下载索引文件

public String getIndexFile() throws Exception{
    URL url = new URL(originUrlpath);
    //下载资源
    BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream(),"UTF-8"));

    String content = "" ;
    String line;
    while ((line = in.readLine()) != null) {
        content += line + "\n";
    }
    in.close();

    return content;
}

解析索引文件

public List analysisIndex(String content) throws Exception{
    Pattern pattern = Pattern.compile(".*ts");
    Matcher ma = pattern.matcher(content);

    List<String> list = new ArrayList<String>();

    while(ma.find()){
        list.add(ma.group());
    }

    return list;
}

下载视频片段

同步下载

public HashMap downLoadIndexFile(List<String> urlList){
    HashMap<Integer,String> keyFileMap = new HashMap<>();

    for(int i =0;i<urlList.size();i++){
        String subUrlPath = urlList.get(i);
        String fileOutPath = folderPath + File.separator + i + ".ts";
        keyFileMap.put(i, fileOutPath);
        try{
            downloadNet(preUrlPath + subUrlPath, fileOutPath);

            System.out.println("成功："+ (i + 1) +"/" + urlList.size());
        }catch (Exception e){
            System.err.println("失败："+ (i + 1) +"/" + urlList.size());
        }
    }

    return  keyFileMap;
}

private void downloadNet(String fullUrlPath, String fileOutPath) throws Exception {

    //int bytesum = 0;
    int byteread = 0;

    URL url = new URL(fullUrlPath);
    URLConnection conn = url.openConnection();
    InputStream inStream = conn.getInputStream();
    FileOutputStream fs = new FileOutputStream(fileOutPath);

    byte[] buffer = new byte[1204];
    while ((byteread = inStream.read(buffer)) != -1) {
        //bytesum += byteread;
        fs.write(buffer, 0, byteread);
    }
}

多线程下载

public void downLoadIndexFileAsync(List<String> urlList, HashMap<Integer,String> keyFileMap) throws Exception{
    int downloadForEveryThread = (urlList.size() + threadQuantity - 1)/threadQuantity;
    if(downloadForEveryThread == 0) downloadForEveryThread = urlList.size();

    for(int i=0; i<urlList.size();i+=downloadForEveryThread){
        int startIndex = i;
        int endIndex = i + downloadForEveryThread - 1;
        if(endIndex >= urlList.size())
            endIndex = urlList.size() - 1;

        new DownloadThread(urlList, startIndex, endIndex, keyFileMap).start();
    }
}

class DownloadThread extends Thread{
    private List<String> urlList;
    private int startIndex;
    private int endIndex;
    private HashMap<Integer,String> keyFileMap;

    public DownloadThread(List<String> urlList, int startIndex, int endIndex, HashMap<Integer,String> keyFileMap){
        this.urlList = urlList;
        this.startIndex = startIndex;
        this.endIndex = endIndex;
        this.keyFileMap = keyFileMap;
    }
    @Override
    public void run(){
        for(int i=startIndex;i<=endIndex;i++){
            String subUrlPath = urlList.get(i);
            String fileOutPath = folderPath + File.separator + i + ".ts";
            keyFileMap.put(i, fileOutPath);
            String message = "%s: 线程 " + (startIndex/(endIndex - startIndex) + 1)
                    + ", "+ (i + 1) +"/" + urlList.size() +", 合计: %d";
            try{
                downloadNet(preUrlPath + subUrlPath, fileOutPath);

                System.out.println(String.format(message, "成功", keyFileMap.size()));
            }catch (Exception e){
                System.err.println(String.format(message, "失败", keyFileMap.size()));
            }
        }
    }
}

视频片段合成

public String composeFile(HashMap<Integer,String> keyFileMap) throws Exception{

    if(keyFileMap.isEmpty()) return null;

    String fileOutPath = rootPath + File.separator + fileName;
    FileOutputStream fileOutputStream = new FileOutputStream(new File(fileOutPath));
    byte[] bytes = new byte[1024];
    int length = 0;
    for(int i=0; i<keyFileMap.size(); i++){
        String nodePath = keyFileMap.get(i);
        File file = new File(nodePath);
        if(!file.exists())  continue;

        FileInputStream fis = new FileInputStream(file);
        while ((length = fis.read(bytes)) != -1) {
            fileOutputStream.write(bytes, 0, length);
        }
    }

    return fileName;
}

开源地址：hlsdownloader

参考：M3U8在线视频文件下载合成MP4视频

Java 下载 HLS (m3u8) 视频

原文：https://www.cnblogs.com/victorbu/p/10347663.html