can we take more than one null values for Unique
constraints.
Answer Posted / aaa
Yes we can...
| Is This Answer Correct ? | 1 Yes | 1 No |
Post New Answer View All Answers
What is method overloading in java ?
What do you mean by jjs in java8?
What is this () in java?
What is string pooling concept?
How do you sort arraylist in descending order?
How can u increase the heap size in the memory?
Similarity and difference between static block and static method ?
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)
What does file separator do in java?
What is anagram of a string?
What is byte code and why is it important to java’s use for internet programming?
Why to use nested classes in java?
What is a parameter in java?
What is the purpose of a transient variable?
What is the difference between math floor and math round?