Introspection
It is the self-examination of one’s conscious thoughts and feelings. [reference: Wikipedia]

Java Bean Introspection
It is the examination provided by a Java Bean class! But a class cannot speak. A developer has to write the description about the bean so that Other developers can understand the Bean properties/methods/events etc.
In short, The process to describe a Bean is known as Bean Introspection.

Which is done by two ways:

1. Naming Conventions(What we did in previous tutorial – Link)
2. By writing an additional class that extends the BeanInfo interface

In Brief:
1. Naming Conventions.

• Simple/Single Property:

      private int id;
      public void setId(int id) 
      {
          this.id = id;
      }
  
      public String getName() 
      {
          return name;
      }
  

• Indexed Property:

  private double data[ ];
  public double getData(int index) 
  {
  	return data[index];
  }
  public void setData(int index, double value) 
  {
  	data[index] = value;
  }
  public double[ ] getData( ) 
  {
  	return data;
  }
  public void setData(double[ ] values) 
  {
  	data = new double[values.length];
  	System.arraycopy(values, 0, data, 0, values.length);
  }
  

• Events:

  public void addEventListener(EventListener e) 
  {
  	// code
  }
  public void removeEventListener(EventListener e) 
  {
  	// code
  }
  

2. By writing an additional class that extends the BeanInfo interface

The BeanInfo interface enables us to explicitly control what information is available in a Bean. The BeanInfo interface defines following:

PropertyDescriptor[ ] getPropertyDescriptors( )
EventSetDescriptor[ ] getEventSetDescriptors( )
MethodDescriptor[ ] getMethodDescriptors( )

Now we are going to describe all the properties of Employee.class by using java.beans.SimpleBeanInfo(Derived from BeanInfo Interface):

• Property Descriptor:

  import java.beans.SimpleBeanInfo;
  public class EmployeeBeanInfo extends SimpleBeanInfo 
  {
  	public PropertyDescriptor[] getPropertyDescriptors() 
  	{
  		try 
  		{
  			PropertyDescriptor pdId = new PropertyDescriptor("id", Employee.class);
  			PropertyDescriptor pdName = new PropertyDescriptor("name", Employee.class);
  			PropertyDescriptor pdContact = new PropertyDescriptor("contact", Employee.class);
  			PropertyDescriptor pd[] = {pdId, pdName, pdContact};
  			return pd;
  		}
  		catch(Exception e) 
  		{
  			System.out.println("Exception caught. " + e);
  		}
  	return null;
  	}
  }
  

Same way we can describe Events and Methods of the Bean class.