Your Java programs have followed the happy path so far. Every input is valid, every file exists, every number fits. That is not how real programs work. Users type letters where you expect digits. Files go missing. Networks drop.
In this section, I'll show you how Java handles unexpected problems through exceptions. You'll learn how to catch errors, throw your own, create custom exception classes, and manage resources that need cleanup. By the end, you'll write code that fails gracefully instead of crashing without explanation.