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Question 1

CompletableFuture Class

Answer 1

The CompletableFuture class is part of the Java Concurrency framework introduced in Java 8. It’s used for asynchronous programming and allows you to work with the result of asynchronous computations.

Here are some key points about the CompletableFuture class:

Asynchronous Execution: CompletableFuture allows you to perform tasks asynchronously. You can delegate a task to another thread and continue with other tasks.

Combining and Chaining: You can combine multiple CompletableFuture instances, chain them together, and perform further actions when the previous stage is completed.

Exception Handling: You can handle exceptions that occur during the execution of the asynchronous task.

Timeouts: You can set a timeout for the completion of a CompletableFuture, which is useful for managing tasks that take too long.

Cancellation: You can cancel a CompletableFuture if it’s no longer needed.

Here’s an example of using CompletableFuture to perform a simple asynchronous task:

java
Copy code
import java.util.concurrent.CompletableFuture;

public class CompletableFutureExample {
public static void main(String[] args) {
CompletableFuture<Integer> future = CompletableFuture.supplyAsync(() -> 42);</Integer>

    future.thenAccept(result -> {
        System.out.println("Result: " + result);
    });

    future.exceptionally(ex -> {
        System.err.println("Exception: " + ex);
        return null;
    });

    // This is a non-blocking operation, so the program doesn't wait for the result.
    System.out.println("Program continues...");

    // You can also join (block) to wait for the result:
    // int result = future.join();
} } In this example, we create a CompletableFuture that computes the value 42 asynchronously. We attach actions to it using thenAccept and handle exceptions using exceptionally. The program continues to run, and you can choose to wait for the result using join().

CompletableFuture is a powerful class that simplifies asynchronous programming in Java, making it easier to work with concurrent and parallel operations.