Challenge 2: A Checked Exception, Uncaught and Undeclared — Possible Solution
====================================================================

Broken attempt — FileDemo.java:

import java.nio.file.Files;
import java.nio.file.Path;

public class FileDemo {
    public void readFile(String path) {   // no throws, no try/catch
        Files.readAllBytes(Path.of(path));
    }
}

Representative compile error:

    FileDemo.java:5: error: unreported exception IOException; must be
    caught or declared to be thrown
        Files.readAllBytes(Path.of(path));
                           ^
    1 error

Fixed — FileDemo.java:

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;

public class FileDemo {
    public void readFile(String path) throws IOException {
        Files.readAllBytes(Path.of(path));
    }
}

Explanation:
Files.readAllBytes declares that it can throw the checked exception
IOException. Because IOException is checked (an Exception subtype
that isn't a RuntimeException), the compiler refuses to compile any
method that calls it without either catching IOException directly or
declaring throws IOException on the calling method itself, passing
the obligation up to ITS caller instead.

WHY THIS WORKS AS AN ANSWER
------------------------------
This reproduces the exact compiler-enforced requirement the chapter
describes for checked exceptions -- a real compile error, not a
runtime failure -- and resolves it using the throws clause, the
"side-channel" acknowledgment the chapter contrasts against Rust's
Result<T, E> living directly in the return type.