父类

package testP.test;

public class Person {
    private String name;
    protected String age;
    protected String sex;
    String how;

    public Person() {
        System.out.print("Person");
    }
    Person(String name) {
        System.out.print(name);
    }


    private String getName() {
        return name;

    }

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

    public String get() {
        return name;
    }
}

子类

package testP.test;

public class son extends Person {

    String old;
    public son(String age, String name) {
//      super(); /调用父类的默认构造函数
        super(name); // 调用父类的默认构造函数
        System.out.print("name=" + name);
        System.out.print("age=" + age);
    }
    son(String name) {
        this("name", "age"); //调用自己的默认构造函数
        System.out.print(name);

    }
     public static void main(String[] args) {
         son s = new son("test");
         System.out.print(s.age); // age是父类Person的属性字段
         System.out.print(s.sex); // age是父类Person的属性字段
         System.out.print(s.how); // how是父类Person的属性字段
         System.out.print(s.get()); // get()是父类Person的方法
         System.out.print(s.old); // old 是son类的属性

        }
}