HashSet编程小案例，控制生日和姓名。重写HashCode

最新推荐文章于 2024-10-19 10:18:15 发布

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最新推荐文章于 2024-10-19 10:18:15 发布

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分类专栏：韩顺平java习题文章标签： java 开发语言

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本文介绍了如何在Java中使用HashSet存储Employee对象，确保当name和birthday完全相同时，不会将重复员工添加到集合。通过重写equals和hashCode方法来判断员工是否相等。

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Java编程：

定义员工Employee类，该类包含：private成员属性name，sal，birthday(MyDate类型)，

其中birthday为MyDate类型(属性包括：year，month，day)，

要求：

1.创建3个Employee放入HashSet中；

当name和birthday的值相同时，认为是相员工，不能添加到HashSet集合中。

 @SuppressWarnings({"all"})
    public static void main(String[] args) {
        HashSet hashset = new HashSet();
        Employeeday19 employee1 =new Employeeday19("Tom",11000,new MyDate(2010,12,12));
        Employeeday19 employee2 =new Employeeday19("Simth",18000,new MyDate(2011,12,18));
        Employeeday19 employee3 =new Employeeday19("Jenny",31000,new MyDate(2012,12,03));
        hashset.add(employee1);
        hashset.add(employee2);
        hashset.add(employee3);

        System.out.println(hashset);

        Employeeday19 employee4 =new Employeeday19("Jenny",31000,new MyDate(2012,12,03));
        hashset.add(employee4);

        System.out.println("=======二次打印=======");
        System.out.println(hashset);

    }
}

class MyDate {
    private int year;
    private int month;
    private int day;

    @Override
    public String toString() {
        return " year=" + year +
                ", month=" + month +
                ", day=" + day ;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        MyDate myDate = (MyDate) o;
        return year == myDate.year && month == myDate.month && day == myDate.day;
    }

    @Override
    public int hashCode() {
        return Objects.hash(year, month, day);
    }

    public int getYear() {
        return year;
    }

    public void setYear(int year) {
        this.year = year;
    }

    public int getMonth() {
        return month;
    }

    public void setMonth(int month) {
        this.month = month;
    }

    public int getDay() {
        return day;
    }

    public void setDay(int day) {
        this.day = day;
    }

    public MyDate(int year, int month, int day) {
        this.year = year;
        this.month = month;
        this.day = day;
    }
}

class Employeeday19 {
    private String name;
    private double sal;
    private MyDate birthday;

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Employeeday19 that = (Employeeday19) o;
        return Objects.equals(name, that.name);
    }

    @Override
    public int hashCode() {
        return Objects.hash(name);
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getSal() {
        return sal;
    }

    public void setSal(double sal) {
        this.sal = sal;
    }

    public MyDate getBirthday() {
        return birthday;
    }

    public void setBirthday(MyDate birthday) {
        this.birthday = birthday;
    }

    public Employeeday19(String name, double sal, MyDate birthday) {
        this.name = name;
        this.sal = sal;
        this.birthday = birthday;
    }

    @Override
    public String toString() {
        return "name='" + name + '\'' +
                ", sal=" + sal +
                ", birthday：" + birthday +"\n";
    }