How to run two classes in parallel using multithreading?

Question

I am working on a project in which I have several interfaces and two implementation classes that need to implement these two interfaces.

Suppose my first interface is

public Interface interfaceA {
    public String abc() throws Exception;
}

And its implementation is

public class TestA implements interfaceA {

    // abc method
}

I call it this:

TestA testA = new TestA();
testA.abc();

Now my second interface is

public Interface interfaceB {
    public String xyz() throws Exception;
}

And its implementation is

public class TestB implements interfaceB {

    // xyz method   
}

I call it this:

TestB testB = new TestB();
testB.xyz();

Problem: -

Now my question is: is there a way I can execute these two implementation classes in parallel? I do not want to run it sequentially.

Meaning, I want to run a parallel implementation TestAand TestB? Can this be done?

Answer 1

, . . .

    final ExecutorService executorService = Executors.newFixedThreadPool(2);
    final ArrayList<Callable<String>> tasks = Lists.newArrayList(
            new Callable<String>()
            {
                @Override
                public String call() throws Exception
                {
                    return testA.abc();
                }
            },
            new Callable<String>()
            {
                @Override
                public String call() throws Exception
                {
                    return testB.xyz();
                }
            }
    );

    executorService.invokeAll(tasks);

. InvokeAll Future.

    final List<Future<String>> futures = executorService.invokeAll(tasks);
    for (Future<String> future : futures)
    {
        final String resultOfTask = future.get();
        System.out.println(resultOfTask);
    }

, Callable, , . TestB:

public interface interfaceB {
    String xyz() throws Exception;
}

public class TestB implements interfaceB, Callable<String>{

    @Override
    public String xyz() throws Exception
    {
        //do something
        return "xyz"; 
    }

    @Override
    public String call() throws Exception
    {
        return xyz();
    }
}

Lists.newArrayList(new TestB(), new TestA());

final ArrayList<Callable<String>> tasks = Lists.newArrayList(
            new Callable<String>()
            {
                @Override
                public String call() throws Exception
                {
                    return testA.abc();
                }
            },
            new Callable<String>()
            {
                @Override
                public String call() throws Exception
                {
                    return testB.xyz();
                }
            }
    );

, Thread, .

Answer 2

. -

ThreadA{

  public void run(){
      TestA testA = new TestA();
      testA.abc();
  }
}

...

ThreadB{

  public void run(){
      TestB testB = new TestB();
      testB.xyz();
  }
}

-

public static void main(String[] args){
    new ThreadA().start();
    new ThreadB().start();
}

Answer 3

Try this one

Collect all classes of the same interface and call them in Multi threading.

Use the callback mechanism to return the result.

import java.util.ArrayList;
import java.util.List;

public class Demo123 {
    public static void main(String[] args) {

        List<InterfaceA> a = new ArrayList<InterfaceA>();
        List<InterfaceB> b = new ArrayList<InterfaceB>();

        TestA testA = new TestA();
        TestB testB = new TestB();

        a.add(testA);
        b.add(testB);

        for (final InterfaceA i : a) {
            new Thread(new Runnable() {

                @Override
                public void run() {
                    try {
                        i.callback(i.abc());
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }).start();
        }

        for (final InterfaceB i : b) {
            new Thread(new Runnable() {

                @Override
                public void run() {
                    try {
                        i.callback(i.xyz());
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }).start();
        }

    }
}

interface MyCallback {
    public void callback(String value);
}

interface InterfaceA extends MyCallback {
    public String abc() throws Exception;
}

class TestA implements InterfaceA {

    @Override
    public String abc() throws Exception {
        return "abc";
    }

    @Override
    public void callback(String value) {
        System.out.println("value returned:" + value);
    }
}

interface InterfaceB extends MyCallback {
    public String xyz() throws Exception;
}

class TestB implements InterfaceB {

    @Override
    public String xyz() throws Exception {
        return "xyz";
    }

    @Override
    public void callback(String value) {
        System.out.println("value returned:" + value);
    }
}

Answer 4

You can try the following:

public static void main(String[] args) throws InterruptedException {
    Executors.newCachedThreadPool().invokeAll(Arrays.asList(
        new Callable<String>() {
            @Override public String call() { return new TestA().abc(); }
        },
        new Callable<String>() {
            @Override public String call() { return new TestB().xyz(); }
        }));
}

public interface InterfaceA {
    public String abc() throws Exception;
}

public interface InterfaceB {
    public String xyz() throws Exception;
}

class TestA implements InterfaceA {
    @Override public String abc() {
        System.out.println("Inside A"); return null;
    }
}

class TestB implements InterfaceB {

    @Override public String xyz() {
        System.out.println("Inside B"); return null;
    }
}