JavaBeans
In computing based on the Java Platform, JavaBeans are classes that encapsulate many objects into a single object (the bean). They are serializable, have a zero-argument constructor, and allow access to properties using getter and setter methods. The name "Bean" was given to encompass this standard, which aims to create reusable software components for Java.
Advantages
The properties, events, and methods of a bean that are exposed to another application can be controlled.
A bean may register to receive events from other objects and can generate events that are sent to those other objects.
Auxiliary software can be provided to help configure a java bean.
The configuration settings of a bean can be saved to persistent storage and restored.
Disadvantages
A class with a nullary constructor is subject to being instantiated in an invalid state. If such a class is instantiated manually by a developer (rather than automatically by some kind of framework), the developer might not realize that the class has been improperly instantiated. The compiler cannot detect such a problem, and even if it is documented, there is no guarantee that the developer will see the documentation.
