Exception Handling in Java

Exception Handling in Java

What is Exception Handling?

• Exception handling is a mechanism to handle runtime errors in a program.
• It allows the program to continue executing even if an error occurs.

Types of Exceptions

• Checked Exceptions: These are exceptions that are checked by the compiler at compile-time.
• Unchecked Exceptions: These are exceptions that are not checked by the compiler at compile-time.
• Runtime Exceptions: These are exceptions that occur during the execution of a program.

Exception Handling Keywords

• try: A block of code where an exception may occur.
• catch: A block of code that handles the exception.
• finally: A block of code that is executed regardless of whether an exception occurs.
• throw: Used to throw an exception explicitly.
• throws: Used to declare an exception that a method may throw.

try-catch Block

• The try block contains the code that may throw an exception.
• The catch block contains the code to handle the exception.
• Multiple catch blocks can be used to handle different types of exceptions.

finally Block

• The finally block is executed regardless of whether an exception occurs.
• It is used to release resources, such as closing a file.

Exception Hierarchy

• Throwable: The parent class of all exceptions.
• Exception: The parent class of all checked exceptions.
• RuntimeException: The parent class of all unchecked exceptions.

Best Practices

• Handle specific exceptions: Catch specific exceptions rather than general exceptions.
• Handle exceptions close to the source: Handle exceptions as close to the source as possible.
• Log exceptions: Log exceptions to track and debug errors.
• Document exceptions: Document the exceptions that a method may throw.

Custom Exceptions

• Custom exceptions can be created by extending the Exception class.
• They can be used to provide more specific and meaningful error messages.

Exception Handling in Java

What is Exception Handling?

• A mechanism to handle runtime errors in a program, allowing it to continue executing even if an error occurs.

Types of Exceptions

• Checked Exceptions: Checked by the compiler at compile-time.
• Unchecked Exceptions: Not checked by the compiler at compile-time.
• Runtime Exceptions: Occur during the execution of a program.

Exception Handling Keywords

• try: A block of code where an exception may occur.
• catch: A block of code that handles the exception.
• finally: A block of code executed regardless of whether an exception occurs.
• throw: Used to throw an exception explicitly.
• throws: Used to declare an exception that a method may throw.

try-catch Block

• The try block contains code that may throw an exception.
• The catch block contains code to handle the exception.
• Multiple catch blocks can be used to handle different types of exceptions.

finally Block

• Executed regardless of whether an exception occurs.
• Used to release resources, such as closing a file.

Exception Hierarchy

• Throwable: The parent class of all exceptions.
• Exception: The parent class of all checked exceptions.
• RuntimeException: The parent class of all unchecked exceptions.

Best Practices

• Handle specific exceptions: Catch specific exceptions rather than general exceptions.
• Handle exceptions close to the source: Handle exceptions as close to the source as possible.
• Log exceptions: Log exceptions to track and debug errors.
• Document exceptions: Document the exceptions that a method may throw.

Custom Exceptions

• Can be created by extending the Exception class.
• Used to provide more specific and meaningful error messages.