Java Exception Handling

Think of a Java program like a machine that performs steps one after another.
Each step assumes everything is fine — inputs are correct, files exist, and resources are available.
But in real life, things don’t always work perfectly.

At any time:

• A user may enter the wrong input
• A file you need might be missing
• An internet resource may stop responding
• A calculation might produce an invalid result

These unexpected problems are called exceptions.

Now imagine there is no exception handling.

• If even one small error happens, the entire program would stop suddenly and show a messy error message.
• This is like stopping a whole factory just because one small machine had a minor issue.
• To avoid this complete shutdown, Java provides a system called exception handling.

Exception handling Keywords

try block( watches the part of code where an error might happen.)

catch block (catches the error, understands what went wrong, and handles it safely.)

finally block (runs important cleanup work (like closing files), no matter what happens.)

throw (lets you create your own error intentionally.)

throws (tells other parts of the program that this method might produce an error.)

Instead of stopping the whole program, Java isolates the error, fixes or handles it, and allows the program to continue.

What Is an Exception?
An exception is an event, which occurs during the execution of a program, that disrupts the normal flow of the program's instructions.