用java设计一个soudable，该接口具有发声功能，还能调节音量大小，soundable接口可由三个设备实现，分别是收音机radio，随身听walman，手机Mobliephone

在Java中，你可以设计一个名为`Soundable`的接口，并添加`setVolume(int volume)`方法用于设置音量，同时让三个设备类`Radio`, `Walkman`, 和 `MobilePhone` 实现这个接口。下面是相关的代码实现：

// Soundable 接口
public interface Soundable {
    // 设置音量
    void setVolume(int volume);
    
    // 抽象方法，播放声音
    abstract void playSound();
}

// Radio 类实现 Soundable 接口
public class Radio implements Soundable {
    private int volume;

    @Override
    public void setVolume(int volume) {
        this.volume = volume;
        System.out.println("Radio set to volume: " + volume);
    }

    @Override
    public void playSound() {
        System.out.println("Radio is playing with volume: " + volume);
    }
}

// Walkman 类实现 Soundable 接口
public class Walkman implements Soundable {
    private int volume;

    @Override
    public void setVolume(int volume) {
        this.volume = volume;
        System.out.println("Walkman set to volume: " + volume);
    }

    @Override
    public void playSound() {
        System.out.println("Walkman is playing with volume: " + volume);
    }
}

// MobilePhone 类实现 Soundable 接口
public class MobilePhone implements Soundable {
    private int volume;

    @Override
    public void setVolume(int volume) {
        this.volume = volume;
        System.out.println("MobilePhone set to volume: " + volume);
    }

    @Override
    public void playSound() {
        System.out.println("MobilePhone is playing with volume: " + volume);
    }
}

// 主程序
public class Main {
    public static void main(String[] args) {
        Soundable radio = new Radio();
        radio.setVolume(50); // 设置音量
        radio.playSound();

        Soundable walkman = new Walkman();
        walkman.setVolume(75);
        walkman.playSound();

        Soundable mobilePhone = new MobilePhone();
        mobilePhone.setVolume(90);
        mobilePhone.playSound();
    }
}