Dr. Chuck's Web Log

Calling REST Web Services from Java

Wow - it initially seemed much harder to do REST web services in Java than it should have been - it took a while for me to find this web site. Everyone wanted me to download a jar or something - I knew this had to work in a few lines of Java with no jars...

Thanks to: http://xml.nig.ac.jp/tutorial/rest/index.html

My code below.

try {
    // Thanks: http://xml.nig.ac.jp/tutorial/rest/index.html
    URL url = new URL(restEndPoint);

    //make connection, use post mode, and send query
    URLConnection urlc = url.openConnection();
    urlc.setDoOutput(true);
    urlc.setAllowUserInteraction(false);
    String encodedPost = URLEncoder.encode(ret);
    PrintStream ps = new PrintStream(urlc.getOutputStream());
    ps.print("launchData="+encodedPost);
    ps.close();

    //retrieve result
    BufferedReader br = new BufferedReader(new InputStreamReader(urlc
                .getInputStream()));
    String str;
    StringBuffer sb = new StringBuffer();
    while ((str = br.readLine()) != null) {
            sb.append(str);
            sb.append("\n");
    }
    br.close();
    response = sb.toString();

    if ( response == null ) { 
        setErrorMessage(request, "Launch REST Web Service returned nothing");
    }
}
catch(Exception e) {
        e.printStackTrace();
        setErrorMessage(request, "Failed REST service call. Exception="+e);
        response = null;
}

Posted by csev at September 9, 2007 08:17 AM