建造者（Builder）模式的主要模块如下：
1. 建造者接口：负责建造各个组件
2.装配者接口：负责将组件组装成产品
3.产品类：成员变量为各组件对象
4.各个组件类
5. 建造者实现类：实现建造者接口
6.装配者实现类：实现装配者接口
7.客户端调用类
这里以建造超级计算机为例，演示构建者模式原理：
假设计算机由CPU/主板/内存三个部件组成，现在要生产一台陌桑超级计算机，CPU为AMD的CPU，主板为华硕主板，内存为256G容量内存。类关系图如下：
使用建造者模式具体做法：
package net.mosang.builder;
/**
* 具体产品类
* @author heiry
*
*/
public class Computer {
private CPU cpu;
private Mainboard mainboard;
private Memory memory;
public CPU getCpu() {
return cpu;
}
public void setCpu(CPU cpu) {
this.cpu = cpu;
}
public Mainboard getMainboard() {
return mainboard;
}
public void setMainboard(Mainboard mainboard) {
this.mainboard = mainboard;
}
public Memory getMemory() {
return memory;
}
public void setMemory(Memory memory) {
this.memory = memory;
}
}
package net.mosang.builder;
/**
* 构建子组件接口
* @author heiry
*
*/
public interface ComputerBuilder {
public CPU buildCPU();
public Mainboard buildMainboard();
public Memory buildMemory();
}
package net.mosang.builder;
/**
* 装配者接口
* @author heiry
*
*/
public interface ComputerDirector {
public abstract Computer directComputer();
}
package net.mosang.builder;
/**
* 构建者实现类
* 构建陌桑超级计算机部件
* @author wuah
*
*/
public class MosangSuperComputer implements ComputerBuilder {
@Override
public CPU buildCPU() {
System.out.println("陌桑超算使用的是AMD的CPU");
return new CPU("AMD");
}
@Override
public Mainboard buildMainboard() {
System.out.println("陌桑超算使用的是华硕主板");
return new Mainboard("华硕");
}
@Override
public Memory buildMemory() {
System.out.println("陌桑超算使用的是256G内存");
return new Memory(256);
}
}
package net.mosang.builder;
/**
* 装配者实现类：返回具体产品实例
* 陌桑超算由富士康代工装配
* @author heiry
*
*/
public class FoxconnDirector implements ComputerDirector {
private ComputerBuilder builder;
@Override
public Computer directComputer() {
CPU cpu = builder.buildCPU();
Mainboard mainboard = builder.buildMainboard();
Memory memory = builder.buildMemory();
Computer c = new Computer();
c.setCpu(cpu);
c.setMainboard(mainboard);
c.setMemory(memory);
return c;
}
public FoxconnDirector(ComputerBuilder builder) {
super();
this.builder = builder;
}
}
package net.mosang.builder;
/**
* 具体部件类：CPU
* @author heiry
*
*/
public class CPU {
private String brands;
public String getBrands() {
return brands;
}
public void setBrands(String brands) {
this.brands = brands;
}
public CPU(String brands) {
super();
this.brands = brands;
}
}
package net.mosang.builder;
/**
* 具体部件类：内存
* @author heiry
*
*/
public class Memory {
private int capacity;
public Memory(int capacity) {
super();
this.capacity = capacity;
}
public int getCapacity() {
return capacity;
}
public void setCapacity(int capacity) {
this.capacity = capacity;
}
}
package net.mosang.builder;
/**
* 具体部件类：主板
* @author heiry
*
*/
public class Mainboard {
private String producer;
public String getProducer() {
return producer;
}
public void setProducer(String producer) {
this.producer = producer;
}
public Mainboard(String producer) {
super();
this.producer = producer;
}
}
package net.mosang.builder;
/**
* 客户端调用类
* @author heiry
*
*/
public class Client {
public static void main(String[] args) {
MosangSuperComputer msc = new MosangSuperComputer();
FoxconnDirector fd = new FoxconnDirector(msc);
Computer myComputer = fd.directComputer();
System.out.println(myComputer);
}
}
输出结果
陌桑超算使用的是AMD的CPU 陌桑超算使用的是华硕主板 陌桑超算使用的是256G内存 net.mosang.builder.Computer@15db9742
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