大文件文件分片上传

    /**
     * 前端可以参考百度的分片
     * 大文件分片上传
     * @param file              单次分片上传文件
     * @param chunk             当前分片数  起始值为0
     * @param totalChunkNumbers 文件总分片数
     * @param chunkSize         文件每片大小
     */
    public void chunkRandomAccessFile(File file, String fileName, int chunk, int totalChunkNumbers, int chunkSize ) {
        FileOutputStream tempFile = null;
        int donat = fileName.lastIndexOf(".");
        String subStringFile = fileName.substring(0, donat);
        try {
            FileInputStream source = new FileInputStream(file);
            String uploadPath = FILE_UPLOAD_TMP_PATH + "\\" + subStringFile + "tmp";
            File directory = new File(uploadPath);
            if (!directory.exists()) {
                directory.mkdirs(); // 创建路径
            }
            File uploadFile = new File(directory, subStringFile + "_" + chunk + ".tmp");
            tempFile = new FileOutputStream(uploadFile);
            byte[] bytes = source.readAllBytes();
            int length = bytes.length;
            //数据校验   前后台分片大小校验
            if (chunkSize != length || CHUNK_SIZE != chunkSize) {
                log.debug("分片非法!");
                return;
            }
            tempFile.write(bytes, 0, length);
            tempFile.flush();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (tempFile != null) {
                try {
                    tempFile.close();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
        }


        //合并文件
        if (chunk > 0 && totalChunkNumbers == chunk) {
            BufferedOutputStream bufferedOutputStream;
            try {
                File finalFile = new File(FILE_UPLOAD_TMP_PATH + "\\" + fileName);
                bufferedOutputStream = new BufferedOutputStream(new FileOutputStream(finalFile));
                int index = 0;
                for (int i = 0; i < totalChunkNumbers; i++) {
                    index++;
                    File tempFileSecond = new File(FILE_UPLOAD_TMP_PATH, subStringFile + "tmp\\" + subStringFile + "_" + index + ".tmp");
                    while (!tempFileSecond.exists()) {//断点续传
                        //并发情况下最后一个分片不一定先到  等一会
                        try {
                            Thread.sleep(100);
                        } catch (InterruptedException e) {
                            throw new RuntimeException(e);
                        }
                    }
                    FileInputStream fileInputStream = new FileInputStream(tempFileSecond);
                    byte[] tempByte = fileInputStream.readAllBytes();

                    bufferedOutputStream.write(tempByte);
                    fileInputStream.close();
                    //多次删除小文件会增加磁盘的负载和时间的消耗
//                        tempFileSecond.delete();
                    bufferedOutputStream.flush();
                }
            } catch (FileNotFoundException e) {
                throw new RuntimeException(e);
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
            if (bufferedOutputStream != null) {
                try {
                    bufferedOutputStream.close();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            File tempFolder = new File(FILE_UPLOAD_TMP_PATH, subStringFile + "tmp");
            deleteFolder(tempFolder);
        }


    }

    public void deleteFolder(File folder) {
        if (folder.isDirectory()) {
            File[] files = folder.listFiles();
            if (files != null) {
                for (File file : files) {
                    deleteFolder(file);
                }
            }
        }
        folder.delete();
    }

 

 private static final String FILE_PATH = "D:\\qqq\\1111.docx";
    private static final String FILE_UPLOAD_TMP_PATH = "D:\\qqq";
    private static final int CHUNK_SIZE = 14670;