JAVA 教程

				// Employee.java
				// 抽象类Employee
				
				public abstract class Employee {
				   private String firstName;
				   private String lastName;
				
				   // 构造函数
				   public Employee( String first, String last )
				   {
				      firstName = first;
				      lastName = last;
				   }
				   
				   // 返回姓
				   public String getFirstName() { return firstName; }
				
				   // 返回名
				   public String getLastName() { return lastName; }
				
				   public String toString()
				      { return firstName + ' ' + lastName; }
				
				   // Employee抽象方法earnings();
				   //将被其每个子类以实例继承 
				   public abstract double earnings(); 
				}