我想发布一个大视频(近1 GB).
我正在使用FTP将视频发送到服务器,但上传会在一段时间后停止.在服务器上视频崩溃,但我可以上传较小的视频.
我还使用HTTP将视频发送到服务器,作为Base64编码字符串发送,但编码时出现内存不足异常.
解决方法
使用HTTP POST,并将内容发布为
Form-based File Upload(mime类型：multipart / form-data).该系统是Web上的标准,用于发送表单和/或上载文件.
使用HTTP chunked post模式,因此不需要预先知道大小,并且您可以以小部分流式传输任何文件.您仍然必须在服务器上(例如在PHP中)制作一些代码来接受该文件并执行所需的操作.
使用HttpURLConnection启动连接.然后使用我附加的类发送数据.它将创建正确的标题等,您将使用它作为OutputStream将原始数据写入其中,然后调用close,您就完成了.您可以覆盖其onHandleResult来处理生成的错误代码.
public class FormDataWriter extends FilterOutputStream{
private final HttpURLConnection con;
/**
* @param formName name of form in which data are sent
* @param fileName
* @param fileSize size of file,or -1 to use chunked encoding
*/
FormDataWriter(HttpURLConnection con,String formName,String fileName,long fileSize) throws IOException{
super(null);
this.con = con;
con.setDoOutput(true);
String boundary = generateBoundary();
con.setRequestProperty(HTTP.CONTENT_TYPE,"multipart/form-data; charset=UTF-8; boundary="+boundary);
{
StringBuilder sb = new StringBuilder();
writePartHeader(boundary,formName,fileName==null ? null : "filename=\""+fileName+"\"","application/octet-stream",sb);
headerBytes = sb.toString().getBytes("UTF-8");
sb = new StringBuilder();
sb.append("\r\n");
sb.append("--"+boundary+"--\r\n");
footerBytes = sb.toString().getBytes();
}
if(fileSize!=-1) {
fileSize += headerBytes.length + footerBytes.length;
con.setFixedLengthStreamingMode((int)fileSize);
}else
con.setChunkedStreamingMode(0x4000);
out = con.getOutputStream();
}
private byte[] headerBytes,footerBytes;
private String generateBoundary() {
StringBuilder sb = new StringBuilder();
Random rand = new Random();
int count = rand.nextInt(11) + 30;
int N = 10+26+26;
for(int i=0; i<count; i++) {
int r = rand.nextInt(N);
sb.append((char)(r<10 ? '0'+r : r<36 ? 'a'+r-10 : 'A'+r-36));
}
return sb.toString();
}
private void writePartHeader(String boundary,String name,String extraContentDispositions,String contentType,StringBuilder sb) {
sb.append("--"+boundary+"\r\n");
sb.append("Content-Disposition: form-data; charset=UTF-8; name=\""+name+"\"");
if(extraContentDispositions!=null)
sb.append("; ").append(extraContentDispositions);
sb.append("\r\n");
if(contentType!=null)
sb.append("Content-Type: "+contentType+"\r\n");
sb.append("\r\n");
}
@Override
public void write(byte[] buffer,int offset,int length) throws IOException{
if(headerBytes!=null) {
out.write(headerBytes);
headerBytes = null;
}
out.write(buffer,offset,length);
}
@Override
public void close() throws IOException{
flush();
if(footerBytes!=null) {
out.write(footerBytes);
footerBytes = null;
}
super.close();
int code = con.getResponseCode();
onHandleResult(code);
}
protected void onHandleResult(int code) throws IOException{
if(code!=200 && code!=201)
throw new IOException("Upload error code: "+code);
}
}
