Setting bean in Simple tag attribute

[Harshvardhan gupta]

According to HFSJ i am trying example on page 521.
I tried the following but my jsp shows nothing. it comes out blank.Please help dear intellects


JSP that uses tag :

<%@ page import="java.util.*" %>
<%@ page import="com.example.model.*" %>
<%@ taglib prefix="myTags" uri="simpleTags" %>

<%	
	List<Movie> movieCollection= new ArrayList<Movie>();
	
	Movie m1=new Movie("The Hangover"); 
	Movie m2=new Movie("American Physco"); 
	Movie m3=new Movie("The Expendables");
	
		 
	
	movieCollection.add(m1);   
	movieCollection.add(m2);
	movieCollection.add(m3);
	
		
%>


<table>
 
 <myTags:simple2 movieList="${movieCollection}">
 <tr>
 
 <td>${movie.name}</td>
 
 </tr>
 </ myTags:simple2 >
 </table>

the tag handler:

package com.example.web;
import javax.servlet.jsp.tagext.SimpleTagSupport;
import java.io.*;
import javax.servlet.jsp.*;
import java.util.*;
import com.example.model.*;

public class SimpleMovieMaker extends SimpleTagSupport
{

	 
	
	private List movieList;
	
	public void setMovieList(List movieList)
	{
		this.movieList=movieList;
	}
	
	public void doTag() throws JspException,IOException
	{
		Iterator it =movieList.iterator();
		while(it.hasNext() )
		{
			Movie movie=(Movie) it.next();
			
			
			getJspContext().setAttribute("movie",movie);
			getJspBody().invoke(null);
			
		}
	}
	
}

the object to be set as attribute:

package com.example.model;

public class Movie 
{
	public String name;
	

	public  Movie(String name)
	{
	
		this.name=name;
		
		
	}
	
	

}

TLD file for tag :

<?xml version="1.0" encoding="UTF-8" ?>

<taglib xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
    version="2.0">
	
	<tlib-version>1.2</tlib-version>
	<uri>simpleTags</uri>


<tag>
		<description> Now showing movies </description>
		<name>simple2</name>
		<tag-class>com.example.web.SimpleMovieMaker</tag-class>
		<body-content>scriptless</body-content>
		<attribute>
			<name>movieList</name>
			<required>true</required>
			<rtexprvalue>true</rtexprvalue>
		</attribute>
	</tag>

[Stefan Evans]

You are mixing up Scriptlet variables with EL variables.
These things are not the same.

${movieCollection} does not refer to your scriptlet variable movieCollection, but is rather looking for an attribute of that name.
ie the java equivalent of ${movieCollection} would be pageContext.findAttribute("movieCollection");

One solution (for this example page)
add this to the end of your <% scriptlet %> section where you define the list of movies:

pageContext.setAttribute("movieCollection", movieCollection);

This puts the movieCollection variable into the page attribute space where your EL reference can then find it.

[Bear Bibeault]

Although, using scriptlets at all in your JSP pages is not recommended.

And mixing scriptlets with JSTL and EL is even less recommended,

If you are going to use scriptlets (not recommended) then just use scriptlets. Mixing scriptlets with JSTL/EL is just a big old mess.

[Harshvardhan gupta]

Do I also need to specify the type for attribute movieList as java.util.List in the TLD file?

[Tex Martin]

Hi Harshvardhan
I'm on the same page in HFSJ :-)
Apart from what can be learned from the other answers, it caught my eye that your javaBean lacks getter/setter for the name attribute.

I just tried it out on Jetty; it says "The class 'foo.Movie' does not have the property 'name'". I don't know if e.g. TomCat are more lenient.

Cheers and good luck

Tex Martin

[Harshvardhan gupta]

you are absolutely correct my friend . Actually initially when i started trying it my intentions were to make it a bean . But i just ended up with trying a normal object which could be set in tag attribute . so it cant be called a bean without getter and setter but atleast i needed to check whether any random object can be set in attribute value . thanks and regards