2.编写一个类Student，该类拥有属性：校名、学号、性别、出生日期。方法包含设置姓名和成绩(setName()，setScore())，再编写Student类的子类Undergraduate(大学

当然可以。首先，我们创建一个名为`Student`的基本类，用于存储学生的基本信息：

public class Student {
    private String schoolName;
    private int studentID;
    private String gender;
    private Date birthDate;
    // 默认构造函数
    public Student(String schoolName) {
        this.schoolName = schoolName;
    }

    // 属性访问器和设置器
    public void setName(String name) {
        this.name = name;
    }
    
    public void setScore(int score) {
        // 这里假设score是一个整数范围内的值，具体实现可能会更复杂
        if (score >= 0 && score <= 100) {
            this.score = score;
        } else {
            throw new IllegalArgumentException("Score must be between 0 and 100.");
        }
    }

    // getter methods for accessing the properties
    public String getSchoolName() {
        return schoolName;
    }
    
    public int getStudentID() {
        return studentID;
    }
    
    public String getGender() {
        return gender;
    }
    
    public Date getBirthDate() {
        return birthDate;
    }

    // 省略setters for gender and birthDate for brevity
}

接着，我们创建一个名为`Undergraduate`的子类，它继承自`Student`并可能添加特定于大学生的功能：

public class Undergraduate extends Student {
    private String major; // 专业
    private double gpa;   // 平均绩点

    // 子类特有的构造函数，需要包含基本类的所有参数
    public Undergraduate(String schoolName, String major, int studentID, String gender, Date birthDate) {
        super(schoolName);
        this.major = major;
        this.studentID = studentID;
        this.gender = gender;
        this.birthDate = birthDate;
    }

    // 如果有特殊的设置方法，例如设置平均绩点
    public void setGPA(double gpa) {
        if (gpa >= 0.0 && gpa <= 4.0) {
            this.gpa = gpa;
        } else {
            throw new IllegalArgumentException("GPA must be between 0.0 and 4.0.");
        }
    }

    // getter method for major
    public String getMajor() {
        return major;
    }

    // getter method for GPA
    public double getGPA() {
        return gpa;
    }
}