Is string a wrapper class?

1014

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)

1945

How do you find the maximum number from an array without comparing and sorting?

1119

What is meant by object oriented programming – oop?

988

What is args length in java?

1169

Can we override constructors in java?

1127

What do you understand by access specifiers in Java?

1010

how would you implement a thread pool? : Java thread

906

Why hashset is used in java?

1067

How do you remove duplicates from an array in java?

952

How do you classify Dialog Box?

1111

Difference between final and effectively final ? Why is effectively final even required ?

985

Difference between a class and an object?

1026

Which one of the following suits the description of a string better: derived or primitive?

950

Is binary a low level language?

916