Example: Accessing a service using Java

For this to work, you'll need to download and include a few *.jar files for ApacheXmlRpc.

1. From http://www.apache.org/dyn/closer.cgi/ws/xmlrpc/ download the appropriate "apache-xmlrpc-current-bin.*" file.
2. Extract the files to a location that can be used to import them for NetBeans in you project.
3. Add them to your projects Libraries.

To use it, you will need to know the sites Service Key, Service Domain, and the Service URL. Below is a sample of how you use the class

Here's how you would use the class

	public static void main(String[] args) throws Exception {
		DrupalXmlRpcService service = new DrupalXmlRpcService(
                "aperture",
                "442c5629267cc4568ad43ceaa7f3dbe4",
                "http://localhost/organikdrupal/?q=services/xmlrpc");
        service.connect();
        service.login("root", "root");
    	DrupalNode node = new DrupalNode();
    	node.setType(DrupalNode.TYPE_STORY);
    	node.setTitle("HEllo WORLD");
    	node.setBody("at "+new Date().toGMTString());
        service.nodeSave(node);
        service.logout();
        System.out.println("done");

	}

Sample Class

package org.semanticdesktop.aperture.drupalhandler;
import java.net.MalformedURLException;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.Map;
import java.util.Vector;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import org.apache.xmlrpc.client.XmlRpcClient;
import org.apache.xmlrpc.client.XmlRpcClientConfigImpl;

/**
 * XML-RPC client for the server offered by Drupal.
 * Drupal has a weird authentication scheme on the server side involving to sign every method
 * call using a HMAC signature generated with SHA256 hashing and the API key of Drupal as 
 * key. This class implements this authentication scheme and some method calls based on the 
 * apache XML-RPC implementation.
 * 
 * Usage:
 <pre>
 DrupalXmlRpcService service = new DrupalXmlRpcService("domain", "442c5629267cc4568ad43ceaa7f3dbe4", "http://www.example.com/drupal/?q=services/xmlrpc");
 service.connect();
 service.login(user, password);
 service.nodeSave(mynode);
 service.logout();
 </pre>
 * 
 * see http://drupal.org/node/632844, with adaptations by Leo Sauermann
 * 
 * Changelog 16.2.2010 - made exceptions where exceptions are due, changed logging to JUL
 * 
 * This class is written by Leo Sauermann on the basis of work published by Aaron Moline.
 * 
 * It is currently part of the Aperture sourceforge project which is BSD licensed,
 * if you want to put it elsewhere, do so under this license.
 * 
 * @author Aaron Moline <Aaron.Moline@molinesoftware.com>
 * @author Leo Sauermann <leo.sauermann@dfki.de>
 */
public class DrupalXmlRpcService {
	
	/**
	 * Method names
	 * @author sauermann
	 */
	public static final String MethodNodeSave = "node.save";
	public static final String MethodSystemConnect = "system.connect";
	public static final String MethodUserLogout = "user.logout";
	public static final String MethodUserLogin = "user.login";
	public static final String MethodFileSave = "file.save";
	public static final String MethodTestCount = "test.count";

	Logger log = Logger.getLogger(DrupalXmlRpcService.class.getName());

	final String serviceURL;
	final String serviceDomain;
	final String apiKey;
	/**
	 * SessionID is set by "connect"
	 */
	String sessionID;
	XmlRpcClient xmlRpcClient;

	/**
	 * needed for signing
	 */
	final Charset asciiCs = Charset.forName("US-ASCII");
	
	/**
	 * Message authentification code algorithm already initialized with the ApiKey.
	 */
	Mac apikeyMac;

	/**
	 * Initialize the Drupal XML-RPC Service.
	 * The serviceURL must be a valid URL.
	 * @param serviceDomain domain
	 * @param apiKey the API key with the domain
	 * @param serviceURL the URL of the Drupal service. example: http://www.example.com/drupal/?q=services/xmlrpc
	 * @throws MalformedURLException if the serviceURL is not a URL
	 */
	public DrupalXmlRpcService(String serviceDomain, String apiKey,
			String serviceURL) throws MalformedURLException {
		this.serviceDomain = serviceDomain;
		this.apiKey = apiKey;
		this.serviceURL = serviceURL;
		
