Answer Posted / prasanna

If two objects are equal then there hashcode must same.

Write a method that will remove given character from the string?

1083

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Difference between method overloading and overriding.

1134

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When should I use stringbuffer?

1056

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What are keywords and reserved words in java?

1115

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What do you mean by collectors in java 8?

981

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What is set string?

1291

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Can we increase array size dynamically in java?

1011

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What is difference between classpath and path variables in java?

1256

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What is a control variable example?

1078

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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)

1995

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What is balanced tree in java?

1016

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Can array grow dynamically in java?

1029

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Which java version is latest?

1086

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What is the use of jtable?

1166

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Which collection is thread safe in java?

1038

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