画类图

具体代码实现

//Computer.java
package org.example.design003;

public class Computer {
    public Computer(String CPU, String RAM, String hard, String host) {
        this.CPU = CPU;
        this.RAM = RAM;
        Hard = hard;
        Host = host;
    }

    public Computer(){}

    public String getCPU() {
        return CPU;
    }

    public void setCPU(String CPU) {
        this.CPU = CPU;
    }

    public String getRAM() {
        return RAM;
    }

    public void setRAM(String RAM) {
        this.RAM = RAM;
    }

    public String getHard() {
        return Hard;
    }

    public void setHard(String hard) {
        Hard = hard;
    }

    public String getHost() {
        return Host;
    }

    public void setHost(String host) {
        Host = host;
    }

    private String CPU;
    private String RAM;
    private String Hard;
    private String Host;
}

//ComputerBuilder.java
package org.example.design003;

public abstract class ComputerBuilder {
    protected Computer computer=new Computer();
    public abstract void buildCPU();
    public abstract void buildRAM();
    public abstract void buildHard();
    public abstract void buildHost();

    public Computer getComputer(){
        return computer;
    }
}

//DesktopComputerBuilder.java
package org.example.design003;

public class DesktopComputerBuilder extends ComputerBuilder{

    @Override
    public void buildCPU() {
        computer.setCPU("安装台式机CPU");
    }

    @Override
    public void buildRAM() {
        computer.setRAM("安装台式机内存");
    }

    @Override
    public void buildHard() {
        computer.setHard("安装台式机硬盘");
    }

    @Override
    public void buildHost() {
        computer.setHost("安装台式机主机");
    }
}

//LaptopComputerBuilder.java
package org.example.design003;

public class LaptopComputerBuilder extends ComputerBuilder {
    @Override
    public void buildCPU() {
        computer.setCPU("安装笔记本CPU");
    }

    @Override
    public void buildRAM() {
        computer.setRAM("安装笔记本内存");
    }

    @Override
    public void buildHard() {
        computer.setHard("安装笔记本硬盘");
    }

    @Override
    public void buildHost() {
        computer.setHost("安装笔记本主机");
    }
}

//Director.java
package org.example.design003;

public class Director {
    private ComputerBuilder cb;
    public void setComputerBuilder(ComputerBuilder c)
    {
        cb=c;
    }
    public Computer construct()
    {
        cb.buildCPU();
        cb.buildRAM();
        cb.buildHard();
        cb.buildHost();
        return cb.getComputer();
    }
}

//Main.java
package org.example.design003;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {

        ComputerBuilder cb = null;
        System.out.println("请选择：1、笔记本 2、台式机");
        Scanner input=new Scanner(System.in);
        int i=input.nextInt();
        if(i==1) {
            cb=new LaptopComputerBuilder();
        }else if(i==2) {
            cb=new DesktopComputerBuilder();
        }else {
            System.out.println("输入无效！");
        }
        Director dir=new Director();
        dir.setComputerBuilder(cb);
        Computer computer=dir.construct();
        System.out.println("计算机组成：");
        System.out.println(computer.getCPU());
        System.out.println(computer.getRAM());
        System.out.println(computer.getHard());
        System.out.println(computer.getHost());



    }
}