Re: HttpURLConnection locks up on connect()

From:
"phillip.s.powell@gmail.com" <phillip.s.powell@gmail.com>
Newsgroups:
comp.lang.java.help
Date:
23 Jan 2007 11:30:51 -0800
Message-ID:
<1169580651.370563.170430@d71g2000cwa.googlegroups.com>
phillip.s.powell@gmail.com wrote:

Knute Johnson wrote:

phillip.s.powell@gmail.com wrote:

public static boolean isReachableURL(URL url)
    throws MalformedURLException, IOException, Exception {
        System.out.println("Testing to see if URL connects");
        HttpURLConnection conn =
(HttpURLConnection)url.openConnection();
        System.out.println("Created HttpURLConnection object");
        conn.connect();
        System.out.println("connecting..");
        boolean isConnected = (conn.getContentLength() > 0);
        System.out.println("disconnecting..");
        conn.disconnect();
        System.out.println("disconnected");
        return isConnected;
    }

I am trying to simply determine if a URL provided is a "reachable URL",
if so, return true, else, return false.

On most URLs I have no problem distinguishing reachable from
unreachable, but if you try something like this:

http://blah.com

It will lock up tight as a drum and I have to break into Windows Task
Manager to stop the process as it runs as an infinite loop at this
point.

So how can I reliably determine if a URL is reachable or unreachable?

Thanx
Phil


I don't know what the default timeout is on an HTTPURLConnection but it
will eventually time out. blah.com however does have a web server but
it is the slowest I have ever seen. It could be that you just need a
little patience.


I have no way of changing the default timeout in HttpURLConnection as
it has no property nor method that exists within the J2SE 1.4.2 API
that tells me how to set it. I was sitting there for a minute w/o any
results.


Got it! And it was so easy! No wonder nobody wanted to answer this one

/**
     * Determine if the given {@link java.net.URL} is reachable
     * @param url {@link java.net.URL}
     * @return {@link java.lang.Boolean}
     * @throws java.net.MalformedURLException To be thrown if the
{@link java.net.URL} is malformed
     * @throws java.io.IOException To be thrown if an I/O error occurs
     * @throws java.lang.Exception To be thrown if all other errors
occur
     */
    public static boolean isReachableURL(URL url)
    throws MalformedURLException, IOException, Exception {
        HttpURLConnection conn =
(HttpURLConnection)url.openConnection();
        conn.setConnectTimeout(10000); // SET CONNECTION TIMEOUT TO 10
SECS
        conn.setReadTimeout(10000); // SET I/O READ TIMEOUT TO 10
SECS
        // NO NEED TO USE connect() METHOD as getContentLength()
IMPLICITLY CONNECTS
        boolean isConnected = (conn.getContentLength() > 0);
        conn.disconnect();
        return isConnected;
    }

Phil

--

Knute Johnson
email s/nospam/knute/

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