Springboot分片上传

 public static void main(String[] args) throws IOException {

    File sourceFile = new File("D:\\44.mp4");
    String chunkFolder = "D:\\IDM\\videos\\chunks\\";
    File f = new File(chunkFolder);
    if (!f.exists()){
        f.mkdirs();
    }
    long shareSize = 1024 * 1024 * 10; // 分片的大小，单位为字节
    System.out.println("分片大小: "   shareSize);

    try (RandomAccessFile randomAccessFileReader = new RandomAccessFile(sourceFile, "r");FileChannel fileChannelReader = randomAccessFileReader.getChannel()) {
        ByteBuffer buffer = ByteBuffer.allocate(1024);

        long total = (long) Math.ceil(sourceFile.length() * 1.0 / shareSize);
        System.out.println("分片总数: "   total);

        for (int i = 0; i < total; i  ) {
            File chunkFile = new File(chunkFolder   i);
            System.out.println("分片: "   (i   1)   ", chunkFile: "   chunkFile.getName());

            try (RandomAccessFile randomAccessFileWriter = new RandomAccessFile(chunkFile, "rw");
                 FileChannel fileChannelWriter = randomAccessFileWriter.getChannel()) {
                int len;
                buffer.clear();
                while ((len=fileChannelReader.read(buffer)) != -1) {
                    //改为读模式
                    buffer.flip();
                    fileChannelWriter.write(buffer);
                    //改为写模式
                    buffer.compact();
                    //如果分片的大小>=分片的大小，读下一块
                    if (chunkFile.length() >= shareSize) {
                        break;
                    }
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    } catch (IOException e) {
        e.printStackTrace();
    }
    //合并文件
    mergeFile(new File(chunkFolder));
}


 /**
 * 合并块文件
 * @param chunkFolder
 */
public static void mergeFile(File chunkFolder) throws IOException {
    //块文件夹下文件列表
    File[] files = chunkFolder.listFiles();
    assert files != null;
    List<File> fileList = Arrays.stream(files).sorted(
            Comparator.comparing(o -> Long.valueOf(o.getName())))
            .collect(Collectors.toList());
    //合并的文件
    File mergeFile = new File("D:\\IDM\\videos\\chunks\\java_merge.mp4");
    //创建新文件
    boolean success = mergeFile.createNewFile();
    //创建写对象
    RandomAccessFile randomAccessFileWriter = new RandomAccessFile(mergeFile, "rw");
    byte[] bytes = new byte[1024];
    for (int i = 0; i < fileList.size(); i  ) {
        File chunkFile = fileList.get(i);
        logger.info("合并------>分片:{},chunkFile:{}", i   1, chunkFile.getName());
        RandomAccessFile randomAccessFileReader = new RandomAccessFile(chunkFile, "r");
        int len;
        while ((len = randomAccessFileReader.read(bytes)) != -1) {
            randomAccessFileWriter.write(bytes, 0, len);
        }
        randomAccessFileReader.close();
    }
    randomAccessFileWriter.close();
    Arrays.stream(files).forEach( f->{
        f.delete();
    } );
}

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