java播放视频支持进度条拖拽

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需求是这样的,公司要求我实现一个视频播放功能
我用以下代码实现了视频播放

<video width="320" height="240">
    <source src="movie.mp4" type="video/mp4">
</video>

视频播放功能实现了
但是测试的时候发现,拖动进度条竟然没有效果

image.png

思前想后觉得视频播放支持滚动条应该与文件下载支持暂停差不多,都是要用断点续传的方式实现,所以朝着这个方向努力了一下,轻松搞定

直接上代码,通过video的src请求

/**
 * video请求位置
 * 
 * @param request
 * @param response
 */
@RequestMapping(value = "/player", method = RequestMethod.GET)
public void player(HttpServletRequest request, HttpServletResponse response) {
	String path = request.getServletContext().getRealPath("/static/my/video/test.mp4");
	BufferedInputStream bis = null;
	try {
		File file = new File(path);
		if (file.exists()) {
			long p = 0L;
			long toLength = 0L;
			long contentLength = 0L;
			int rangeSwitch = 0; // 0,从头开始的全文下载;1,从某字节开始的下载(bytes=27000-);2,从某字节开始到某字节结束的下载(bytes=27000-39000)
			long fileLength;
			String rangBytes = "";
			fileLength = file.length();

			// get file content
			InputStream ins = new FileInputStream(file);
			bis = new BufferedInputStream(ins);

			// tell the client to allow accept-ranges
			response.reset();
			response.setHeader("Accept-Ranges", "bytes");

			// client requests a file block download start byte
			String range = request.getHeader("Range");
			if (range != null && range.trim().length() > 0 && !"null".equals(range)) {
				response.setStatus(javax.servlet.http.HttpServletResponse.SC_PARTIAL_CONTENT);
				rangBytes = range.replaceAll("bytes=", "");
				if (rangBytes.endsWith("-")) { // bytes=270000-
					rangeSwitch = 1;
					p = Long.parseLong(rangBytes.substring(0, rangBytes.indexOf("-")));
					contentLength = fileLength - p; // 客户端请求的是270000之后的字节(包括bytes下标索引为270000的字节)
				} else { // bytes=270000-320000
					rangeSwitch = 2;
					String temp1 = rangBytes.substring(0, rangBytes.indexOf("-"));
					String temp2 = rangBytes.substring(rangBytes.indexOf("-") + 1, rangBytes.length());
					p = Long.parseLong(temp1);
					toLength = Long.parseLong(temp2);
					contentLength = toLength - p + 1; // 客户端请求的是 270000-320000 之间的字节
				}
			} else {
				contentLength = fileLength;
			}

			// 如果设设置了Content-Length,则客户端会自动进行多线程下载。如果不希望支持多线程,则不要设置这个参数。
			// Content-Length: [文件的总大小] - [客户端请求的下载的文件块的开始字节]
			response.setHeader("Content-Length", new Long(contentLength).toString());

			// 断点开始
			// 响应的格式是:
			// Content-Range: bytes [文件块的开始字节]-[文件的总大小 - 1]/[文件的总大小]
			if (rangeSwitch == 1) {
				String contentRange = new StringBuffer("bytes ").append(new Long(p).toString()).append("-")
						.append(new Long(fileLength - 1).toString()).append("/")
						.append(new Long(fileLength).toString()).toString();
				response.setHeader("Content-Range", contentRange);
				bis.skip(p);
			} else if (rangeSwitch == 2) {
				String contentRange = range.replace("=", " ") + "/" + new Long(fileLength).toString();
				response.setHeader("Content-Range", contentRange);
				bis.skip(p);
			} else {
				String contentRange = new StringBuffer("bytes ").append("0-").append(fileLength - 1).append("/")
						.append(fileLength).toString();
				response.setHeader("Content-Range", contentRange);
			}

			String fileName = file.getName();
			response.setContentType("application/octet-stream");
			response.addHeader("Content-Disposition", "attachment;filename=" + fileName);

			OutputStream out = response.getOutputStream();
			int n = 0;
			long readLength = 0;
			int bsize = 1024;
			byte[] bytes = new byte[bsize];
			if (rangeSwitch == 2) {
				// 针对 bytes=27000-39000 的请求,从27000开始写数据
				while (readLength <= contentLength - bsize) {
					n = bis.read(bytes);
					readLength += n;
					out.write(bytes, 0, n);
				}
				if (readLength <= contentLength) {
					n = bis.read(bytes, 0, (int) (contentLength - readLength));
					out.write(bytes, 0, n);
				}
			} else {
				while ((n = bis.read(bytes)) != -1) {
					out.write(bytes, 0, n);
				}
			}
			out.flush();
			out.close();
			bis.close();
		}
	} catch (IOException ie) {
		// 忽略 ClientAbortException 之类的异常
	} catch (Exception e) {
		e.printStackTrace();
	}
}