java - 使用匿名类实例化了一个抽象类之后，如何重写其中的抽象方法并调用？

Question

public abstract class Rhythm {

    /**
     * @return duration between {@linkplain Note} in milliseconds
     */
    public abstract long getDuration();

    public void perform() {
        long duration = getDuration();
        try {
            Thread.sleep(duration);
        } catch (InterruptedException ie) {
            Thread.currentThread().interrupt();
            throw new RuntimeException(ie);
        }
    }
}

--------------------------------------------------------------------

@Override public void play(Rhythm rhythm, Note note, NoteCallback noteCallback){
    rhythm.getDuration();//想在这里重写getDuration方法，如何做到？
    rhythm.perform();
    note.getNoteValue();
    noteCallback.notePlayed(note);
}

--------------------------------------------------------------------

//重写成如下形式
  @Override public long getDuration(){
      return (expectedMs);
   }

代码附上。在play() 方法中如何直接重写Rhythm类中的抽象方法getDuration()呢？ 创建rhythm对象是可以用匿名类的方法实例化的，那是实例化之后 想调用一个重写的getDuration()方法，有什么办法么？在不引入子类继承的前提下。

Answer 1

Java can’t do this, but it can use internal classes to achieve this requirement in disguise

public abstract class Rhythm {

    /**
     * @return duration between {@linkplain Note} in milliseconds
     */
    public abstract long getDuration();
    
    public abstract class InnderClass {
        public abstract long getDuration();
    }

    private InnderClass innderClass;

    public Rhythm() {
        innderClass = new InnderClass() {
            @Override
            public long getDuration() {
                return Rhythm.this.getDuration();
            }
        };
    }

    public void setInnderClass(InnderClass innderClass) {
        this.innderClass = innderClass;
    }

    public void perform() {
        long duration = innderClass.getDuration();
        try {
            Thread.sleep(duration);
        } catch (InterruptedException ie) {
            Thread.currentThread().interrupt();
            throw new RuntimeException(ie);
        }
    }
}

@Override public void play(Rhythm rhythm, Note note, NoteCallback noteCallback){
        //rhythm.getDuration();//想在这里重写getDuration方法，如何做到？
        rhythm.setInnderClass(rhythm.new InnderClass() {
            
            @Override
            public long getDuration() {
                // TODO 把实现放到这里
                return 0;
            }
        });
        rhythm.perform();
        note.getNoteValue();
        noteCallback.notePlayed(note);
    }

Answer 2

Can’t do it? If it can be done in Java, wouldn’t it be a dynamic language?