Java - Interact with website to update information

Question

So I got this situation and I may have 2 different routes to take. The thing is I have to update some information I generate, already formatted and parsed and ready to be displayed. Now I don't know how to input this txt file (or giant string) into the site. One way to do it is to find a way for Java to interact with the page, paste the info in the text area and Save/Submit the update. The other way is to edit the page file itself inserting the giant string in the place it's supposed to go. I've been researching about HTTP Forms, but most are used with third party libraries. But I have no idea how to do either route. Ive been checking these sites, and other, but I think some are too complex or need external libraries like Selenium, and I really have no experience using URLConnection class. Thanks for the help!

--I don't have control of the server, I can simply access it, so I was thinking that the first idea would be more practical...

http://kspace.in/blog/2008/05/30/submit-html-form-using-java/

http://www.devcomments.com/q450155/How-to-have-Java-application-interact-with-website

Answer 1

Use HTTP Post:

http://www.exampledepot.com/egs/java.net/post.html

try {
    // Construct data
    String data = URLEncoder.encode("key1", "UTF-8") + "=" + URLEncoder.encode("value1", "UTF-8");
    data += "&" + URLEncoder.encode("key2", "UTF-8") + "=" + URLEncoder.encode("value2", "UTF-8");

    // Send data
    URL url = new URL("http://hostname:80/cgi");
    URLConnection conn = url.openConnection();
    conn.setDoOutput(true);
    OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
    wr.write(data);
    wr.flush();

    // Get the response
    BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
    String line;
    while ((line = rd.readLine()) != null) {
        // Process line...
    }
    wr.close();
    rd.close();
} catch (Exception e) {
}

Answer 2

Your best bet is to use a framework designed for automated testing, such as Selenium/WebDriver or HtmlUnit. Yes, you're not actually running tests, but they work well for this kind of automation.