src/main/java/org/jboss/util/property/PropertyMap.java
public Object put(Object name, Object value)
   {
      if (name == null)
         throw new NullArgumentException("name");
      // value can be null

      // check if this is a new addition or not prior to updating the hash
      boolean add = !containsKey(name);
      Object prev = super.put(name, value);

      PropertyEvent event =
         new PropertyEvent(this, name.toString(), value.toString());

      // fire propertyAdded or propertyChanged
      if (add)
      {
         firePropertyAdded(event);
      }
      else
      {
         firePropertyChanged(event);
      }

      return prev;
   }
public Object put(Object name, Object value)
   {
      if (name == null)
         throw new NullArgumentException("name");
      // value can be null

      // check if this is a new addition or not prior to updating the hash
      boolean add = !containsKey(name);
      Object prev = super.put(name, value);

      PropertyEvent event =
         new PropertyEvent(this, name.toString(), value.toString());

      // fire propertyAdded or propertyChanged
      if (add)
      {
         firePropertyAdded(event);
      }
      else
      {
         firePropertyChanged(event);
      }

      return prev;
   }
Set a property.

@param name    Property name.
@param value   Property value.
@return        Previous property value or null.