How to insert a value into Set collection in Struts 2

问题

I am doing a project using Struts2 and I have a problem assigning a set collection.

Here's my Action (I eliminated the irrelevant part)

public class TeamAction extends BaseAction implements ModelDriven<Team>
{
 Team team=new Team();

}

Here's my model Team (I eliminated the irrelevant part)

private TeamId id;
private Set students = new HashSet(0);

Here's my JSP part

<input type="text" name=team.student[0].id />

Now the problem is I can't insert the right value into this Set collection in by ModelDriven, it will throw a exception. Could you please tell me what to write in JSP file, so I can insert a value to Set collection in my model?

回答1:

Set is a Collection and as any other collection could be indexed by a property.

@Element(value = Student.class)
@Key(value = Integer.class)
@KeyProperty(value = "id") 
@CreateIfNull(value = true)
private Set<Student> students = new HashSet(0);
//getter and setter, also for Student class that should have Integer id.

in JSP

<s:iterator value="students " var="student">
  <s:textfield name="students(%{#student.id}).name" />
</s:iterator>

More about this see in Indexing a collection by a property of that collection.

来源：https://stackoverflow.com/questions/24186111/how-to-insert-a-value-into-set-collection-in-struts-2