简单工厂模式

工厂类生产output实例

public class OutputFactory {public Output getOutput(){return new Printer();}}

Computer类，可以利用工厂得到output实例

public class Computer {private Output out;public Computer(Output out){this.out = out;}public void keyIn(String msg){out.getData(msg);}public void print(){out.out();}public static void main(String args[]){OutputFactory of = new OutputFactory();Computer computer = new Computer(of.getOutput());computer.keyIn("output success");computer.print();}}

Output规范接口

public interface Output {public void out();public void getData(String msg);}

Output实现类

public class Printer implements Output{String msg;public void out() {System.out.println("the output: " + msg);}public void getData(String msg) { this.msg = msg;}}