Java Runnable lambda with arguments

Java Runnable lambda with arguments

Here's an explanation of Java's Runnable interface and how to use it with a lambda expression, including passing arguments:

In Java, the Runnable interface represents a task that can be executed by a separate thread. The most important method in this interface is run(), which contains the code you want to run when the Runnable is executed.

You can create an instance of Runnable and then pass it to a Thread object's constructor, like so:

class MyRunnable implements Runnable {
public void run() {
System.out.println("Hello from my runnable!");
}
}
public class Main {
public static void main(String[] args) {
Thread t = new Thread(new MyRunnable());
t.start();
}
}

However, since Java 8, you can use lambda expressions to create a Runnable instance more concisely. Here's how:

public class Main {
public static void main(String[] args) {
Runnable myRunnable = () -> System.out.println("Hello from my runnable!");
Thread t = new Thread(myRunnable);
t.start();
}
}

In this example, we're using an anonymous class to implement Runnable. Inside the lambda expression, we're defining the run() method. The lambda is essentially saying: "When you execute me, print 'Hello from my runnable!'". You can also pass arguments to your lambda like so:

public class Main {
public static void main(String[] args) {
Runnable myRunnable = (name) -> System.out.println("Hello " + name + "!");
Thread t = new Thread(() -> myRunnable.run("John"));
t.start();
}
}

In this example, we're creating a Runnable instance that takes a String argument. When the Runnable is executed, it prints out a greeting message with the provided name.

Keep in mind that lambdas can be reused and are very flexible, so you could easily create reusable code with them.

Here's an example of a Runnable that calculates the sum of two numbers:

public class Main {
public static void main(String[] args) {
Runnable myRunnable = (a, b) -> System.out.println("The sum is: " + (a + b));
Thread t = new Thread(() -> myRunnable.run(5, 10));
t.start();
}
}

In this example, we're creating a Runnable instance that calculates the sum of two numbers and prints it out. You could reuse this code by passing different arguments to the lambda.

Java's Runnable interface is very powerful and versatile. By using lambdas with Runnable, you can create concise and reusable code for performing tasks in separate threads.

What is runnable in Java?

I'll respond in English, but don't worry, your grandma won't be too upset.

In the context of Java programming, "runnable" refers to a type of object that can run (or execute) as an independent unit of code. In other words, it's an object that can be started and stopped independently, similar to how a thread runs.

In Java, a Runnable is an interface defined in the java.lang package. It has a single abstract method called run() which represents the code to be executed when the Runnable is run.

To create a Runnable, you need to implement this interface and provide an implementation for the run() method. The run() method contains the code that you want to execute, such as performing some tasks, processing data, or interacting with other parts of your program.

Here's an example of how to create a simple Runnable:

// Define a Runnable interface implementation
public class MyRunnable implements Runnable {
public void run() {
// Code to be executed when the Runnable is run
System.out.println("Hello from MyRunnable!");
}
}

Once you have created a Runnable, you can execute it in various ways, such as:

public class Main {
public static void main(String[] args) {
// Create a Thread with the MyRunnable
Thread t = new Thread(new MyRunnable());
t.start();
}
}

public class Main {
public static void main(String[] args) {
// Create an ExecutorService and submit the MyRunnable
ExecutorService executor = Executors.newSingleThreadExecutor();
executor.submit(new MyRunnable());
// Shut down the ExecutorService when done
executor.shutdown();
}
}

public class Main {
public static void main(String[] args) {
// Create a ForkJoinPool and submit the MyRunnable
ForkJoinPool pool = new ForkJoinPool();
pool.submit(new MyRunnable());
// Shut down the ForkJoinPool when done
pool.shutdown();
}
}

In summary, a Runnable in Java represents an independent unit of code that can be executed by various means such as threads or executor services.