Exception handling in Java

Exception handling is an essential concept in Java programming. It allows you to handle unexpected errors and problems that may occur during the execution of your code. In this tutorial, we’ll introduce you to exception handling in Java and show you how to use it in your code.

What is an exception?

An exception is an error that occurs during the execution of a program. It may be caused by an unexpected event, such as a file that doesn’t exist or a network connection that’s lost. When an exception occurs, the Java runtime system creates an exception object that contains information about the error, such as its type and message.

Handling exceptions

To handle exceptions in Java, you use a try-catch block. A try-catch block is used to enclose a section of code that may generate an exception. Here’s an example of how to use a try-catch block in Java:

try {
  // Code that may generate an exception
  int result = 1 / 0;
} catch (ArithmeticException e) {
  // Code to handle the exception
  System.out.println("An error occurred: " + e.getMessage());
}

In this example, we’ve enclosed a division operation that may generate an ArithmeticException inside a try block. If the exception occurs, the catch block is executed, and an error message is printed to the console.

Throwing exceptions

Sometimes, you may want to create your own exception to handle a specific error in your code. To do this, you use the throw keyword. Here’s an example of how to throw an exception in Java:

public void withdraw(int amount) throws InsufficientFundsException {
  if (amount > balance) {
    throw new InsufficientFundsException("Not enough funds.");
  } else {
    balance -= amount;
  }
}

In this example, we’ve created a method called withdraw that throws an InsufficientFundsException if the account balance is less than the withdrawal amount. If the exception is thrown, the calling code can catch it and handle it accordingly.

Conclusion

Exception handling is an essential concept in Java programming. It allows you to handle unexpected errors and problems that may occur during the execution of your code. To handle exceptions in Java, you use a try-catch block. If you need to create your own exception, you can use the throw keyword. With this knowledge, you’re now ready to start using exception handling in your own Java code.