In Java, you can create your own custom exceptions to handle specific error conditions in your code. This can be useful in situations where the standard Java exceptions do not provide enough detail or are not specific enough to your needs. Here’s an explanation of how to create a custom exception with an example:
To create a custom exception in Java, you must first create a class that extends the Exception class. Here’s an example:
public class InvalidAgeException extends Exception {
public InvalidAgeException(String message) {
super(message);
}
}In this example, we have created a custom exception called InvalidAgeException. This exception extends the Exception class, which is the base class for all exceptions in Java. The InvalidAgeException class has a constructor that takes a String argument, which is the message that will be associated with the exception.
Once you have created your custom exception class, you can use it in your code to handle specific error conditions. Here’s an example:
public static void checkAge(int age) throws InvalidAgeException {
if (age < 0 || age > 120) {
throw new InvalidAgeException("Invalid age: " + age);
}
}In this example, we have created a method called checkAge that takes an int argument. If the argument is less than zero or greater than 120, the method throws an InvalidAgeException with a message that indicates the invalid age. The throws keyword is used to declare that the method may throw an InvalidAgeException, so callers of the method must handle the exception appropriately.
By creating custom exceptions in your code, you can provide more detailed and specific error messages to users of your code. This can make it easier to diagnose and fix errors in your programs.