Struts 2 ActionMapper Implementation

In the topics application I wanted to be able to map URLs like:

http://www.arevalos.org/topics/twitter/opencode.html

http://www.arevalos.org/topics/twitter/t_ajax.html

I wanted to map those URLs to the same struts 2 action and use the same view, since the view can be re-utilized for all the different accounts. After an initial research on the Struts 2 Guides, I thought I might be able to utilize the “Parameters in namespaces”, but they rely on the deprecated (version as of this writing 2.1.6) Codebehind Plugin, and I didn’t really want to use deprecated stuff.

So I continued looking through the documentation, Google did not help me much, maybe I was not searching right. Anyway what I found was that maybe an implementation of an Action Mapper.

For my application, where the root context is /topics I came up with the following code:

/**
 *
 */
package org.arevalos.topics.struts2.dispatcher.mapper;

import java.util.ArrayList;
import java.util.Map;
import java.util.TreeMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.dispatcher.mapper.ActionMapping;
import org.apache.struts2.dispatcher.mapper.DefaultActionMapper;

import com.opensymphony.xwork2.config.ConfigurationManager;

/**
 * @author Cesar Arevalo
 * @since 0.0.1
 */
public class TwitterActionMapper extends DefaultActionMapper {

	public TwitterActionMapper() {
		super();
		extensions = new ArrayList();
		extensions.add("html");
		extensions.add("");
	}

	private static String getAccountFromUrl(String s, String regex) {
		Matcher m = Pattern.compile(regex).matcher(s);
		return m.find() ? m.group(1) : null;
	}

	@Override
	public ActionMapping getMapping(HttpServletRequest request,
			ConfigurationManager configManager) {
		String uri = getUri(request);
		String regex = "/twitter/(\\w+).html";
		String id = getAccountFromUrl(uri, regex);
		if (id != null) {
			ActionMapping m = new ActionMapping();
			m.setExtension("");
			m.setMethod("execute");
			m.setNamespace("/twitter");
			m.setName("account");
			Map params = new TreeMap();
			params.put("twitterAccount", id);
			m.setParams(params);
			return m;
		}
		return super.getMapping(request, configManager);
	}
}

There are probably some more optimizations I can apply to the code, but right now it works!

http://www.arevalos.org/topics/twitter/opencode.html