Java Beans

1
Java Beans

• a reusable software component that can be
  manipulated visually in a builder tool
• AWT components are all beans
• an embeddable spreadsheet application might be a
  bean
• most beans are somewhere in between

2
Java Beans

• any object that conforms to a few basic rules can
  be a bean
• interoperability with similar components is
  required
• a bean exports properties, events and methods

3
beans

• a property is a piece of the beans internal state
  that may be programmatically set and queried,
  usually with set and get methods
• a bean may generate an event like a Button
  generates an Action Event
• it uses the same model as java 1.1
• provides methods for adding and removing listener
  objects

4
beans

• an exported method is any public method of the
  bean other than those mentioned above
• a bean should define a constructor that expects
  no arguments
• visual studio from Sun is a builder tool that
  demonstrates how beans are used