Is for each on a map with EL possible?

[Jonny Andersson]

I am trying to learn the EL for the J2EE SCWCD-exam and have trouble when I try to loop over a map with a for each that use EL. Here is an example of what I try to accomplish, is it possible to do this?

I have a servlet that creates a map like this one:

Map movieList = new TreeMap();

It contains movie objects that has a name property like this:

public class Movie
{
    ...
 
    public String getName()
    {
        return name;
    }
    ...
 
}

And I the forward to a JSP page to print the list of movies using a for each like this:

<c:forEach var="movie" items="${movieList}">
  <p>
    ${movie.name}<br/>
  </p>
</c:forEach>

But it does not work. I get some error that say that a TreeMap$entry not have an attribute name ...

You can see what I try to do, is it possible or do you have a better, working, example?

And just to understand, is not

var="movie"

a reference to a movie objekt? One thing that complicates here is of course that I have a map. A map have keys and objects, am I iterating over the keys or the objects? With a list would I know that it is the objects, but I am not quite sure with a map. In normal Java would I have to iterate over the keys and then get the objects from the map using that keys.

[Christophe Verré]

Using the forEach loop for a Map will return an instance of Map.Entry for each iteration. If you look at the Map.Entry class, you'll see that it has a key and a value. So in your example, you should do the following :

<c:forEach var="movieEntry" items="${movieList}">
  <p>
    ${movieEntry.value.name}<br/>
  </p>
</c:forEach>

[Jonny Andersson]

That example from you looks so reasonable so that I already know that it must be correct ... I will try it later when I have time to look at it again. A lot of thanks for your help!