IGNOU BCA MCA Students - VIVA Question Answer for JAVA APPLET Part IX

IGNOU BCA MCA Students - VIVA Question Answer for JAVA APPLET

JAVA APPLET or JSP Selected Question Answer - PART IX

61. Name three Component subclasses that support painting. The Canvas, Frame, Panel, and Applet classes support painting.

62. What is clipping ? Clipping is defined as the process of confining paint operations to a limited area or shape.

63. What is the difference between a MenuItem and a CheckboxMenuItem ? The CheckboxMenuItem class extends the MenuItem class and supports a menu item that may be either checked or unchecked.

64. How are the elements of a BorderLayout organized ? The elements of a BorderLayout are organized at the borders (North, South, East, and West) and the center of a container.

65. How are the elements of a GridBagLayout organized ? The elements of a GridBagLayout are organized according to a grid. The elements are of different sizes and may occupy more than one row or column of the grid. Thus, the rows and columns may have different sizes.

66. What is the difference between a Window and a Frame ? The Frame class extends the Window class and defines a main application window that can have a menu bar.

67. What is the relationship between clipping and repainting ? When a window is repainted by the AWT painting thread, it sets the clipping regions to the area of the window that requires repainting.

68. What is the relationship between an event-listener interface and an event-adapter class ? An event-listener interface defines the methods that must be implemented by an event handler for a particular event. An event adapter provides a default implementation of an event-listener interface.

69. How can a GUI component handle its own events ? A GUI component can handle its own events, by implementing the corresponding event-listener interface and adding itself as its own event listener.

70. What advantage do Java’s layout managers provide over traditional windowing systems ? Java uses layout managers to lay out components in a consistent manner, across all windowing platforms. Since layout managers aren’t tied to absolute sizing and positioning, they are able to accomodate platform-specific differences among windowing systems.

71. What is the design pattern that Java uses for all Swing components ? The design pattern used by Java for all Swing components is the Model View Controller (MVC) pattern.

JDBC Question Answer Starts Here

72. What is JDBC ? JDBC is an abstraction layer that allows users to choose between databases. JDBC enables developers to write database applications in Java, without having to concern themselves with the underlying details of a particular database.

73. Explain the role of Driver in JDBC. The JDBC Driver provides vendor-specific implementations of the abstract classes provided by the JDBC API. Each driver must provide implementations for the following classes of the java.sql package:Connection, Statement, PreparedStatement, CallableStatement, ResultSet and Driver.

74. What is the purpose Class.forName method ? This method is used to method is used to load the driver that will establish a connection to the database.

75. What is the advantage of PreparedStatement over Statement ? PreparedStatements are precompiled and thus,their performance is much better. Also, PreparedStatement objects can be reused with different input values to their queries.

76. What is the use of CallableStatement ? Name the method, which is used to prepare a CallableStatement.A CallableStatement is used to execute stored procedures. Stored procedures are stored and offered by a database. Stored procedures may take input values from the user and may return a result. The usage of stored procedures is highly encouraged, because it offers security and modularity.The method that prepares a CallableStatement is the following:

1	CallableStament.prepareCall();

77. What does Connection pooling mean ? The interaction with a database can be costly, regarding the opening and closing of database connections. Especially, when the number of database clients increases, this cost is very high and a large number of resources is consumed.A pool of database connections is obtained at start up by the application server and is maintained in a pool. A request for a connection is served by a connection residing in the pool. In the end of the connection, the request is returned to the pool and can be used to satisfy future requests.