Upgrading to struts 2.3.15.1 does not set HashMap values on action class

Question

I upgraded from 2.1.6 to 2.3.15.1 because of the security fixes available in the latest version. However, now the form field values are not posted to the Action class. Basi

Answer 1

There have been huge changes since Struts 2.1.6. Struts 2 will not create objects for you if you don't explicitly tell it to do. The prepare method calls before the params interceptor sets props to the action, and you commented that you populate the map

//fill up props map here.

not surprisingly, that Struts not call that setter setProps because it already contains a map instance. So, it simply calls getProps. Then it should set the indexed property values to the map. But it doesn't know a type of the object that is an element of the collection to convert to, and if it should create a new object for element if it's null. By putting annotations on the props field it should solve the problem populating a map on submit.

@Element(value = Wall.class)
@CreateIfNull(value = true)
private Map props = new HashMap<>();

I guess the key it will determine automatically. The same could be done if you specify it in Action-conversion.properties

Element_props=Wall
CreateIfNull_props=true

Next your JSP could be replaced to

And last the Wall class you haven't posted, should look like

public class Wall {
  String value;
  //getter and setter here
}