Notice: Undefined index: alg in /home/u681245571/domains/studyglance.in/public_html/labprograms/r22javadisplay.php on line 82

Notice: Undefined index: url2 in /home/u681245571/domains/studyglance.in/public_html/labprograms/r22javadisplay.php on line 84

Notice: Undefined index: url3 in /home/u681245571/domains/studyglance.in/public_html/labprograms/r22javadisplay.php on line 85

Notice: Undefined index: url4 in /home/u681245571/domains/studyglance.in/public_html/labprograms/r22javadisplay.php on line 86

Notice: Undefined index: opurl2 in /home/u681245571/domains/studyglance.in/public_html/labprograms/r22javadisplay.php on line 89

Notice: Undefined index: opurl3 in /home/u681245571/domains/studyglance.in/public_html/labprograms/r22javadisplay.php on line 90

Notice: Undefined index: opurl4 in /home/u681245571/domains/studyglance.in/public_html/labprograms/r22javadisplay.php on line 91

Notice: Undefined index: opurl5 in /home/u681245571/domains/studyglance.in/public_html/labprograms/r22javadisplay.php on line 92

Java Programming [ Lab Programs ]

---

Aim:

Write a Java program to handle checked and unchecked exceptions. Also, demonstrate the usage of custom exceptions in real time scenario.

Source Code:

ExceptionsDemo.java

import java.io.File;

import java.io.FileReader;

import java.io.FileNotFoundException;



// Custom Exception

class InvalidAgeException extends Exception {

    public InvalidAgeException(String message) {

        super(message);

    }

}



public class ExceptionsDemo {

     // Method to demonstrate custom exception

    public static void register(String name, int age) throws InvalidAgeException {

        if (age < 18) {

            throw new InvalidAgeException("User must be at least 18 years old.");

        } else {

            System.out.println("Registration successful for user: " + name);

        }

    }

    public static void main(String[] args) {

        //Handling Checked Exception 

        try {

            File file = new File("myfile.txt");

            // This line can throw FileNotFoundException

            FileReader fr = new FileReader(file);     

        } catch (FileNotFoundException e) {

            System.out.println("File not found: " + e.getMessage());

        }

        //Handling Unchecked Exception 

        try {

            int[] arr = {1, 2, 3};

            // Accessing an out-of-bound index

            System.out.println(arr[6]); 

        } catch (ArrayIndexOutOfBoundsException e) {

            System.out.println("Array index out of bounds: " + e.getMessage());

        }

        // Finally block to perform cleanup operations

        finally {

            System.out.println("Cleanup operations can be performed here.");

        }

        // Demonstrate custom exception handling

        System.out.println("Demonstrating Custom Exception:");

        try {

            // Invalid age for registration

            register("Madhu", 17); 

        } catch (InvalidAgeException e) {

            System.out.println("Custom Exception Caught: " + e.getMessage());

        }

    }

}

Output:

---

Related Content :

Java Programming Lab Programs

1) Use eclipse or Netbean platform and acquaint with the various menus, create a test project, add a test class and run it see how you can use auto suggestions, auto fill. Try code formatter and code refactoring like renaming variables, methods and classes. Try debug step by step with a small program of about 10 to 15 lines which contains at least one if else condition and a for loop. View Solution

2) Write a Java program to demonstrate the OOP principles. [i.e., Encapsulation, Inheritance, Polymorphism and Abstraction] View Solution

3) Write a Java program to handle checked and unchecked exceptions. Also, demonstrate the usage of custom exceptions in real time scenario. View Solution

4) Write a Java program on Random Access File class to perform different read and write operations. View Solution

5) Write a Java program to demonstrate the working of different collection classes. [Use package structure to store multiple classes]. View Solution

6) Write a program to synchronize the threads acting on the same object. [Consider the example of any reservations like railway, bus, movie ticket booking, etc.] View Solution

7) Write a program to perform CRUD operations on the student table in a database using JDBC. View Solution

8) Write a Java program that works as a simple calculator. Use a grid layout to arrange buttons for the digits and for the +, -,*, % operations. Add a text field to display the result. Handle any possible exceptions like divided by zero. View Solution

9) Write a Java program that handles all mouse events and shows the event name at the center of the window when a mouse event is fired. [Use Adapter classes] View Solution

---