In what cases is the Callable interface used in programming?

The Callable interface in Java is used when you need to execute a task that returns a result and can throw a checked exception. Unlike Runnable, which does not return a value and cannot throw checked exceptions, Callable allows:

• Running a task in a separate thread and obtaining the result via Future.
• Handling exceptions that may occur during execution.

Example of using Callable with ExecutorService:

import java.util.concurrent.*;

Callable<Integer> task = () -> {
    // Some computational task
    return 42;
};

ExecutorService executor = Executors.newSingleThreadExecutor();
Future<Integer> future = executor.submit(task);

try {
    Integer result = future.get();
    System.out.println("Result: " + result);
} catch (InterruptedException | ExecutionException e) {
    e.printStackTrace();
}
executor.shutdown();

Thus, Callable is suitable for asynchronous tasks where the result and error handling are important.