Student.java檔案

public class Student {
    public void study()
    {
        System.out.println("好好學習，天天向上");
    }

}

Teacher.java檔案

public class Teacher {
    public Student getStudent()
    {
        Student s=new Student();
        return s;
    }
}

Test.java檔案

//需求:通過Teacher得到Student物件，然後呼叫Student類的方法
//如果方法的返回值是類名:其實返回的該類的物件
public class Test {
    public static void main(String[] args) {
        Teacher t=new Teacher();
        Student s=t.getStudent();
        s.study();
    }