使用同一接口的对象并在锁中执行工作的队列

如前所述,您可以使用 ExecutorService 实例并将命令作为任务提交给它。下面是一个示例实现。

public class BasicCommand implements Command, Callable<Integer>{

private int operationId;

public BasicCommand(int operationId) {
    this.operationId = operationId;
}

public Integer call(){
    this.execute();
    return operationId;
}

@Override
public void execute() {
    //Log.d("BasicCommand", "Id: " + operationId);
    System.out.println("hello executing command" + operationId);
}

public static void main(String[] args) throws Exception {


    ExecutorService exceutorService= Executors.newSingleThreadExecutor();
    exceutorService.submit(new BasicCommand(1));
    Future future =exceutorService.submit(new BasicCommand(2));
    System.out.println("result:" +future.get());

}

由于您希望按顺序执行这些命令,我建议使用生产者-消费者模式,您可以使用两个线程和一个阻塞队列来实现这一点。

基本上,制片人会尝试推出新的 Command 在队列中,消费者将尝试将其取出。阻塞队列将处理生产者和消费者之间的同步问题。

例子:

import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingDeque;

public class Main {

    public static void main(String[] args) throws Exception {
        BlockingQueue<Command> commands = new LinkedBlockingDeque<>();
        new Thread(new Consumer(commands)).start();
        new Thread(new Producer(commands)).start();
    }
}

class Consumer implements Runnable {

    BlockingQueue<Command> commands;

    public Consumer(BlockingQueue<Command> commands) {
        this.commands = commands;
    }

    @Override
    public void run() {
        Command command;
        try {
            while ((command = commands.take()) != null) {
                command.execute();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

class Producer implements Runnable {

    BlockingQueue<Command> commands;

    public Producer(BlockingQueue<Command> commands) {
        this.commands = commands;
    }

    @Override
    public void run() {
        while (true) {
            try {
                commands.put(new Command() {
                    @Override
                    public void execute() {
                        System.out.println("Command");
                    }
                });
                Thread.sleep(1000);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}