Question 1

Which statement is static and synchronized in JDBC API?

Accepted Answer

The getConnection() method is static and synchronized in the JDBC API, as it is used to establish a connection to the database.

Question 2

Which driver is efficient and always preferable for using JDBC applications?

Accepted Answer

Type-4 drivers, also known as thin drivers, are the most efficient among JDBC drivers because they convert JDBC calls directly into the vendor-specific database protocol. This direct conversion eliminates the need for additional translation or middleware layers, allowing for better performance and portability across different platforms.

Question 3

Which one of the following does not extends java.awt.Component

Accepted Answer

CheckboxGroup does not extend java.awt.Component; it is a class used for grouping together a set of Checkbox buttons, but itself is not a component that can be added to a GUI. CheckBox, Canvas, and Label are all AWT components that extend java.awt.Component and can be directly added to a GUI.

Question 4

What is default layout manager for panels and applets?

Accepted Answer

The default layout manager for panels and applets in Java is FlowLayout. This layout manager lays out components in a left-to-right flow, much like lines of text in a paragraph.

Question 5

java.awt.Component class method getLocation() returns Point (containg x and y cordinate).What does this x and y specify

Accepted Answer

The x and y coordinates returned by the getLocation() method of the java.awt.Component class specify the position of the component's upper-left corner in the coordinate space of the component's parent.

Question 6

Which of the following methods finds the maximum number of connections that a specific driver can obtain?

Accepted Answer

The correct method is DatabaseMetaData.getMaxConnections(), which retrieves the maximum number of active connections that the database can handle at one time.

Question 7

What is the disadvantage of Type-4 Native-Protocol Driver?

Accepted Answer

Type-4 drivers are specific to a database due to their design, which converts JDBC calls directly into the vendor-specific database protocol. This means for each database, a different Type-4 driver is required at the client side.

Question 8

What is the preferred way to handle an object's events in Java 2?

Accepted Answer

The preferred way to handle an object's events in Java 2 is by adding one or more event listeners to handle the events. This approach follows the Observer design pattern, allowing objects to subscribe to events they are interested in and handle them through the implementation of event listener interfaces. This method promotes loose coupling between the event source and the event listeners.

Question 9

Which component method is used to access a component's immediate container?

Accepted Answer

The getParent() method is used to access a component's immediate container in many GUI frameworks. It returns the parent container in which the component is placed.

Question 10

Which of the following creates a List with 5 visible items and multiple selections enabled?

Accepted Answer

The constructor List(int rows, boolean multipleMode) creates a new list with the specified number of visible rows and the specified multiple selection mode. Therefore, List(5, true) creates a List with 5 visible items and multiple selections enabled.

Question 11

An Applet has its Layout Manager set to the default of FlowLayout. What code would be the correct to change to another Layout Manager?

Accepted Answer

The correct way to change the layout manager of an applet (or any container in AWT and Swing) is to call the `setLayout` method with an instance of the desired layout manager. In this case, `new GridLayout(2,2)` creates a grid layout with 2 rows and 2 columns, and `setLayout(new GridLayout(2,2))` applies it to the container.

Question 12

How do you change the current layout manager for a container?

Accepted Answer

The setLayout method is used to change the current layout manager of a container in Java Swing and AWT.

Question 13

Which of the following methods can be used to draw the outline of a square within a JAVA.awt.Component object?

Accepted Answer

C  D  drawLine() can be used to draw each side of the square individually. drawPolygon() can be used to draw a square by specifying the four corner points.

Question 14

State true or false
(i) JPanel is a class included in awt package
(ii) Anonymous classes are mostly used for event handling
(iii) Names of anonymous classes must be unique
(iv) JOptionPane is an inner class

Accepted Answer

(i) JPanel is part of the javax.swing package, not the awt package. (ii) Anonymous classes are indeed often used for event handling in Java, especially in GUI programming. (iii) Anonymous classes, by definition, do not have a name, so they cannot be unique or otherwise. (iv) JOptionPane is not an inner class; it is a part of the javax.swing package used for simple dialogs.

Question 15

State true or false
(i) Java RMI supports distributed objects written entirely in java
(ii) Java RMI makes use of stubs and skeleton
(iii) In Java RMI an object registers itself with a media server
(iv) IDL is interface declaration language

Accepted Answer

(i) True - Java RMI (Remote Method Invocation) is specifically designed to support the invocation of methods that reside on different machines, and it is intended for use with Java objects, thus supporting distributed objects written entirely in Java. (ii) True - Java RMI indeed utilizes stubs and skeletons to facilitate remote method calls. The stub acts on the client side as a proxy for the remote object, while the skeleton resides on the server side to handle incoming method calls. (iii) False - In Java RMI, an object does not register itself with a media server; instead, it typically registers with the RMI registry, which allows other objects to locate it by name. (iv) False - IDL stands for Interface Definition Language, not Interface Declaration Language. It is used to define interfaces in a language-neutral way, allowing for communication between software components that do not share a language.

Question 16

Match the following
(a) Datagram Socket (i) UDP connection
(b) URL (ii) provides a necessary framework of debugging java programs
(c) java.net (iii) makes it possible to communicate over a network with java programs
(d) sun.tools.debug (iv) is a java object that represents WWW address

Accepted Answer

- Datagram Socket is used for sending and receiving datagram packets over a network, which is a characteristic of UDP (User Datagram Protocol).- URL (Uniform Resource Locator) is indeed a Java object that represents a World Wide Web address.- The java.net package provides the classes and interfaces for networking capabilities in Java, allowing communication over a network.- sun.tools.debug is part of the JDK's internal tools and provides a framework for debugging Java programs, though it's less commonly used directly by developers in favor of more integrated solutions in IDEs.

Question 17

State true or false
(i) public can only be assigned to class
(ii) protected protects a statement
(iii) protected method is never accessible outside the package
(iv) friendly variable may be accessible outside class

Accepted Answer

(i) Public can be assigned to class, interface, method, and variable.(ii) Protected protects a method or variable.(iii) Protected method is accessible outside the package through inheritance.(iv) Friendly variable is accessible outside the class but within the package.

Question 18

Which refers to a channel through which data flow from the source to the destination:

Accepted Answer

A stream refers to a sequence or flow of data moving from a source to a destination, facilitating data transfer or communication between different parts of a program or between programs.

Question 19

The ________ method help in clearing the contents of the buffer:

Accepted Answer

The answer of The ________ method help in clearing the...

Question 20

Which of these methods can be used to output a string in an applet?

Accepted Answer

The method drawString() is used in Java applets to output text to the applet's display area. It is a method of the Graphics class, allowing you to specify the text to be displayed and its position.

Quiz 11: Java Programming : JDBC API, Layout Managers, and Event Handling