Cannot instantiate component with component-type

[Kaustav Ganguly]

Hi,

I have defined some custom page tag and trying to use it in my application. I am running my server in eclipse and the component class is present in a jar file. While I try to load the page I am getting the exception "SEVERE: JSF1068: Cannot instantiate component with component-type page". Seems that it is not able to load the page component class present inside the jar file.

Interestingly when I extract the component classes and put them directly under the Web Application project in eclipse it works fine.

Please let me know if there is any pointer to the issue.

My web.xml has the following entry

<context-param>
<param-name>javax.faces.FACELETS_LIBRARIES</param-name>
<param-value>/WEB-INF/XYZ-taglib.xml</param-value>
</context-param>

Tag defination is

<tag>
<tag-name>page</tag-name>
<component>
<component-type>page</component-type>
</component>
<attribute>
<name>src</name>
<required>true</required>
</attribute>
<attribute>
<name>localName</name>
<required>false</required>
</attribute>
</tag>

And the tag component class is

package com.XYZ.neo.runtime.rendering.taglib;



import javax.faces.component.FacesComponent;
import javax.faces.component.UIComponentBase;
import javax.faces.context.ExternalContext;
import javax.faces.context.FacesContext;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * This class represents the page tag. 
 * <p>Declares which LiveSite page is being rendered. This prepares and renders
 *  the page but does not output the resulting HTML. Use one of the output tags 
 *  for that.</p> 
 *  <p>This tag must appear before the output tags.</p>
 * @author kgangu
 */
@FacesComponent(value = "page")
public class PageJSFTag extends UIComponentBase {
	
	/**
	 * Holds the src pattern of the site.
	 */
    protected static final Pattern SRC_PATTERN = Pattern.compile("sites/([^/]+)/(.+).page");
    
    /**
     * Holds the output key for a page.
     */
    protected static final String OUTPUT_KEY = PageTag.class.getName() + ".output";
	
	
	protected String mSrc;
	
	/**
	 * Holds the local name attribute of the page tag.
	 */
	protected String mLocalName = null;
	
	 protected static String getOutputKey(String localName)
	  {
	    if (localName == null)
	    {
	      return OUTPUT_KEY;
	    }

	    return OUTPUT_KEY + "[" + localName + "]";
	  }
	
	public String getSrc()
	{
	  return this.mSrc;
	}

	public void setSrc(String src)
	{
	  this.mSrc = src;
	}
	
	public String getLocalName()
	  {
	    return this.mLocalName;
	  }

	  public void setLocalName(String localName)
	  {
	    this.mLocalName = localName;
	  }

	  /**
	   * This method renders generates and renders the page.
	   */
	  @Override
	    public void encodeEnd(FacesContext context) throws IOException {
		  
		  //get the reuest and response from the Faces context
		  ExternalContext externalContext = context.getExternalContext();
	      ServletRequest servletRequest = (LiveSiteRequest)externalContext.getRequest();
	      ServletResponse servletResponse = (ServletResponse)externalContext.getResponse();
	      
	      // check if the src of the request matches the 
	      //expected src pattern for the tag.
	      Matcher m = SRC_PATTERN.matcher(this.mSrc);
	      
	      if (m.matches()) {
	    	  
	    	  //get the site name and the page name 
	    	  //used to create a output renderer
	        String siteName = m.group(1);
	        String pageName = m.group(2);

	        EmbeddedRenderer renderer = new EmbeddedRenderer((HttpServletRequest)servletRequest, (HttpServletResponse)servletResponse, "embedded.rendering.RenderingConfig");
	        RenderingOutput output = renderer.render(siteName, pageName);
	        servletRequest.setAttribute(getOutputKey(this.mLocalName), output);

	      }
	      
	      

	        
	    }

	@Override
	public String getFamily() {
		// TODO Auto-generated method stub
		return JSFTagConstants.FAMILY;
	}

}

The error stack trace is

SEVERE: JSF1068: Cannot instantiate component with component-type page
13:01:11,471 ERROR [XYZRenderingManager] render: handleException(RenderingException)
13:01:11,471 ERROR [XYZRenderingManager] Unhandled exception thrown during rendering

[Tom Fulton]

Well, by your description, it's acting like a classpath problem. How have you added the .jar to your project?

If you can extract the class and place it in the project, and it works, that means there isn't anything structurally wrong with the configuration. So I'd suggest trying a couple of different ways of making the .jar visible to both your project and the server (remember, the fact that the project can see it doesn't necessarily make it possible for the server to see it).

Good luck, and let us know what you find.

[Tim Holloway]

The fact that you're running Eclipse is tangental. To work properly, a webapp must be in WAR format, Eclipse or not, and that means that you must have a copy of the JAR in the WAR's WEB-INF/lib directory.

Eclipse normally doesn't automatically do that kind of stuff, which is why tools such as Ant and Maven are commonly used in webapp development. There are Eclipse plugins for both of these tools (Ant is built-in to the standard Java distro).