package com.gregbugaj.jsfdump.console;
 
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
 
import javax.activation.MimetypesFileTypeMap;
import javax.faces.context.FacesContext;
import javax.faces.event.PhaseEvent;
import javax.faces.event.PhaseId;
import javax.faces.event.PhaseListener;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
 
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
 
import com.gregbugaj.jsfdump.util.JarUtil;
import com.gregbugaj.jsfdump.util.XMLUtil;
/**
 * Serve resources from jar file  back to the user by specifying resource name in resource-config.xml
 * 
 * This works with following syntax if faces servlet is *.jsf  /jsfdump/resource/script.js.jsf
 * or  /jsfdump/resource/script.js if faces servlet is *.*
 * 
 * @author devil
 *
 */
@SuppressWarnings("serial")
public class ResourcePhaseListener implements PhaseListener {
	//This is how the resource will be accessed ex /jsfdump/resource/script.js
	private static final String RESOURCE_PREFIX = "/jsfdump/resource/";
	//Location of where the js, img, css etc files reside inside the jar, we could also placed them in META-INF folder
	private static final String RESOURCE_PATH = "/com/gregbugaj/jsfdump/resources/";
 
	private static Map<String, String> resources=new HashMap<String,String>();
	private boolean isLoaded;
 
	@Override
	public void afterPhase(PhaseEvent event) {
		FacesContext facesContext=event.getFacesContext();
		String rootId=facesContext.getViewRoot().getViewId();
		//Clean up key
		String key=rootId.replace(RESOURCE_PREFIX, "");
		key=key.replace(".xhtml", "");
		key=key.replace(".jsf", "");
		if(!rootId.startsWith(RESOURCE_PREFIX)){
			return; 
		}
 
		//Lazy loading
		if(!isLoaded){
			isLoaded=initResources();
		}	
		String resourceName=resources.get(key);
		//Location of resources inside the jar file
		String fileName=RESOURCE_PATH+resourceName;
		InputStream resourceStream=JarUtil.getStreamFromJar(fileName);
		HttpServletResponse response = (HttpServletResponse) facesContext.getExternalContext().getResponse();
		response.setCharacterEncoding("UTF-8");
		ServletOutputStream sos = null;
		try {
			sos = response.getOutputStream();
			if(resourceStream!=null){
				response.setStatus(HttpServletResponse.SC_OK);
				//Resolve mime type, required that we have activation.jar loaded
				//Additional mime types can be defined in /META-INF/mimes.types  {@link http://java.sun.com/j2ee/sdk_1.3/techdocs/api/javax/activation/MimetypesFileTypeMap.html }
				String contentType = new MimetypesFileTypeMap().getContentType(fileName);
				response.setContentType(contentType);
				byte[] buffer= new byte[1024];
				for (int bytesRead = 0; (bytesRead = resourceStream.read(buffer, 0, buffer.length)) > 0;)
				{
					sos.write(buffer, 0, bytesRead);
				}
			}else{
				//Resource not found
				response.setStatus(HttpServletResponse.SC_NOT_FOUND);
				response.setContentType("text/html");
			}
			sos.flush();
			sos.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
		facesContext.responseComplete();
	}
 
	@Override
	public void beforePhase(PhaseEvent event) {
		//Do nothing
	}
 
	/**
	 * Load resource mapping from resource-config.xml
	 * @return true if we successfully loded resource
	 */
	private boolean initResources() {
		boolean retVal=true;
		InputStream stream=null;	
		try {
			stream=JarUtil.getStreamFromJar("/META-INF/resource-config.xml");
			Document document=XMLUtil.getXmlDocument(stream);
			NodeList resourceNodes=XMLUtil.extract("/resources/resource", document);
			for(int i=0;i<resourceNodes.getLength();i++){
				Node node=resourceNodes.item(i);
				String name=XMLUtil.attributeText(node, "name");
				String src=XMLUtil.attributeText(node, "src");
				//No forward slash in the resource name
				//ex js/scriptname.js not /js/script.js
				if(src.startsWith("/")){
					src=src.replaceFirst("/", "");
				}
				resources.put(name, src);
			}
		}  catch (IOException e) {
			retVal=false;
			e.printStackTrace();
		}
		catch (Exception e) {
			retVal=false;
			e.printStackTrace();
		}
		return retVal;
	}
 
	@Override
	public PhaseId getPhaseId() {
		return PhaseId.RESTORE_VIEW;
	}
}

  <?xml version="1.0" encoding="UTF-8"?>
  <resources>
	<resource name="proto.js" src="js/proto.js" />
	<resource name="logo.png" src="images/a.png" />
	<resource name="main.css" src="css/hello.css" />
  </resources>