设计模式01创建型模式-建造者模式(BuildPattern)

public interface RobotPlan {
    
    public void setHead(String head);
    
    public void setTorso(String torso);
    
    public void setArms(String arms);
    
    public void setLegs(String legs);
}

public class Robot implements RobotPlan {
    private String head;
    private String torso;
    private String arms;
    private String legs;

    @Override
    public void setHead(String head) { this.head = head; }
    
    public String getHead() { return head; }

    @Override
    public void setTorso(String torso) { this.torso = torso; }
    
    public String getTorso() { return torso; }
    
    @Override
    public void setArms(String arms) { this.arms = arms; }

    public String getArms() { return arms; }
    
    @Override
    public void setLegs(String legs) { this.legs = legs; }
    
    public String getLegs() { return legs; }
}

public interface RobotBuilder {
    
    public void buildHead();
    
    public void buildTorso();
    
    public void buildArms();
    
    public void buildLegs();
    
    public Robot getRobot();
}

/* 将robot各子部件固化到builder中 */
public class OldStyleRobotBuilder implements RobotBuilder {

    private Robot robot;
    
    public OldStyleRobotBuilder(){
        robot = new Robot();
    }
    
    @Override
    public void buildHead() {
        robot.setHead("Tin Head");
    }

    @Override
    public void buildTorso() {
        robot.setTorso("Tin Torso");
    }

    @Override
    public void buildArms() {
        robot.setArms("Blowtorch Arms");
    }

    @Override
    public void buildLegs() {
        robot.setLegs("Roller Legs");
    }

    @Override
    public Robot getRobot() {
        return robot;
    }

}

/* 指导RobotBuilder构建Robot*/
public class RobotEngineer {
    private RobotBuilder robotBuilder;
    
    public RobotEngineer (RobotBuilder robotBuilder){
        this.robotBuilder = robotBuilder;
    }
    
    public void makeRobot(){
        robotBuilder.buildHead();
        robotBuilder.buildTorso();
        robotBuilder.buildArms();
        robotBuilder.buildLegs();
        
        // 另外一种方式是在此处创建Robot, 然后将build构建的结果复制给Robot
    }
    
    public Robot getRobot(){
        return robotBuilder.getRobot();
    }
}

public class RobotBuilderDemo {

    public static void main(String[] args){
        RobotBuilder robotBuilder = new OldStyleRobotBuilder();
        RobotEngineer robotEngineer = new RobotEngineer(robotBuilder);
        robotEngineer.makeRobot();
        
        Robot robot = robotEngineer.getRobot();
        System.out.println("Robot build component:");
        System.out.println("Robot Head: "+robot.getHead());
        System.out.println("Robot Torso: "+robot.getTorso());
        System.out.println("Robot Arms:"+robot.getArms());
        System.out.println("Robot Legs:"+robot.getLegs());
    }
}