Prepared by :- Hitesh Parmar

hitesh.parmar915@gmail.com

@i_hiteshparmar

What is a Java Bean.What is a Java Bean.Components and classes with respect to Java Components and classes with respect to Java

Bean.Bean.Java.Beans(Package).Java.Beans(Package).The Component and its type in Java Beans.The Component and its type in Java Beans.Useful Terms while Using Java Beans.Useful Terms while Using Java Beans.Software ComponentsSoftware ComponentsVisually Manipulated, Builder ToolsVisually Manipulated, Builder ToolsSupportSupport

“It’s a Component Architecture of Java which allow you to define the Component ”

Java Bean is nothing but the Java Class.

Example:-Swing are all the Java Bean component Component (Button,TextField,Label)

Java Bean classes follow certain Rule or Condition.

All java Bean classes must Implement the Serializable Interface.

Component may be used by some apllication builder.

A bean has a no argument constructor.

Serializing

CLASS

Class Object

Component Object

Java Bean API makes it possible to write the component s/w in a java programming language.

This package will be used depending upon the need of the Application (based on funcion of bean classes).

Now when its only the use of the property or the Getter & Setter Method at that time you might not even make a use of this package.

The component is nothing but the group of classes.

Example:- Jbutton(it’s a component not a class).In order to a swing Button there are whole lot of

class are involved to build this Jbutton.Component is a single Functionality provided

by many different classesComponent is a group of classses that interact

with eachother to fulfill the single purpose.

Application developer uses different beans in his application using the Java Beans.

You can build two types of Components.

Component

GUI based

Non GUI based

Extends Component

PropertiesEventPersistenceIntrospectionCustomization

Discrete, Discrete, named attributes named attributes that that determinedetermine the the appearanceappearance , ,behaviorbehavior and and statestate of a of a component.component.

Accessible programmatically through Accessible programmatically through accessoraccessor methods. methods.

Accessible visually through Accessible visually through property sheets.property sheets.

Simple PropertiesSimple Properties

Boolean PropertiesBoolean Properties

Indexed PropertiesProperties

1 Simple Properties:-1 Simple Properties:-Represent a single value.Represent a single value.The accessor methods should follow standard The accessor methods should follow standard

naming conventions.naming conventions.

public <PropertyType> get<PropertyName>();public void set<PropertyName>(<PropertyType> value);

Example:

public String getHostName();public void setHostName( String hostName );

2 2 BooleanPropertiesBooleanProperties:-:-They are simple propertiesThey are simple propertiesThe getter methods follow an optional design The getter methods follow an optional design

patternpattern

public boolean is<PropertyName>();

Example:

public boolean isConnected();

3 3 Indexed PropertiesProperties:-:-Represent an array of valuesRepresent an array of values

public <PropertyElement> get<PropertyName>(int index);public void set<PropertyName>(int index,<PropertyElement> value);public <PropertyElement>[] get<PropertyName>();public void set<PropertyName>(<PropertyElement>[] values);

Example:public Color setPalette(int index);public void setPalette(int index,Color value);public Color[] getPalette();public void setPalette(Color[] values);

Bound:-a bound property notifies other objects when its

value changesgenerates a PropertyChange event with property

name, old value and new value

Constrained:-an object with constrained properties allows

other objects to veto a constrained property value change

Constrained property listeners can veto a change by throwing a PropertyVetoException

Two types of objects are involved:Two types of objects are involved:““Source” objects.Source” objects.““Listener” objects.Listener” objects.

Message sent from one object to another.Message sent from one object to another.

Sender Sender firesfires event, recipient (listener) event, recipient (listener) handleshandles the event the event

There may be many listeners.There may be many listeners.

Eventsource

Eventlistener

Fire eventEvent Object

Register listener

Sender fires event, recipient (listener) handles the event

PersistanceYour Bean should be able to store its state, which

means there should be the serializable interface.

Upon the Bean a builder tool should be able to make a reflaction and be able to create an object of your component.

[Ex. Drag and drop a component in to a design area and the builder tool should be able to create the instance of that component and be able to display the property of that bean via reflaction.]

Customization Using the Bean customization, you can specify

what methods or the properties that you want to expose at rhe run time environment, so such property will be displayed in the propertysheet.

IntrospectionIs nothing but a reflection using which the

builder tool can display all the events and the properties of the component.

Reflection APIIt helps us to find out what are the contents of

the class, so you can findout what are the methods, constructors and variables in the class and you can find out the details in return.

Due to the process of the reflection builder tool can be able to display what are the property of the Component in the property sheet and also provides the details regarding the Events and methods.

ButtonsText FieldsList BoxesScroll BarsDialogs

BeanBoxToolBoxToolBox BeanBoxProperty Sheet

BDK - SunBDK - SunNetBeans – www.netbeans.orgNetBeans – www.netbeans.orgJbuilder - InpriseJbuilder - InpriseSuper Mojo - Penumbra SoftwareSuper Mojo - Penumbra SoftwareVisual Age for Java - IBMVisual Age for Java - IBMVisual Cafe - Symantec CorporationVisual Cafe - Symantec CorporationJDeveloper Suite - OracleJDeveloper Suite - Oracle