Sample code to retrieve objects from HashMap in sorted ascending order?

Hi Friends, can u give code to convert ArrayList to HashMap and HashMap to ArrayList.

Hi ,i convert contrller as jSp And presentation as servlet ...will it do? if so what are advantage and idsadvantages

IBM,

Can u give me sample code for ServiceImpl and DaoImpl, in j2ee .

In ActionClass we can use only one action i.e execute(), but in DispatchAction we can use multiple actions.My question is , we can use multiple actions in Action class if(action.equals("add") if(action.equals("update"). Then when to use Action and DispatchAction which is frequently in webapplications.

what is java

Tech Mahindra,

what is Inheritense

Tech Mahindra,

what is multi-tasking

Anand Group, Photon Infotech, Tech Mahindra,

what is multitherading

Tech Mahindra,

What is Generic in java? Where can we write Generic ( class or method or objects or etc...)? with simple example? Thanks, Bose.

Infosys, Tech Mahindra,

i need example for java abstraction. where we use abstraction and why we need abstraction.

Oracle,

Consider that class classA, abstract class classB, and final classC have been defined.Which one of the following is correct? 1. classA extends classC implements classB 2. class A extends classB, classC 3. classA extends classB 4. classB implements classC

Draw a UML class diagram for the code fragment given below: public class StringApplet extends Applet { private Label sampleString; private Button showTheString; private ButtonHandler bHandler; private FlowLayout layout; public StringApplet() { sampleString = new Label(" "); showTheString = new Button (" Show the String"); bHandler = new ButtonHandler(); layout = new FlowLayout(); showTheString.addActionListener(bHandler); setLayout(layout); add(sampleString); add(showTheString); } class ButtonHandler implements ActionListener { public void actionPerformed(ActionEvent e) { samplestring.setText("Good Morning"); } } } Note: The methods need not be indicated on the diagram.

The following program reads data (details of students) from a file named students.txt and converts it into e-mail addresses. The results are written to a file named studentemail.txt. students.txt consists of a number of lines, each containing the data of a student in colon delimited format: Last Name:First Name:Student Number Each input record is converted to an e-mail address and written to studentemail.txt in the following format: the first character of the last name + the first character of the first name + the last four digits of the student number + “@myunisa.ac.za” import java.io.*; public class EmailConverter { public static void main(String[] args) throws IOException { BufferedReader input = new BufferedReader(new FileReader ("students.txt")); PrintWriter output = new PrintWriter(new FileWriter ("studentemail.txt")); String line = input.readLine(); while (line != null) { // Extract the information for each student String[] items = line.split(":"); // Generate the email address String email = "" + items[0].charAt(0) + items[1].charAt(0) + items[2].substring(4,8) + "@myunisa.ac.za"; email = email.toLowerCase(); // Output output.println(email); line = input.readLine(); } input.close(); output.close(); } } Rewrite the class so that it handles possible errors that may occur. In particular, it should do the following: • It should catch at least three appropriate exceptions that might occur, and display suitable messages. • At this stage, the program will not run correctly if there is an empty line in the input file. Change the program so that if an empty line is encountered, an exception is thrown and the empty line is ignored. This exception should be handled with the display of a suitable error message. • Before the e-mail address is added to the output file, check if the student number has 8 digits. If not, throw an InvalidFormatException (which the program should not handle itself)

Say you want to store the information about a number of pets in an array. Typical information that you could store for each pet (where relevant) would be • Breed of animal • Animal's name • Its birth date • Its sex • Whether it has been sterilised or not • When it is due for its next inoculation • When it last had its wings clipped For each type of pet (eg. dog, cat or bird) you would typically define a class to hold the relevant data. Note: You do not need to implement these classes. Just answer the following questions. 3.1.1 What would be the advantage of creating a superclass (eg. Pet) and declaring an array of Pet objects over simply using an array of Objects, storing each of the instances of the different pet classes (eg. Dog, Cat or Bird) in it? 3.1.2 Would you define Pet as a class or as an interface? Why? (2) (2)