package package1;public class Demo12 {public static void main(String[] args) {	javaTeacher javaTeacher=new javaTeacher(20, "张三", 5000);	javaTeacher.work();	/*	 *抽象类不能被实例化	 * Employee employee=new Employee(20, "张三", 5000);	 * */	Leader leader=new Leader(20, "王五", 5000,1000);	//向下转型	leader.work();	Employee emp=new Leader(20, "王五", 5000,1000);	emp.work();}}//抽象类abstract class Employee{	private int number;	private String name;	private double salary;	public Employee(int number,String name,double salary) {		this.name=name;		this.number=number;		this.salary=salary;	}	//抽象方法	public abstract void work();	//可实现的方法	public  void aa() {}  //抽象类中可以有抽象方法也可以有可实现的方法}//一个类继承了抽象类，那么这个类要么实现抽象类中的方法，要么继续抽象下去class Leader extends Employee{	//私有属性	private double allowance;//津贴	public Leader (int number,String name,double salary,double allowance) {		super(number, name, salary);		this.allowance=allowance;	}	@Override	public void work() {		// TODO Auto-generated method stub		System.out.println("培训新员工");		System.out.println("设计课程");	}	/*	 *继续抽象下去的表现	 * public abstract void work() {}	 * */}class javaTeacher extends Employee{	public javaTeacher (int number,String name,double salary) {		super(number, name, salary);	}	@Override	public void work() {		// TODO Auto-generated method stub		System.out.println("上java课程");	}}