What is java beans with example for beginners 2022

What is javaBeans ?

Java beans are classes that combine multiple objects into one. They have a zero parameter function Object() { [native code] }, are serializable, and support getter and setter methods for accessing properties.

An object class must adhere to specific guidelines about method naming in order to function as a javaBean class. behaviour, construction, and. The existence of tools that can use, resolve, replace, and connect JavaBeans is made feasible by these conventions.

The following are the required conventions:

There must be a public default function Object() { [native code] } for the class. Because of this, the editing and activation framework can easily instantiate objects.

According to a common naming convention, the class properties must be reachable using the get set, is, and other methods (also known as accessor methods and mutator methods). This enables simple automatic bean state examination and modification within frameworks, many of which have specialised editors for different kinds of properties. Setters may contain one or more arguments.

The class ought to support serialisation. This makes it possible for programmes and frameworks to consistently save, preserve, and restore a bean's state in a way that is independent of the virtual machine and the platform.

According to the javaBeans definition, a bean is a reusable software element that may be visibly modified via a building tool. To put it another way, the Javabeans API is particular to a software component paradigm where the components are referred to as beans.

• A bean can contain any Java code, regardless of complexity. A basic example of a bean is any of the Java AWt components, such as a button. Furthermore, not every bean has to provide visual content on the screen.
• The JavaBeans architecture enables the application developer to rapidly and simply join one or more prewitten beans in a visual bean manipulation programme known as a beanbox to create a fully functional Java programme. Beans can also be manually coded into an application..
• Each bean exports a comprehensive array of properties, events, and methods that other beans can access. A property specifies an internal parameter that a bean can query or set programmatically. Beans interact with the "outside world" via events and open methods.
• In the best scenarios, prewritten beans appropriate to the desired application can be laid out in a graphical editor, their relationship defined, and their properties set through a visual iterative process, all with only minor coding required. Javabeans represent the pinnacle of code reuse and modular application development.
• Interoperability with other frameworks that adhere to the software component modal, like as COM and ActiveX, is one of the objectives of the Javabeans APi. A bean could be embedded in a little wrapper object of the right type to achieve this interoperability.

Steps to create a simple JavaBean

Steps 1:

Put this source code into a file named "SampleBeanExample.java"

import java.awt,*;

import java.io.Serializable;

public class SampleBeanExample extends Canvs implements Serializable

{

//Constructor sets inherits properties 

public SampleBeanExample(){

        setSize(60,40);

        setBackgroud(Color.yellow);

  }

}

Step 2: 

Compile the file 

javac SampleBeanExample.java

Step 3

Create a manifest file,named "manifest.tmp";

Step 4

Jar cfm SampleBeanExample.jar manifest.tmpSampleBeanExample.class

Then verify that the is corect by the comman "jar tf SampleBeanExpl.jar"

• The e option denotes your want to produce a JAR file.
• When you choose the f option, you tell the programme to output to a file rather than stdout.
• To include menifest data from an existing manifest file, use the m option.

Step 5

1.start the bean Box.

CD  to c:\program  Files\BDK1.1\beaanbox\

2.Load JAR into Bean Box By selecting "Loadjar" under the file menu.

Step 6

1.following the closing of the file selection dialogue box. If you shift your focus to the "toolBox" window, "\SampleBeanExample" will display at the bottom of the window.following the closing of the file selection dialogue box. If you shift your focus to the "toolBox" window, "\SampleBeanExample" will display at the bottom of the window.

2.Select SampleBeanExample.jar

3.The cursur will become a positive. You can now click and drag what will appear to be a coloured rectangle into the centre beanbox window.

Step 7

Try to change the yellow color with properties windows

and then type this  "run"

last step 8

To view what events SampleBeanExample can transmit, select "Events" from the "Edit" option in the centre window. These events are descended from java.awt.canvas.

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