使用http range实现断点续传(服务器端):
public void downRangeFile(
File downloadFile,
HttpServletResponse response,
HttpServletRequest request) {
InputStream inputStream = null;
ServletOutputStream out = null;
response.reset();
try {
int fSize = Integer.parseInt(String.valueOf(downloadFile.length()));
response.setCharacterEncoding("utf-8");
response.setContentType("application/x-download");
response.addHeader("Content-Type", "audio/mpeg");
response.setHeader("Accept-Ranges", "bytes");
response.setHeader("Content-Length", String.valueOf(fSize));
response.setHeader("Access-Control-Allow-Origin", "*");
inputStream = new FileInputStream(downloadFile);
long p = 0;
long l = 0;
l = fSize;
//如果是第一次下,还没有断点续传,状态是默认的 200,无需显式设置
//响应的格式是:
//HTTP/1.1 200 OK
if (request.getHeader("Range") != null) //客户端请求的下载的文件块的开始字节
{
String rangeString = request.getHeader("Range");
logger.log(Level.INFO, "Range==", request.getHeader("Range"));
//如果是下载文件的范围而不是全部,向客户端声明支持并开始文件块下载
//要设置状态
//响应的格式是:
//HTTP/1.1 206 Partial Content
response.setStatus(javax.servlet.http.HttpServletResponse.SC_PARTIAL_CONTENT);//206
//从请求中得到开始的字节
//请求的格式是:
//Range: bytes=[文件块的开始字节]-
p = Long.parseLong((request.getHeader("Range").replaceAll("bytes=", "").split("-")[0]));
}
logger.log(Level.INFO, "p==", p);
logger.log(Level.INFO, "l==", l);
//下载的文件(或块)长度
//响应的格式是:
//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(l - p).toString());
if (p != 0) {
//不是从最开始下载,
//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]
response.setHeader("Content-Range", "bytes " + new Long(p).toString() + "-" + new Long(l - 1).toString() + "/" + new Long(l).toString());
} else {
response.setHeader("Content-Range", "bytes " + new Long(0).toString() + "-" +