		// initialize the xmlRpcClient, it won't change as the parameters are final
		XmlRpcClientConfigImpl config = new XmlRpcClientConfigImpl();
		config.setServerURL(new URL(this.serviceURL));
		xmlRpcClient = new XmlRpcClient();
		xmlRpcClient.setConfig(config);
	}


	/**
	 * generate a random string for signing methods
	 * @return
	 */
	private String generateNonce(){
		/*
		 * //TODO:Get None Generator Working String allowedCharacters =
		 * "abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ23456789";
		 * StringBuilder password = new StringBuilder();
		 * Random rand = new Random(); for (int i = 0; i < length; i++) {
		 * password.append() //password.append(append); }
		 * return password.toString();
		 */
		return "" + System.currentTimeMillis();
	}

	/**
	 * Generate the default parameters that need to precede every call
	 * @param methodname pass in the method name which should be signed.
	 * @return the default parameters. The Vector can be reused to pass other objects via XML-RPC, 
	 * hence the resulting vector is typed to "Object" rather than String.
	 */
	private Vector<Object> generateDefaultParams(String methodname) throws Exception {
		String nonce = generateNonce();
		long timestamp = System.currentTimeMillis();
		// Build String for hashing. As this is one line, no StringBuilder is used.
		String hashString = Long.toString(timestamp) + ";" + serviceDomain + ";" + nonce + ";" + methodname;
		String hash = generateHmacHash(hashString);
		
		Vector<Object>  params = new Vector<Object>();
		
		params.add(hash);
		params.add(this.serviceDomain);
		params.add(Long.toString(timestamp));
		params.add(nonce);
		params.add(this.sessionID);
		return params;
	}

	/**
	 * Compute the HMAC-SHA256 hash of the passed message.
	 * As key, the API key is used.
	 * @param message the message to hash
	 * @return the hash as hex-encoded string.
	 * @throws Exception if the encoding algorithm HmacSHA256 can't be found or other problems arise.
	 */
	public String generateHmacHash(String message) throws Exception {
		byte[] hash = getApikeyMac().doFinal(asciiCs.encode(message).array());
		
		String result = "";
		for (int i = 0; i < hash.length; i++) {
			// Leo: I don't understand why Aaron put this here. If its overcomplex, please simplify. I don't care for now.
			result += Integer.toString((hash[i] & 0xff) + 0x100, 16)
					.substring(1);
		}
		log.finest("Created HMAC: " + result+ " of "+message);
		return result;
	}
	
	/**
	 * Getter for HMAC, as this is used on every call, its good to buffer it.
	 * As the ApiKey is final, this can be buffered.
	 * @return
	 */
	private Mac getApikeyMac() throws Exception {
		if (apikeyMac==null)
		{
			SecretKeySpec keySpec = new javax.crypto.spec.SecretKeySpec(asciiCs
					.encode(this.apiKey).array(), "HmacSHA256");
			apikeyMac = javax.crypto.Mac.getInstance("HmacSHA256");
			apikeyMac.init(keySpec);
		}
		return apikeyMac;
	}
	
	/**
	 * Connect to the remote service
	 * 
	 * @return
	 * @throws Exception
	 */
	public void connect() throws Exception {
		try {
			Map map = (Map) xmlRpcClient
					.execute(MethodSystemConnect,
							new Object[] {});
			this.sessionID = (String) map.get("sessid");
			log.fine("Connected to server using SessionID: " + this.sessionID);
		} catch (Exception x) {
			throw new Exception("cannot connect to "+serviceURL+": "+x.getMessage(),x);
		}
	}

	/**
	 * Call user.login
	 * @return
	 */
	public void login(String username, String password) throws Exception {
		Vector<Object> params = generateDefaultParams(MethodUserLogin);
		// Add Login Paramaters
		params.add(username);
		params.add(password);

