Person.java源程序清单public class Personprivate String name;private int age;public Person()name = ;age = 0;public Person(String name,int age)this.name=name;if(age0)age = 0;this.age=age;public void setName(String name)this.name=name;public String getName()return name;public void setAge(int age)if(age0)age=0;this.age=age;public int getAge()return age;public void display()System.out.println(姓名: + name + t年龄： + age);Student.java源程序清单public class Student extends Personprivate String schoolName;Student()schoolName = ;Student(String name,int age,String schoolName)super(name,age);this.schoolName = schoolName;public void setSchoolName(String schoolName)this.schoolName = schoolName;public String getSchoolName()return schoolName;public void display()super.display();System.out.println(学校名称： + schoolName);Worker.java源程序清单public class Worker extends Personprivate Long yield;public Worker()yield = new Long(0);public Worker(String name,int age,Long yield)super(name,age);this.yield = yield;public void setYield(Long yield)this.yield = yield;public Long getYield()return yield;public void display()super.display();System.out.println(产量：+yield.longValue();Viewer.java源程序清单public class Viewer public void view(Person p) p.display(); Test.java源程序清单public class Test /含有main()方法的主类public static void main(String args)Student s = new Student(张三,24,我的学堂); /定义Student类变量并实例化Worker w = new Worker(Jone,40,new Long(1005); /定义Worker类变量并实例化Viewer v = new Viewer();v.view(s);/调用Student对象的实例方法v.view(w); /调用Worker对象的实例方法