这是我的Java程序
DT$ID2 <- sapply(regmatches(DT$ID, gregexpr("\\bUS\\S*", DT$ID)), toString)
查看Java程序输出的代码段。状态行显示为HTTP / 1.1 200 OK。但是，打印的标题字段与手动运行curl时得到的内容不匹配。它似乎是从第一个响应中获取标头值，而不是从最后一个响应中获取标头值。最后一个响应中出现的甚至更重要的“内容长度”字段也未设置响应结构。
private static final String SAMPLE_URL = "https://www.dropbox.com/s/<something>/test_out4.mp4";
public static void main(String[] args) throws IOException, URISyntaxException {
HttpClient client = HttpClientBuilder.create().build();
HttpHead request = new HttpHead(new URI(SAMPLE_URL));
HttpResponse response = client.execute(request);
System.out.println(response.getStatusLine());
for (Header header : response.getAllHeaders()) {
System.out.println(header.getName() + ": " + header.getValue());
}
}
当我运行curl时，输出正确。 HttpClient中是否有任何设置可以返回最新的标头？
HTTP/1.1 200 OK <<< Status is 200
Server: nginx
Date: Thu, 20 Jun 2019 02:22:58 GMT
Content-Type: text/html; charset=utf-8 << Content type is char
....
curl -I https://www.dropbox.com/s/<something>/test_out4.mp4
HTTP/1.1 301 Moved Permanently <<< Status 301
Server: nginx
Date: Thu, 20 Jun 2019 02:20:50 GMT
Content-Type: text/html; charset=utf-8 <<< Content type text
Connection: keep-alive
....
HTTP/1.1 302 Found << second redirect
Server: nginx
Date: Thu, 20 Jun 2019 02:36:03 GMT
Content-Type: text/html; charset=utf-8