class Employee{
private String name;
private int age;
private float salary;
private Manager m;

public Employee(){
  this.name=null;
  this.age=0;
  this.salary=0.0f;
  this.m=null;
}
public Employee(String name,int age,float salary){
  this.setName(name);
  this.setAge(age);
  this.setSalary(salary);
}

public String say(){
  return "姓名："+this.getName()+" 年龄："+this.getAge()+" 薪水："+this.getSalary();
}

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

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

public void setSalary(float salary){
  this.salary=salary;
}
public float getSalary(){
  return this.salary;
}

public void setM(Manager m){
  this.m=m;
}
public Manager getM(){
  return this.m;
}
}

class Manager extends Employee{
private int num;

public Manager(){
}
public Manager(String name,int age,float salary,int num){
  super(name,age,salary);
  this.setNum(num);
}

public String say(){
  return super.say()+" 管理人员数："+this.getNum();
}

public void setNum(int num){
  this.num=num;
}
public int getNum(){
  return this.num;
}
}
class EmployeeDemo
{
public static void main(String[] args){
Employee e=new Employee("张三",25,5200);
e.say();
Manager m=new Manager("李四",35,12000,30);
m.say();
System.out.println(e.say());
System.out.println(m.say());

}

}

你这写的有点乱啊，你的无参构造方法里面的代码没有意义啊，而且直接this.成员变量就可以了，不用再调用方法了，下面看不下去了.........