Welcome to the World of Online Learning:
Hello Friends “This blog helps you to learn Java programming concepts. You can learn Java language at your own speed and time. One can learn concepts of Java language by practicing various programs given on various pages of this blog. Enjoy the power of Self-learning using the Internet.”
Write a Java Program to Create custom exception
PROGRAM: Java Program to Create custom exception
/*Java Program to Create custom exception*/
1: Java program to create custom checked exception
import java.util.ArrayList;
import java.util.Arrays;
// create a checked exception class
class CustomException extends Exception {
public CustomException(String message) {
// call the constructor of Exception class
super(message);
}
}
class Main {
ArrayList<String> languages = new ArrayList<>(Arrays.asList(“Java”, “Python”, “JavaScript”));
// check the exception condition
public void checkLanguage(String language) throws CustomException {
// throw exception if language already present in ArrayList
if(languages.contains(language)) {
throw new CustomException(language + ” already exists”);
}
else {
// insert language to ArrayList
languages.add(language);
System.out.println(language + ” is added to the ArrayList”);
}
}
public static void main(String[] args) {
// create object of Main class
Main obj = new Main();
// exception is handled using try…catch
try {
obj.checkLanguage(“Swift”);
obj.checkLanguage(“Java”);
}
catch(CustomException e) {
System.out.println(“[” + e + “] Exception Occured”);
}
}
}
2: Create custom unchecked exception class
import java.util.ArrayList;
import java.util.Arrays;
// create a unchecked exception class
class CustomException extends RuntimeException {
public CustomException(String message) {
// call the constructor of RuntimeException
super(message);
}
}
class Main {
ArrayList<String> languages = new ArrayList<>(Arrays.asList(“Java”, “Python”, “JavaScript”));
// check the exception condition
public void checkLanguage(String language) {
// throw exception if language already present in ArrayList
if(languages.contains(language)) {
throw new CustomException(language + ” already exists”);
}
else {
// insert language to ArrayList
languages.add(language);
System.out.println(language + ” is added to the ArrayList”);
}
}
public static void main(String[] args) {
// create object of Main class
Main obj = new Main();
// check if language already present
obj.checkLanguage(“Swift”);
obj.checkLanguage(“Java”);
}
}
