Interfacing with RESTful web services

Question

The following working function seems a bit hacky to me as it has been pieced together from a handful of (probably poorly written) online tutorials, and I want to know if there is a better (or more standard) way to approach this.

/***
 * GET HTTP Operation
 * 
 * @param   request Request URI 
 * @return  Element Root Element of XML Response
 */
protected Element get(String request) {

    HttpURLConnection connection = null;

    Element rootElement;

    try {

        URL url = new URL(this.baseUrl + request);
        connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("GET");
        BASE64Encoder enc = new sun.misc.BASE64Encoder();
        String userpassword = this.username + ":" + this.password;
        String encodedAuthorization = enc.encode( userpassword.getBytes() );
        connection.setRequestProperty("Authorization", "Basic "+ encodedAuthorization);
        connection.setRequestProperty("Content-type", "application/xml");
        connection.setRequestProperty("Accept", "application/xml");

        InputStream responseStream = connection.getInputStream();

        //--- Parse XML response InputStream into DOM

        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        DocumentBuilder db = dbf.newDocumentBuilder();

        Document doc = db.parse(responseStream);

        rootElement = doc.getDocumentElement();

    } catch(Exception e) {

        System.out.print(e.toString());
        rootElement = null;

    } finally {

        if(connection != null) {
            connection.disconnect(); 
        }

    }

    return rootElement;
}

I am a Java novice and am especially unclear on proper try/catch usage.

I am creating a Java Wrapper for an REST API and this is a small piece of that puzzle. You can click here to see a bigger picture of the project as a whole.

Answer 1

Adding another answer since I'm actually looking at the code now...

You are swallowing every exception that gets thrown. The calling code has no idea whether it tried to hit a page that didn't exist, its request was malformed, etc. If you don't want to expose the exceptions (probably a good idea so your client code doesn't have to worry), then you might want to set some sort of error flag as part of your class that can be probed for the cause of not getting back the XML, or throw your own custom exceptions.

I'm assuming in your other methods you do similar sorts of set up for the connection (the accepts, etc)...I'd recommend moving that out into its own setup method. If you need to specialize based on the type of request, then pass in the type and you can at least consolidate all of that into one place.