关于状态的OO编程

Question

这是我教授的oo编程作业。但我发现婚姻状况可以是Person类中的一个变量，我如何用两个类来实现这一点？

假设人们可以有婚姻状况：单身、已婚、寡妇、离婚。创建一个处理人们婚姻状况的状态OODP(即Java、JavaScript、C++、Python或Ruby(。你将至少有两个类别：个人和婚姻状态。请确保遵循以下规则：单身->已婚->离婚|寡妇离婚->已婚寡妇->已婚创建一个客户端类来测试您的程序。确保您测试婚姻状况的有效和无效变更
任务页面

---

这些是我的代码：

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

此处：

String maritalstatus;

这可能不是你的教授想要的。婚姻状况的意义在于：只有一套固定的价值观。

正确的表达方式是在java中使用枚举，比如：

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

然后，您可以通过创建一个状态机来进一步增强这一点，该状态机实现规则，例如：当您是SINGLE和doMarry()时，您的新状态应该是MARRIED。

Answer 2

复制之前和过去

这个解决方案可能不是你的教授想要的。在这种情况下可以使用多种其他解决方案。

在下面的解决方案中，我假设您只能使用2个类

可能的解决方案

您的Person应该有一个类型为MaritalState的字段。这个MaritalState跟踪Person的状态，所以它不必自己做。

以下只是快速而肮脏的，旨在向您展示聚合背后的想法。

个人

Person现在将依赖于MaritalState的所有逻辑委托给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

处于Person的逻辑现在处于Martiral状态。我扩展了一些像isSingle()这样的功能，使代码更可读。

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;
}
}