What it the root class for all Java classes ?
The Object class is the root class of all the Java classes.Reply
Why Java is not fully objective oriented ?
Java is not fully object oriented language,
because not all values in Java are Objects. The
basic numeric types such as int, long, double,
etc., are not objects and need to be "boxed" into
objects in order to pass them as Object
parameters or call methods on them. Java does not
support Multiple inheritance and operator
overloading. Java uses static keyword. We can
perform a function declared as static without an
object this violates real world reflection and
What is the use of Interface ?
Java acheive inheritance using two notions : By
extending the class and implementing the
interace. When you "implement" an interface, you
are stipulating that your class adheres to the
"contract" of the interface that you specified.
Use interfaces to say "What objects can do" or
"What can be done to an object. "Interfaces are
intended to define the what without defining the
how. Interfaces provide a form of multiple
inheritance. A class can extend only one other
class. Interfaces are limited to public methods
and constants with no implementation.
What is difference in between Java Class and Bean ?
The Java Bean is simple java class which is
contains Getters and Setters methods nothing
else. These methods can only used to set or get
the values of the variables. They neither contain
any business logic nor do they interact with the
Whereas a plain old java class contains the
businees logic, provides some data processing
capabilities, database interaction, etc.
What is light weight component ?
AWT supports lightweight components. Light weight
componenets can be created using Java without
mixing any other language code. A light weight
component is one that subclasses
java.awt.Component (or java.awt.Container)
directly - implementing the look-and-feel of the
component in Java rather than delegating the
look-and-feel to a native peer.
What is the corresponding Layout for Card in Swing ?
The corresponding Layout for Card in Swing CardLayout.Reply
How will you add panel to a Frame ?
We can add panel to a Frame :
Panel p = new Panel();
Frame f =new Frame("My frame");
What is the Layout for ToolBar ?
The layout for toolbar is Flow Layout. There is no
Specific Layout for adding ToolBar.You can use null
layout for use a toolbar at the position where you
want. You can also use DefaultToolBarLayout.
Is there any tag in HTML to upload and download files ?
The following tag is used for this purpose :
<input type=file name = "MyFile"> tag upload file.Reply
What is the base class for all swing components ?
All the swing components are derived from abstract javax.swing.JComponent class.