1.开发系统时，主体架构使用接口，接口构成系统的骨架
2.这样就可以通过更换接口的实现类来更换系统的实现
public class printerDemo{
public static void main(String[] args) {
ColorPrinter cp = new ColorPrinter("惠普");
BlackPrinter bp = new BlackPrinter("联想");
Teacher teacher = new Teacher("张三",26);
School school = new School();
school.setPrinter(cp);
school.setPrinter(bp);
school.print(school);
school.print(teacher);
bp.print("abc");
cp.print("abc");
}
}
class School implements IInfo{
private Printer p = null;
public void setPrinter(Printer p) {
this.p = p;
}
public void print(IInfo info) {
p.print(info.detail());
}
public String detail() {
return "我是学校";
}
}
interface IInfo{//接口，教师和学校都有的方法
String detail();
}
abstract class Printer{
private String brand;
public String getBrand() {
return brand;
}
public Printer(String brand) {//构造方法
this.brand = brand;
}
public abstract void print(String content) ;
}
class ColorPrinter extends Printer{
public ColorPrinter(String brand) {
super(brand);
}
public void print(String content) {
System.out.println(getBrand()+"彩色打印："+content);
}
}
class BlackPrinter extends Printer{
public BlackPrinter(String brand) {
super(brand);
}
public void print(String content) {
System.out.println(getBrand()+"黑白打印："+content);
}
}
class Teacher implements IInfo{
private String name;
private int age;
public Teacher(String name,int age) {
this.name = name;
this.age = age;
}
public String detail() {
return "我的名字叫"+name+"，年龄是"+age;
}
}