Java面向对象编程多个类实例

时间:2018-03-20 13:48:56

标签: java class interface object-oriented-analysis

由于我自己研究了编程,我认为我应该开始创建适当的类和变量,但我似乎没有得到它。

我已经读过,首先我需要一个interface,所以我让我看起来像这样:

public interface PitchInterface {
    void setOccuranceTime(float occuranceTime);
    float getOccuranceTime();
    void setPitch(float pitch);
    float getPitch();
}

其次,我创建了一个实现interface

的类
public class Pitch implements PitchInterface{

    float occuranceTime;
    float pitch;

    @Override
    public void setOccuranceTime(float occuranceTime) {
        this.occuranceTime = occuranceTime;
    }

    @Override
    public float getOccuranceTime() {
        return occuranceTime;
    }

    @Override
    public void setPitch(float pitch) {
        this.pitch = pitch;
    }

    @Override
    public float getPitch() {
        return pitch;
    }
}

现在我需要为Pitch提供值,这就是我现在被困住的地方:

public class Foo {

    Pitch pitch = new Pitch();
    String[] pitches;
    List<Pitch> listOfPitches = new ArrayList<Pitch>();
    List<String> wordsList = new ArrayList<String>();

public List<Pitch> getListOfPitches(){
    getPitches();
    for (String pitchString: pitches) {
        makeListOfPitches(pitch, pitchString);
    }
    return listOfPitches;
}

public void makeListOfPitches(Pitch pitch, String pitchString){
    pitch.setPitch(getPitchesInfo(pitchString, 0));
    pitch.setOccuranceTime(getPitchesInfo(pitchString, 1));
    listOfPitches.add(pitch);
}

    public List<String> getWordsList(){
        //To-do make words out of Pitches and add them to list
        return wordsList;
    }



    public String[] getPitches() {
        pitches = pitchesRaw.split("\\r?\\n");
        return pitches;
    }

    private float getPitchesInfo(String pitch, int position){
        String[] frequencyAndTime = pitch.split("\\:");
        if(position == 0){
            return Float.parseFloat(frequencyAndTime[0].replace(',', '.'));
        }
        if(position == 1){
            return Float.parseFloat(frequencyAndTime[1].replace(',', '.'));
        }
        else return 0;
    }

    String pitchesRaw = "0,14:23281,61\n" +
            "0,23:53,65\n" +
            "0,37:72,53\n" +
            "0,56:86,09\n" +
            "0,60:88,58\n" +
            "0,65:87,45\n" +
            "0,70:87,11\n" +
            "0,74:89,56\n" +
            "0,79:96,22\n" +
            "0,84:23288,24\n" +
            "0,88:103,92\n" +
            "0,93:107,46\n" +
            "0,98:108,02\n" +
            "1,02:107,51\n" +
            "1,07:104,92\n" +
            "1,11:105,94\n" +
            "1,16:106,40\n";
    }

最后从Main类初始化它:

public static void main(String[] args) {
    Foo listOfWordsAndPithes = new Foo();
    List<Pitch> list = listOfWordsAndPithes.getListOfPitches();
    for (Pitch pitch: list) {
        System.out.println(pitch.getPitch());
    }
}
  • 首先,如果我在循环中打印出所有pitches,如上所示,我将下面显示的值作为输出。但我想要的是每个音高具有与pitchesRaw

    不同的值

    106.4 106.4 106.4 106.4 106.4 106.4 106.4 106.4 106.4 106.4 106.4 106.4 106.4 106.4 106.4 106.4 106.4

  • 其次,如果我需要通过将多个words list添加到一个列表中(例如将6个不同的Pitch添加到1个列表中)而使Pitches超出节距,然后添加{{1}另一个列表,它将是新列表的第一个元素。那么我是否需要制作另一个名为Pitches的{​​{1}},并在那里定义哪个词以及如何设置/获取它?

  • 第三,我从评论中读到,不需要使用Interface。我何时才知道使用界面是否可以?何时没有?

1 个答案:

答案 0 :(得分:1)

要回答问题的最后部分,在这里使用接口既不好也不坏,您实际上是为您的getter和setter创建一个接口,是否必要取决于您希望如何使用该接口。在您的情况下,它看起来没有必要。看看Java Interface Usage Guidelines -- Are getters and setters in an interface bad?

关于你的第二个问题,你可能也不需要一个单独的类来实例化音高列表,word实际上有意义并且会在别处被实例化为对象吗?如果您只想要一个列表,只需执行上面List<Pitch> word = new ArrayList<Pitch>();所做的操作,只需将间距添加到列表中即可。