面向狀態的OO編程

Question

這是我教授的oo編程任務。 但是我發現婚姻狀況在Person類中可以是一個變量，如何通過兩個類來實現？

假設人們可以擁有婚姻狀況：單身，已婚，寡婦，離婚。 創建一個狀態OODP（即Java，JavaScript，C ++，Python或Ruby）來處理人們的婚姻狀況。 您將至少有兩節課：人格和婚姻狀態。 確保遵循以下規則：單身->已婚->離婚| 寡婦離婚->已婚寡婦->已婚創建一個Client類來測試您的程序。 確保測試婚姻狀況的有效和無效變化。
作業頁面

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這些是我的代碼：

public class AssignmentOOP {
    public static void main(String[] args) {
        Person p1 = new Person("p1");
        Person p2 = new Person("p2");
        Person p3 = new Person("p3");
        p1.PrintMaritalStatus();
        p2.PrintMaritalStatus();
        p3.PrintMaritalStatus();
        p1.GetMarried(p2);
        p1.GetMarried(p3);
        p2.Died();
        p1.GetMarried(p3);
    }
}

class Person {
    String maritalstatus;
    boolean mateIsAlive;
    Person mate;
    String name;

    Person(String name1) {
        maritalstatus = "single";
        mate = null;
        name = name1;
    }

    void GetMarried(Person mate) {
        if(this.maritalstatus.equals("married")|| mate.maritalstatus.equals("married"))
        {
            System.out.println("Marital status error! At least one of you are married");
            return;
        } else {
            this.maritalstatus = "married";
            this.mate = mate;
            mate.maritalstatus = "married";
            mate.mate = this;
            System.out.println("Congratulations!!! " + this.name + " and " + mate.name + " are married!");
        }
    }

    void GetDivorced(Person mate) {
        if(this.maritalstatus.equals("married") && this.mate == mate) {
            maritalstatus = "divorced";
            System.out.println(this.name+" and "+mate.name+" are getting divorced.");
        }else if(this.maritalstatus.equals("single")) {
            System.out.println("You are not married and you cannot get divorced before getting married");
        }else if(maritalstatus.equals("widow")) {
            System.out.println("Your marital status is widow, you cannot get divorced.");
        }
    }

    void Died() {
        this.maritalstatus = "dead";
        this.mate.maritalstatus = "widow";
        System.out.println("Sorry for your loss, " + this.mate.name + " marital status is widow.");
    }

    void PrintMaritalStatus() {
        System.out.println(this.name + " marital status is " + this.maritalstatus);
    }
}

Answer 1

這里：

String maritalstatus;

那可能不是您的教授想要的。 該婚姻狀況的重點是：只有一組固定的值。

表達的正確方法是在Java中使用枚舉 ，例如：

public enum MaritalStatus { SINGLE, MARRIED, ... } 

然后，您可以通過創建執行規則的狀態機來進一步增強此功能，例如：當您為SINGLE時，以及doMarry() ，之后應將您的新狀態doMarry() 。

Answer 2

復制和過去之前

該解決方案可能不是您的教授想要的。 在這種情況下，可以使用多種其他解決方案。

在以下解決方案中， 我假設您只能使用2個類！

可能的解決方案

您的Person應具有MaritalState類型的MaritalState 。 此MaritalState跟蹤一個Person的狀態，因此不必自己執行。

以下內容既快速又骯臟 ，目的是向您展示聚合背后的想法。

人

現在，“ Person將所有取決於“ MaritalState的邏輯委托給“ MatrialState

public class Person {

  MaritalState maritalState;
  Person mate;
  String name;

  Person(String name1) {
    maritalState = new MaritalState();
    mate = null;
    name = name1;
  }

  void GetMarried(Person mate) {
    maritalState.marry(this, mate);
  }

  void GetDivorced(Person mate) {
    maritalState.divorce(this, mate);
  }

  void Died() {
    maritalState.die(this);
  }

  void PrintMaritalStatus() {
    System.out.println(this.name + " maritalState status is " + this.maritalState.get());
  }

  public boolean isMarried() {
    return maritalState.isMarried(maritalState);
  }

  public boolean isSingle() {
    return maritalState.isSingle(maritalState);
  }

  public boolean isWidow() {
    return maritalState.isWidow(maritalState);
  }
}

MaritalState

這在邏輯Person現在處於Martiral狀態。 我擴展了isSingle()類的功能，以使代碼更具可讀性。

public class MaritalState {

  private static final String MARRIED = "married";
  private static final String SINGLE = "single";
  private static final String WIDOW = "widow";

  private String state;

  private MaritalState(String state) {
    this.state = state;
  }

  public MaritalState() {
    this.state = "single";
  }

  void marry(Person person, Person mate) {
    if (person.isMarried() || mate.isMarried()) {
      System.out.println("MaritalState status error! At least one of you are married");
    } else {
      person.maritalState = new MaritalState(MARRIED);
      person.mate = mate;
      mate.maritalState = new MaritalState(MARRIED);
      mate.mate = person;
      System.out.println("Congratulations!!! " + person.name + " and " + mate.name + " are married!");
    }
  }

  void divorce(Person person, Person mate) {
    if (person.isMarried() && person.mate == mate) {
      person.maritalState = new MaritalState("divorced");
      System.out.println(person.name + " and " + mate.name + " are getting divorced.");
    } else if (person.isSingle()) {
      System.out.println("You are not married and you cannot get divorced before getting married");
    } else if (person.isWidow()) {
      System.out.println("Your maritalState status is widow, you cannot get divorced.");
    }
  }

  void die(Person person) {
    person.maritalState = new MaritalState("dead");
    person.mate.maritalState = new MaritalState("widow");
    System.out.println("Sorry for your loss, " + person.mate.name + " maritalState status is widow.");
  }

  public boolean isMarried(MaritalState maritalState) {
    return maritalState.state.equals(MARRIED);
  }

  public boolean isSingle(MaritalState maritalState) {
    return maritalState.state.equals(SINGLE);
  }

  public boolean isWidow(MaritalState maritalState) {
    return maritalState.state.equals(WIDOW);
  }

  public String get() {
    return state;
  }
}