File Handling in Java: Reading, Writing, and Managing Files with Examples

Error Handling in Java

1. What are Exceptions?
 Exceptions are events that disrupt the normal flow of the program and can
occur during runtime. They represent errors or other exceptional conditions
that need to be handled.
 Java uses try-catch blocks to handle exceptions.
 There are two main types of exceptions in Java:
o Checked Exceptions: Exceptions that the compiler forces you to
handle (e.g., IOException, SQLException).
o Unchecked Exceptions: Exceptions that occur due to programming
errors, such as logical errors or improper use of APIs (e.g.,
NullPointerException, ArrayIndexOutOfBoundsException).



2. Try-Catch Block
 A try block is used to wrap the code that might throw an exception.
 A catch block handles the exception and prevents the program from
crashing.

Syntax:

try {
// Code that might throw an exception
} catch (ExceptionType e) {
// Handle the exception
}

Example:

public class Main {
public static void main(String[] args) {
try {

, int result = ; // ArithmeticException
} catch (ArithmeticException e) {
System.out.println("Cannot divide by zero!");
}
}
}

Important Points:

 You can have multiple catch blocks for handling different types of
exceptions.
 The catch block can catch specific types of exceptions or the generic
Exception class.



3. Finally Block
 The finally block is optional and is used to execute code that must run
regardless of whether an exception occurs or not (e.g., closing files or
releasing resources).
 It is executed after the try block, whether an exception is thrown or not.

Syntax:

try {
// Code that might throw an exception
} catch (ExceptionType e) {
// Handle the exception
} finally {
// Code to be executed after try-catch, like resource cleanup
}

Example:

public class Main {
public static void main(String[] args) {
try {
System.out.println("Trying to open a file...");