java 播放视屏文件分片加载

文件分片播放，方便测试工具代码如下：

import org.apache.catalina.connector.ClientAbortException;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RequestHeader;

import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.BufferedOutputStream;

import java.io.File;

import java.io.IOException;

import java.io.RandomAccessFile;

@Controller

@RequestMapping(value = "/upload/main/")

public class Main {

@RequestMapping("test/{name}/{hz}")

public void home(@PathVariable("name") String name, @PathVariable("hz") String hz, HttpServletRequest request,

HttpServletResponse response, @RequestHeader(required = false) String range) {

// 文件位置

File music = new File("D:\\Temp\\patch\\2020-04-14\\" + name + "." + hz);

// 开始下载位置

long startByte = 0;

// 结束下载位置

long endByte = music.length() - 1;

// 有range的话

if (range != null && range.contains("bytes=") && range.contains("-")) {

// 坑爹地方一：http状态码要为206

response.setStatus(HttpServletResponse.SC_PARTIAL_CONTENT);

range = range.substring(range.lastIndexOf("=") + 1).trim();

String[] ranges = range.split("-");

try {

//判断range的类型

if (ranges.length == 1) {

//类型一：bytes=-2343

if (range.startsWith("-")) {

endByte = Long.parseLong(ranges[0]);

}

//类型二：bytes=2343-

else if (range.endsWith("-")) {

startByte = Long.parseLong(ranges[0]);

}

}

//类型三：bytes=22-2343

else if (ranges.length == 2) {

startByte = Long.parseLong(ranges[0]);

endByte = Long.parseLong(ranges[1]);

}

} catch (NumberFormatException e) {

startByte = 0;

endByte = music.length() - 1;

}

} else {

//没有ranges即全部一次性传输，需要用200状态码，这一行应该可以省掉，因为默认返回是200状态码

response.setStatus(HttpServletResponse.SC_OK);

}

//要下载的长度(endByte为总长度-1，这时候要加回去)

long contentLength = endByte - startByte + 1;

//文件名

String fileName = music.getName();

//文件类型

String contentType = request.getServletContext().getMimeType(fileName);

//各种响应头设置

//参考资料：https://www.ibm.com/developer...

//坑爹地方二：看代码

response.setHeader("Accept-Ranges", "bytes");

response.setContentType(contentType);

response.setHeader("Content-Type", contentType);

//这里文件名换你想要的，inline表示浏览器可以直接使用(比如播放音乐，我方便测试用的)

//参考资料：http://hw1287789687.iteye.com...

response.setHeader("Content-Disposition", "inline;filename=test.mp4");

response.setHeader("Content-Length", String.valueOf(contentLength));

//坑爹地方三：Content-Range，格式为

// [要下载的开始位置]-[结束位置]/[文件总大小]
外汇隔夜利息http://www.fx61.com/interest....

response.setHeader("Content-Range", "bytes " + startByte + "-" + endByte + "/" + music.length());

BufferedOutputStream outputStream = null;

RandomAccessFile randomAccessFile = null;

//已传送数据大小

long transmitted = 0;

try {

randomAccessFile = new RandomAccessFile(music, "r");

outputStream = new BufferedOutputStream(response.getOutputStream());

byte[] buff = new byte[4096];

int len = 0;

randomAccessFile.seek(startByte);

//坑爹地方四：判断是否到了最后不足4096(buff的length)个byte这个逻辑((transmitted + len) <= contentLength)要放前面!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

//不然会先读取randomAccessFile，造成后面读取位置出错，找了一天才发现问题所在

while ((transmitted + len) <= contentLength && (len = randomAccessFile.read(buff)) != -1) {

outputStream.write(buff, 0, len);

transmitted += len;

//停一下，方便测试(本地下载传输速度特别快，没反应过来就下载好了)，实际生产环境中用的时候需要删除这一行

Thread.sleep(10);

}

//处理不足buff.length部分

if (transmitted < contentLength) {

len = randomAccessFile.read(buff, 0, (int) (contentLength - transmitted));

outputStream.write(buff, 0, len);

transmitted += len;

}

outputStream.flush();

response.flushBuffer();

randomAccessFile.close();

System.out.println("下载完毕：" + startByte + "-" + endByte + "：" + transmitted);

} catch (ClientAbortException e) {

System.out.println("用户停止下载：" + startByte + "-" + endByte + "：" + transmitted);

//捕获此异常表示拥护停止下载

} catch (IOException | InterruptedException e) {

e.printStackTrace();

} finally {

try {

if (randomAccessFile != null) {

randomAccessFile.close();

}

} catch (IOException e) {

e.printStackTrace();

}

}

}

}