Setting custom HTTP request headers in an URL object doesn't work

Question

I am trying to fetch an image from an IP camera using HTTP. The camera requires HTTP basic authentication, so I have to add the corresponding request header:

URL url = new URL("http://myipcam/snapshot.jpg");
URLConnection uc = url.openConnection();
uc.setRequestProperty("Authorization", 
  "Basic " + new String(Base64.encode("user:pass".getBytes())));

// outputs "null"
System.out.println(uc.getRequestProperty("Authorization"));

I am later passing the url object to ImageIO.read(), and, as you can guess, I am getting an HTTP 401 Unauthorized, although user and pass are correct.

What am I doing wrong?

I've also tried new URL("http://user:pass@myipcam/snapshot.jpg"), but that doesn't work either.

score 3 · Answer 1 · answered Jun 24 '11 at 15:03

In class sun.net.www.protocol.http.HttpURLConnection, which extends java.net.HttpURLConnection, the following method getRequestProperty(String key) was overridden to return null when requesting security sensitive information.

public String getRequestProperty(String key) {
    // don't return headers containing security sensitive information
    if (key != null) {
        for (int i = 0; i < EXCLUDE_HEADERS.length; i++) {
        if (key.equalsIgnoreCase(EXCLUDE_HEADERS[i])) {
            return null;
        }
        }
    }
    return requests.findValue(key);
}

Here is the declaration for EXCLUDE_HEADERS:

// the following http request headers should NOT have their values
// returned for security reasons.
private static final String[] EXCLUDE_HEADERS = {
    "Proxy-Authorization", "Authorization" };

That's why you're having a null on uc.getRequestProperty("Authorization"). Have you tried using HttpClient from Apache?

Thank you, now I understand the reason for getting `null`. But why does it return HTTP 401? Is it possible that the "Authorization" property is not set at all? — Blagovest Buyukliev, Jun 24 '11 at 15:07
@Blagovest Buyukliev, if `uc extends HttpURLConnection` then typecast it to `HttpURLConnection` and get the `InputStream` of the error by calling `getErrorStream()`. That contains the message of the HTTP 401 error. Other than that, I can't help you. — Buhake Sindi, Jun 27 '11 at 05:16

score 2 · Accepted Answer · answered Jun 27 '11 at 09:00

2

Issue resolved. It didn't work because I was passing url to ImageIO.read().

Instead, passing uc.getInputStream() got it working.

answered Jun 27 '11 at 09:00

Blagovest Buyukliev

42,498
14
94
130

score 0 · Answer 3 · answered Jun 24 '11 at 15:13

0

Have you tried to subclass URLConnection or HttpURLConnection and override the getRequestProperty() method?

answered Jun 24 '11 at 15:13

William Niu

15,798
7
53
93

I tried `HttpURLConnection uc = (HttpURLConnection) url.openConnection()`, but the outcome is the same. My problem is not actually with `getRequestProperty`, but with the unsent Authorization header. – Blagovest Buyukliev Jun 24 '11 at 15:17
then perhaps override the `openConnection` method? – William Niu Jun 24 '11 at 15:25

Setting custom HTTP request headers in an URL object doesn't work

3 Answers3