/** * 创建一个学生类，有四个属性（姓名、学号、年级、性别） * 给每个属性赋予getter、setter方法 * 学生类有学习、考试、打游戏的方法（方法输出随便写） * 创建两个学生类实例化对象，第一个调用无参构造方法，然后通过getter\setter方法给赋予属性值 * 第二个，调用全参构造方法，给每一个属性都初始化。 * */

好的，下面是实现代码：

public class Student {
    private String name;
    private String number;
    private String grade;
    private String gender;

    public Student() {}

    public Student(String name, String number, String grade, String gender) {
        this.name = name;
        this.number = number;
        this.grade = grade;
        this.gender = gender;
    }

    // getter and setter methods
    public String getName() {
        return name;
    }

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

    public String getNumber() {
        return number;
    }

    public void setNumber(String number) {
        this.number = number;
    }

    public String getGrade() {
        return grade;
    }

    public void setGrade(String grade) {
        this.grade = grade;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    // study, exam, and play methods
    public void study() {
        System.out.println(name + " is studying.");
    }

    public void exam() {
        System.out.println(name + " is taking an exam.");
    }

    public void play() {
        System.out.println(name + " is playing a game.");
    }
}

// main method for testing
public static void main(String[] args) {
    Student stu1 = new Student();
    stu1.setName("Tom");
    stu1.setNumber("001");
    stu1.setGrade("Grade 10");
    stu1.setGender("Male");

    Student stu2 = new Student("Lisa", "002", "Grade 11", "Female");

    stu1.study();
    stu1.exam();
    stu1.play();

    stu2.study();
    stu2.exam();
    stu2.play();
}

希望能够帮助到你。