如何在TournamentIncome类的calculateGradeBonus()方法中访问PlayerIncome的income变量？

需要在TournamentIncome的calculateGradeBonus()方法中使用PlayerIncome的income变量计算奖金，该如何实现？

背景代码结构 #

项目文件结构 #

• Player.java（抽象基类）
• Tax.java（接口）
• PlayerIncome.java（继承Player并实现Tax，包含income实例变量）
• GradeBonus.java（接口）
• TournamentIncome.java（继承Player并实现GradeBonus）
• PlayerTest.java

核心代码片段 #

PlayerIncome类

public class PlayerIncome extends Player implements Tax {

double income;
double tax;

public PlayerIncome(String name, double income) {
    super(name);
    this.income = income;
}

@Override
public void calculateTax() {
    tax = income * (TAX_PERCENT / 100);
}

@Override
void displayDetails() {
    System.out.println("Player Name: " + name);
    System.out.println("Income: " + income);
    System.out.println("Tax: " + tax);
}
}

TournamentIncome类

public class TournamentIncome extends Player implements GradeBonus {

String grade;
int rate;

public TournamentIncome(String name, String grade, int rate) {
    super(name);
    this.grade = grade;
    this.rate = rate;
}

@Override
public void calculateGradeBonus() {
    // 需要访问PlayerIncome的income变量
}

@Override
void displayDetails() {
     
}
}

Player抽象类

public abstract class Player {
String name;

public Player(String name) {
    this.name = name;
}

abstract void displayDetails();
}

解决方案 #

方案1：通过组合注入PlayerIncome实例 #

TournamentIncome与PlayerIncome是平级子类，无法直接访问对方的实例变量。可以在TournamentIncome中持有PlayerIncome的引用，通过构造方法或setter注入后访问income。

修改后的TournamentIncome类：

public class TournamentIncome extends Player implements GradeBonus {

String grade;
int rate;
private PlayerIncome playerIncome;
private double gradeBonus; // 存储计算后的奖金

// 修改构造方法注入PlayerIncome
public TournamentIncome(String name, String grade, int rate, PlayerIncome playerIncome) {
    super(name);
    this.grade = grade;
    this.rate = rate;
    this.playerIncome = playerIncome;
}

@Override
public void calculateGradeBonus() {
    if (playerIncome != null) {
        // 基于PlayerIncome的income计算奖金
        gradeBonus = playerIncome.income * rate / 100;
    }
}

@Override
void displayDetails() {
    System.out.println("Player Name: " + name);
    System.out.println("Grade: " + grade);
    if (playerIncome != null) {
        System.out.println("Base Income: " + playerIncome.income);
        System.out.println("Grade Bonus: " + gradeBonus);
        System.out.println("Total Income: " + (playerIncome.income + gradeBonus));
    }
}
}

方案2：将income提升到父类Player中 #

如果income是所有Player子类的通用属性，直接将其移到抽象基类Player中，子类可直接访问。

修改Player类：

public abstract class Player {
String name;
protected double income; // protected修饰，子类直接访问

public Player(String name, double income) {
    this.name = name;
    this.income = income;
}

abstract void displayDetails();
}

修改PlayerIncome构造方法：

public PlayerIncome(String name, double income) {
    super(name, income); // 调用父类带income的构造方法
}

修改TournamentIncome类：

public class TournamentIncome extends Player implements GradeBonus {

String grade;
int rate;
private double gradeBonus;

public TournamentIncome(String name, String grade, int rate, double income) {
    super(name, income);
    this.grade = grade;
    this.rate = rate;
}

@Override
public void calculateGradeBonus() {
    // 直接使用父类的income计算奖金
    gradeBonus = income * rate / 100;
}

@Override
void displayDetails() {
    System.out.println("Player Name: " + name);
    System.out.println("Grade: " + grade);
    System.out.println("Base Income: " + income);
    System.out.println("Grade Bonus: " + gradeBonus);
    System.out.println("Total Income: " + (income + gradeBonus));
}
}

方案3：给PlayerIncome添加getter方法 #

若不想调整继承结构，给PlayerIncome添加公共getter方法，TournamentIncome持有PlayerIncome实例后通过方法获取income。

修改PlayerIncome类：

public class PlayerIncome extends Player implements Tax {

double income;
double tax;

// ... 原有代码 ...

// 添加income的getter方法
public double getIncome() {
    return income;
}
}

修改TournamentIncome类：

public class TournamentIncome extends Player implements GradeBonus {

String grade;
int rate;
private PlayerIncome playerIncome;
private double gradeBonus;

public TournamentIncome(String name, String grade, int rate, PlayerIncome playerIncome) {
    super(name);
    this.grade = grade;
    this.rate = rate;
    this.playerIncome = playerIncome;
}

@Override
public void calculateGradeBonus() {
    if (playerIncome != null) {
        double baseIncome = playerIncome.getIncome();
        gradeBonus = baseIncome * rate / 100;
    }
}

@Override
void displayDetails() {
    System.out.println("Player Name: " + name);
    System.out.println("Grade: " + grade);
    if (playerIncome != null) {
        System.out.println("Base Income: " + playerIncome.getIncome());
        System.out.println("Grade Bonus: " + gradeBonus);
        System.out.println("Total Income: " + (playerIncome.getIncome() + gradeBonus));
    }
}
}

内容的提问来源于stack exchange，提问作者Pratik Singh