What is the purpose of the Callable interface in programming?

The Callable interface in Java is designed to represent tasks that can be executed in a separate thread and return a result. Unlike the Runnable interface, which does not return a value and cannot throw checked exceptions, Callable allows:

• Returning a result via the call() method.
• Throwing checked exceptions.

This is especially useful when working with thread pools and the ExecutorService class, where you can obtain a Future object to track the result of an asynchronous task.

Example of usage:

import java.util.concurrent.Callable;

public class SumTask implements Callable<Integer> {
    private int a, b;

    public SumTask(int a, int b) {
        this.a = a;
        this.b = b;
    }

    @Override
    public Integer call() {
        return a + b;
    }
}

Then, this task can be submitted to an ExecutorService and the result obtained via Future."}]}]}