class person {
   
    public int id;
    public String name;
    public void setid(int id) {this.id = id;}
    public void setname(String name){this.name = name;}
    public String getname(){return name;}
    public int getid(){return id;}
        
    }
   
class puplic extends person {
   
    public String school;
    public String setschool(String school){return school;}
    public String getschool(){return school;}
    public String getinfo() {
        return "id+" +getname() + getid() + school;
   
    }
}
   
    public class jicheng {
        
        public static void main(String agrs[]){
        person w = new person();
        puplic q = new puplic();
        person.setname("dasha");
        person.setid(123456);
        puplic.setschool("lande zhiku");
        System.out.println(puplic.getinfo());
            }
        
        }

w.setname("dasha");
        w.setid(123456);
        q.setschool("lande zhiku");
        System.out.println(q.getinfo());

没有加static怎么可能通过类名直接调用

person下的方法没有用静态修饰，或者创建一份对对象再调用。 person p=newperson();