What is Java Bean: A JavaBean is a reusable software component that follows certain conventions and guidelines defined by the JavaBean API. JavaBeans are used to encapsulate and package together data (properties) and functionality (methods) into a single unit, making it easy to manage and manipulate these components within applications.
JavaBeans have properties, which are accessed through getter and setter methods. The four categories of bean properties are:
These are basic properties that have a single value, such as primitive data types or simple objects. They have a single getter method to retrieve the value and a single setter method to set the value.
These properties are collections or arrays of values, and each value is indexed. Indexed properties have methods to get and set values at specific indices within the collection. The getter method for indexed properties takes an index parameter, while the setter method takes both an index and a value.
Bound properties are properties that can generate events when their values change. This allows other parts of the application to listen for changes in these properties. They involve adding listeners and notifying them when the property value changes.
Constrained properties are similar to bound properties, but they provide additional control over whether a property change is allowed. Before a constrained property’s value is changed, a vetoable change event is fired, giving listeners the chance to veto the change if necessary.
What is Java Bean In summary, JavaBeans are reusable components that follow specific conventions for property access and manipulation. The four categories of bean properties (simple, indexed, bound, and constrained) define different ways in which properties can be used, accessed, and interacted with in JavaBeans.