I want my class to be developed in such a way that no other class (even derived class) can create its objects. How can I do so?
512I want to control database connections in my program and want that only one thread should be able to make database connection at a time. How can I implement this logic?
630
What is type conversion in java?
What is a parameter in matrices?
Explain the difference between abstract classes and interfaces in java?
What is the purpose of the strictfp keyword?
What is the difference between a loader and a compiler?
What is independent and dependent variables in research?
What is the final class modifier?
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)
Explain OOPs concept.
How are variables stored?
Can we have more than one package statement in the source file?
placement papaers of spring computing technology
What is an association?
What are the important features of Java 10 release?
In a container there are 5 components. I want to display the all the components names, how will you do that one?