设计模式:建造者模式

public class Director {    private ComputerBuilder computerBuilder;    public void setComputerBuilder(ComputerBuilder computerBuilder) { this.computerBuilder = computerBuilder; }    public ComputerBuilder getComputerBuilder() { return this.computerBuilder; }    public void createComputer() {        this.computerBuilder.createComputer();;        this.computerBuilder.builderKeyboard();        this.computerBuilder.builderMouse();    }}class Computer {    private String mouse;    private String keyboard;    public void setKeyboard(String keyboard) { this.keyboard = keyboard; }    public void setMouse(String mouse) { this.mouse = mouse; }} abstract class ComputerBuilder {    protected Computer computer;    public Computer getComputer() { return this.computer; }    public void  createComputer() { this.computer = new Computer(); }    public abstract void builderKeyboard();    public abstract void builderMouse();}class MacBookProBuilder extends ComputerBuilder {    @Override    public void builderKeyboard() { super.computer.setKeyboard("mac keyboard"); }    @Override    public void builderMouse() { super.computer.setMouse("mac mouse"); }}class WindowsBuilder extends ComputerBuilder {    @Override    public void builderKeyboard() { super.computer.setKeyboard("windows keyboard");}    @Override    public void builderMouse() { super.computer.setMouse("windows mouse");}}