视频分段下载（视频可滑动播放）

java

JAVA源码

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.util.Date;
/**
 * 视频分段下载
 *
 * @param request
 * @param response
 * @param fileName
 */
public void downloadVideo(HttpServletRequest request, HttpServletResponse response, String fileName, File file) {
    RandomAccessFile randomFile = null;
    ServletOutputStream out = null;
    try {

        //只读模式
        randomFile = new RandomAccessFile(file, "r");

        long contentLength = randomFile.length();
        String range = request.getHeader("Range");
        int start = 0, end = 0;
        if (range != null && range.startsWith("bytes=")) {
            String[] values = range.split("=")[1].split("-");
            start = Integer.parseInt(values[0]);
            if (values.length > 1) {
                end = Integer.parseInt(values[1]);
            }
        }
        int requestSize = 0;
        if (end != 0 && end > start) {
            requestSize = end - start + 1;
        } else {
            requestSize = Integer.MAX_VALUE;
        }

        response.setContentType("video/mp4");
        response.setHeader("Accept-Ranges", "bytes");
        response.setHeader("ETag", fileName);
        response.setHeader("Last-Modified", new Date().toString());
        //第一次请求只返回content length来让客户端请求多次实际数据
        if (range == null) {
            response.setHeader("Content-length", contentLength + "");
        } else {
            //以后的多次以断点续传的方式来返回视频数据
            response.setStatus(HttpServletResponse.SC_PARTIAL_CONTENT);//206
            long requestStart = 0, requestEnd = 0;
            String[] ranges = range.split("=");
            if (ranges.length > 1) {
                String[] rangeDatas = ranges[1].split("-");
                requestStart = Integer.parseInt(rangeDatas[0]);
                if (rangeDatas.length > 1) {
                    requestEnd = Integer.parseInt(rangeDatas[1]);
                }
            }
            long length = 0;
            if (requestEnd > 0) {
                length = requestEnd - requestStart + 1;
                response.setHeader("Content-length", "" + length);
                response.setHeader("Content-Range", "bytes " + requestStart + "-" + requestEnd + "/" + contentLength);
            } else {
                length = contentLength - requestStart;
                response.setHeader("Content-length", "" + length);
                response.setHeader("Content-Range", "bytes " + requestStart + "-" + (contentLength - 1) + "/" + contentLength);
            }
        }

        out = response.getOutputStream();
        int needSize = requestSize;

        //设置文件指针偏移量
        randomFile.seek(start);
        while (needSize > 0) {
            byte[] buffer = new byte[4096];
            int len = randomFile.read(buffer);
            if (needSize < buffer.length) {
                out.write(buffer, 0, needSize);
            } else {
                out.write(buffer, 0, len);
                if (len < buffer.length) {
                    break;
                }
            }
            needSize -= buffer.length;
        }
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try {
            if (randomFile != null) {
                randomFile.close();
            }
            if (out != null) {
                out.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

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最后编辑时间为: 2022/06/29 18:00