java代码实现上传下载视频高效方法

实现上传下载视频的高效方法，可以考虑以下几点：

1. 使用多线程：多线程能够充分利用带宽，加快上传下载速度。可以使用Java的线程池来管理线程，避免线程过多导致系统资源耗尽。

2. 分块传输：将大文件分成若干个块进行传输，这样即使某一块传输失败，也不会影响整个文件的上传或下载。可以使用HTTP协议的分块传输编码（Chunked Transfer Encoding）或者自定义分块传输协议。

3. 压缩数据：对于大文件，可以在传输时进行压缩，减少传输数据量。可以使用Java的压缩库（如GZIP）进行压缩。

4. 使用CDN：通过使用CDN（内容分发网络），可以将静态资源缓存到离用户最近的节点上，加速文件的传输。

下面是Java代码实现上传下载视频的示例：

上传视频：

File file = new File("video.mp4");
String url = "http://example.com/upload";
CloseableHttpClient httpClient = HttpClients.createDefault();
HttpPost httpPost = new HttpPost(url);

//分块上传
FileEntity fileEntity = new FileEntity(file, ContentType.DEFAULT_BINARY);
httpPost.setEntity(fileEntity);

//设置多线程上传
ExecutorService executorService = Executors.newFixedThreadPool(5); //开启5个线程
List<Future> futures = new ArrayList<>();
for (int i = 0; i < 5; i++) { //将文件分成5块并上传
    final int partNumber = i+1;
    final long start = i * file.length() / 5;
    final long end = (i+1) * file.length() / 5 - 1;
    Future<?> future = executorService.submit(() -> {
        HttpPost httpPartPost = new HttpPost(url);
        httpPartPost.setHeader("Content-Range", "bytes " + start + "-" + end + "/" + file.length());
        httpPartPost.setEntity(new FileEntity(file, ContentType.DEFAULT_BINARY, start, end));
        CloseableHttpResponse response = httpClient.execute(httpPartPost);
        response.close();
    });
    futures.add(future);
}

//等待所有线程上传完成
for (Future future : futures) {
    try {
        future.get();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

executorService.shutdown();
httpClient.close();

下载视频：

String url = "http://example.com/video.mp4";
CloseableHttpClient httpClient = HttpClients.createDefault();
HttpGet httpGet = new HttpGet(url);

//设置多线程下载
ExecutorService executorService = Executors.newFixedThreadPool(5); //开启5个线程
List<Future> futures = new ArrayList<>();
CloseableHttpResponse response = httpClient.execute(httpGet);
long contentLength = Long.parseLong(response.getFirstHeader("Content-Length").getValue());
for (int i = 0; i < 5; i++) { //将文件分成5块并下载
    final int partNumber = i+1;
    final long start = i * contentLength / 5;
    final long end = (i+1) * contentLength / 5 - 1;
    Future<?> future = executorService.submit(() -> {
        HttpGet httpPartGet = new HttpGet(url);
        httpPartGet.setHeader("Range", "bytes=" + start + "-" + end);
        CloseableHttpResponse partResponse = httpClient.execute(httpPartGet);
        HttpEntity entity = partResponse.getEntity();
        InputStream inputStream = entity.getContent();
        FileOutputStream fileOutputStream = new FileOutputStream("video_" + partNumber + ".mp4");
        byte[] buffer = new byte[1024];
        int len;
        while ((len = inputStream.read(buffer)) != -1) {
            fileOutputStream.write(buffer, 0, len);
        }
        fileOutputStream.close();
        inputStream.close();
        partResponse.close();
    });
    futures.add(future);
}

//等待所有线程下载完成
for (Future future : futures) {
    try {
        future.get();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

executorService.shutdown();
httpClient.close();