gradle依賴

//hadoop
compile("org.apache.hadoop:hadoop-client:3.3.1")

HdfsUtil類

public class HdfsUtil
{
    private FileSystem fileSystem;

    public HdfsUtil()
    {
        init();
    }

    private void init()
    {
        Configuration configuration = new Configuration();
        try
        {
            fileSystem = FileSystem.get(new URI("hdfs://IP:PORT"), configuration, "op");
        }
        catch (IOException e)
        {
            log.error(e.getMessage());
            log.error("HDFS連接異常");
        }
        catch (InterruptedException e)
        {
            log.error(e.getMessage());
            log.error("HDFS中斷異常");
        }
        catch (URISyntaxException e)
        {
            log.error(e.getMessage());
            log.error("URI語法異常");
        }
    }
}

讀取二進(jìn)制文件方法類

public byte[] downloadFile(String path)
    {
        byte[] b = null;
        try
        {
            //獲取文件
            FSDataInputStream fsDataInputStream = fileSystem.open(new Path(path));
            BufferedInputStream bufferedInputStream = new BufferedInputStream(fsDataInputStream);
            //設(shè)置byte長(zhǎng)度
            int len = bufferedInputStream.available();
            b = new byte[len];
            //賦值
            bufferedInputStream.read(b);
            bufferedInputStream.close();
            fsDataInputStream.close();
            fileSystem.close();
        }
        catch (IOException e)
        {
            log.error(e.getMessage());
            log.error("獲取HDFS文件失敗");
        }
        return b;
    }

提供下載接口

    @GetMapping("URL")
    public ResponseEntity<Object> downFileHdfs(@PathVariable String fileName)
    {
        HdfsUtil hdfsUtil = new HdfsUtil();
        byte[] content = hdfsUtil.downloadFile("path"+fileName);
        if (content == null)
        {
            return null;
        }
        HttpHeaders headers = new HttpHeaders();
        headers.add("Content-Disposition", String.format("attachment;filename=%s",fileName));
        headers.add("Cache-Control", "no-cache,no-store,must-revalidate");
        headers.add("Pragma", "no-cache");
        headers.add("Expires", "0");
        ResponseEntity<Object> responseEntity = ResponseEntity.ok()
                .headers(headers)
                //設(shè)置長(zhǎng)度
                .contentLength(content.length)
                .contentType(MediaType.parseMediaType("application/octet-stream"))
                //因?yàn)榉椒ㄊ欠盒?，所以直接傳?                .body(content);
        return responseEntity;
    }