JSTL - Using forEach to iterate over a user-defined class [duplicate]

Answer 1

Unfortunately, the forEach tag does not support Iterable as the items source. It does support:

• Arrays
• Collection
• Iterator
• Enumeration
• Map
• Comma-separated list of values given in a String

(relevant source code: ForEachSupport)

Of these, it's probably best to use an Iterator as the forEach source when you wish to fetch items from your own class.

Answer 2

Yes, you should implement java.util.Iterable

Answer 3

The Iterable interface provides this functionality:

public class ProjectSet implements Iterable<Project> {
    private ArrayList<Project> projects;
    public ProjectSet() {
        this.projects = new ArrayList<Project>();
    }

    // .. iteration methods ??
   @Override
   public Iterator<Project> iterator() {
       return projects.iterator();
   }
}

You can exchange the iterator logic as you need.