怎么用Java下载m3u8

在Java中下载M3U8格式的流媒体文件通常需要分步骤处理，因为M3U8是HLS（HTTP Live Streaming）的一种manifest文件，它包含了多个小片段(medias)的URL。以下是一个简单的示例，展示如何使用Java的`HttpURLConnection`或第三方库如`Apache HttpClient`来逐段下载：

1. **使用HttpURLConnection:**

import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class M3U8Downloader {
    private static final int BUFFER_SIZE = 1024 * 10; // 缓冲区大小

    public void downloadM3U8(String m3u8Url) throws Exception {
        URL url = new URL(m3u8Url);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("GET");
        
        if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
            throw new RuntimeException("Failed to fetch M3U8 playlist. Response Code: " + connection.getResponseCode());
        }

        InputStream inputStream = connection.getInputStream();
        String line;
        StringBuilder mediaList = new StringBuilder();

        while ((line = inputStream.readLine()) != null) {
            // 检查是否是media链接
            if (line.startsWith("#EXTINF")) {
                // 从#EXTINF开始直到第一个逗号获取时长
                int endOfInfo = line.indexOf(",");
                String mediaUrl = line.substring(endOfInfo + 1).trim();
                downloadMedia(mediaUrl);
            } else {
                mediaList.append(line);
            }
        }

        inputStream.close();
        connection.disconnect();
    }

    // 下载单个media片段的方法
    private void downloadMedia(String mediaUrl) throws Exception {
        URL media = new URL(mediaUrl);
        HttpURLConnection mediaConnection = (HttpURLConnection) media.openConnection();
        mediaConnection.setRequestMethod("GET");
        // ...下载并保存到本地
    }
}

**使用Apache HttpClient:**

import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;

public class M3U8Downloader {
    public void downloadM3U8(String m3u8Url) throws Exception {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpGet httpGet = new HttpGet(m3u8Url);
        
        try (CloseableHttpResponse response = httpClient.execute(httpGet)) {
            if (response.getStatusLine().getStatusCode() != 200) {
                throw new RuntimeException("Failed to fetch M3U8 playlist. Status Code: " + response.getStatusLine().getStatusCode());
            }

            // ...解析响应内容并下载每个media片段
        }
        httpClient.close();
    }
}