Constructing the model

The Folder Listing web script constructs a HashMap and places the verbose flag and located folder into it:

...
  Map<String, Object> model = new HashMap<String, Object>();
  model.put("verbose", verbose);
  model.put("folder", folder);
  return model;
...

      

The model is then subsequently available to response templates, which can use the values to render the output. Values placed into the map by Java are converted to values that the FreeMarker template language can access. For example, your Java Folder Listing web script places a NodeRef into the model under the name folder, which it received from the Repository service. A NodeRef represents a reference to an object residing in the content repository. The Web Script Framework converts NodeRefs into full objects so that FreeMarker templates can easily reference their object properties and methods as demonstrated by your Folder Listing response template:

Contents of folder ${folder.displayPath}/${folder.name}

A Java-backed web script does not have to create a model. In this case, the executeImpl() method can return null.