		Map o = (Map) xmlRpcClient.execute(
				MethodUserLogin, params);
		// IMPORTANT: the login changes the session id! The new session ID is authorized, the old one not.
		this.sessionID = (String) o.get("sessid");

		log.fine("Successfull Login");
	}

	/**
	 * Call user.logout
	 */
	public void logout() throws Exception {
		Vector<Object> params = generateDefaultParams(MethodUserLogout);
		params.add(this.sessionID);
		xmlRpcClient.execute(MethodUserLogout, params);
		log.finer("Logout Sucessfull");
	}

	/**
	 * Call file.save.
	 * Pass in the file as byte-array.
	 * TODO: Leo says: This does not conform to the Drupal interface of file.save - its a leftover from Aaron's code.
	 */
	public void fileSave(byte[] file) throws Exception {
		Vector<Object> params = generateDefaultParams(MethodFileSave);
		params.add(file);
		Object o = xmlRpcClient.execute(MethodFileSave, params);
		if (log.isLoggable(Level.FINEST))
			log.finest(MethodFileSave+" returned "+o.toString());
	}

	/**
	 * Call node.save
	 * @param node the node to save
	 */
	public void nodeSave(DrupalNode node) throws Exception {
		Vector<Object> params = generateDefaultParams(MethodNodeSave);
		params.add(node);
		Object o = xmlRpcClient.execute(MethodNodeSave, params);
		if (log.isLoggable(Level.FINEST))
			log.finest(MethodNodeSave+" returned "+o.toString());
	}
}

/**
 * 
 */
package org.semanticdesktop.aperture.drupalhandler;

import java.util.HashMap;
import java.util.Map;

/**
 * A drupal Node.
 * It sets and gets all its variables as MAP entries.
 * @author sauermann
 *
 */
public class DrupalNode extends HashMap<String, Object> {
	
	/**
	 * types
	 */
	public static final String TYPE_STORY = "story";
	
	public static String NID = "nid";
	public static String TYPE = "type";
	public static String LANGUAGE = "language";
	public static String UID = "uid";
	public static String STATUS = "status";
	public static String CREATED = "created";
	public static String CHANGED = "changed";
	public static String TITLE = "title";
	public static String BODY = "body";
/*	more for future
 * public static String NID = "comment";
	public static String NID = "promote";
	public static String NID = "moderate";
	public static String NID = "sticky";
	public static String NID = "tnid";
	public static String NID = "translate";
	public static String NID = "vid";
	public static String NID = "revision_uid";
	public static String NID = "teaser";
	public static String NID = "log";
	public static String NID = "revision_timestamp";
	public static String NID = "format";
	public static String NID = "name";
	public static String NID = "picture";
	public static String NID = "data";
	public static String NID = "rdf";
	public static String NID = "last_comment_timestamp";
	public static String NID = "last_comment_name";
	public static String NID = "comment_count";
	public static String NID = "taxonomy";
	public static String NID = "build_mode";
	public static String NID = "readmore";
	public static String NID = "content";
	*/

	public DrupalNode() {
		super();
	}

	public DrupalNode(int initialCapacity, float loadFactor) {
		super(initialCapacity, loadFactor);
	}

	public DrupalNode(int initialCapacity) {
		super(initialCapacity);
	}

	public DrupalNode(Map m) {
		super(m);
	}
	
	public long getNid() {
		Object nid = get(NID);
		if (nid == null)
			throw new RuntimeException("nid not set (null)");
		if (nid instanceof String) {
			long result = Long.parseLong((String)nid);
			put(NID, result); // replace, for future
			return result;
		} else
			return (Long)nid;
	}
	
	public void setNid(long nid) {
		put(NID, nid);
	}
	
	public String getTitle() {
		Object o = get(TITLE);
		if (o==null)
			return null;
		else
			return o.toString();
	}
	
	public void setTitle(String o) {
		put(TITLE, o);
	}
	
	public String getBody() {
		Object o = get(BODY);
		if (o==null)
			return null;
		else
			return o.toString();
	}
	
	public void setBody(String o) {
		put(BODY, o);
	}

	public void setType(String o) {
		put(TYPE, o);
	}
}

For more information: https://aperture.svn.sourceforge.net/svnroot/aperture/aperture-webserver...