Question

有人会指出在哪里可以使用onComplete回调找到Command模式的实现，例如在串行宏命令中可以使用？

纳斯

Answer 1

试试这个

abstract class Command {
    final public void execute(){
          run();
          onComplete();
    }
    protected abstract void run();
    protected abstract void onComplete();
}
//usage
abstract class HiCommand extends Command {
    protected void run(){
        System.out.println("Hi, ");
    }

    protected abstract void onComplete();
}

new HiCommand(){
    @Override
    protected void onComplete() {
        System.out.println("world");
    }
}.execute();

或者

interface WhenDone{
    void onComplete();
}

abstract class Command {
    private final WhenDone callback;
    protected Command(WhenDone callback){
        this.callback = callback;
    }
    final public void execute(){
          run();
          callback.onComplete();
    }
    protected abstract void run();
}
//usage
class PrintHi extends Command {
    protected PrintHi(WhenDone callback){
        super(callback);
    }

    protected void run(){
        System.out.println("Hi, ");
    }
}

class PrintWorld implements WhenDone {
    public void onComplete(){
        System.out.println("world!");
    }
}
//somewhere
new PrintHi(new PrintWorld()).execute();

使用的例子不是来自现实生活。也许，您应该通过创建CommandManager来分离创建和调用执行。

Java：使用onComplete回调简单实现Command模式？

1 个答案: