccessFile = new RandomAccessFile(mergeFile, "rw");
            randomAccessFile.seek(startPosition);
            byte[] buffer = new byte[BUFFER_SIZE];
            InputStream input = partFile.getInputStream();
            BufferedInputStream in = new BufferedInputStream(input, BUFFER_SIZE);
            int len;
            try {
                while ((len = in.read(buffer, 0, BUFFER_SIZE)) != -1) {
                    randomAccessFile.write(buffer, 0, len);
                }
            } finally {
                in.close();
                input.close();
                randomAccessFile.close();
            }
            return mergeFile;
        } catch (Exception e) {
            return null;
        }
    }

private static File newPartFileWithLength(File originFile, long startPosition,
                                              long fileLength, String partFileDir,
                                              String fileName) {
        String name = partFileDir + File.separator + fileName;
        File file = new File(name);

        RandomAccessFile randomAccessFile;
        try {
            randomAccessFile = new RandomAccessFile(originFile, "rw");
            randomAccessFile.seek(startPosition);
            byte[] buffer = new byte[BUFFER_SIZE];
            FileOutputStream output = new FileOutputStream(file);
            BufferedOutputStream out = new BufferedOutputStream(output, BUFFER_SIZE);
            int len;
            try {
                while ((len = randomAccessFile.read(buffer, 0, Math.min((int) (fileLength - file.length()), BUFFER_SIZE))) != -1
                && file.length() < fileLength) {
                    out.write(buffer, 0, len);
                    out.flush();
                }
            } finally {
                IOUtils.closeQuietly(out);
                IOUtils.closeQuietly(output);
                IOUtils.closeQuietly(randomAccessFile);
            }

            return file;
        } catch (Exception e) {
            return null;
        }
    }