根据UML写出对应的代码，为给定的类编写相应的无参数的构造方法和带参数的构造方法，以及修改和访问每个属性的方法，并在main方法中进行实例化。 ————————— | Student | |————————| |-name:String | |-age:int | |-sex: char | ————————

以下是对应的代码：

public class Student {
    private String name;
    private int age;
    private char sex;

    public Student() {}

    public Student(String name, int age, char sex) {
        this.name = name;
        this.age = age;
        this.sex = sex;
    }

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

    public void setAge(int age) {
        this.age = age;
    }

    public void setSex(char sex) {
        this.sex = sex;
    }

    public String getName() {
        return name;
    }

    public int getAge() {
        return age;
    }

    public char getSex() {
        return sex;
    }

    public static void main(String[] args) {
        Student student1 = new Student();
        Student student2 = new Student("John", 18, 'M');
        System.out.println("Student 1: " + student1.getName() + ", " + student1.getAge() + ", " + student1.getSex());
        System.out.println("Student 2: " + student2.getName() + ", " + student2.getAge() + ", " + student2.getSex());
        student1.setName("Jane");
        student1.setAge(20);
        student1.setSex('F');
        System.out.println("Student 1 after modification: " + student1.getName() + ", " + student1.getAge() + ", " + student1.getSex());
    }
}

在main方法中，我们实例化了两个学生对象，一个使用无参数构造方法，另一个使用带参数构造方法。然后，我们通过修改和访问每个属性的方法来修改学生对象的属性，并在控制台上打印出学生对象的属性值。