public class Product{
 private String partA;//产品的某个部分，实际开发中可能对应一个类 
 private String partB;//产品的某个部分，实际开发中可能对应一个类 
 private String partC;//产品的某个部分，实际开发中可能对应一个类 
 //构造器及set、get方法
}

//也可以是抽象类
public interface Builder{ 
 public void setPartA(String partA); 
 public void setPartB(String partB); 
 public void setPartC(String partC);
}

public class BuilderImpl implements Builder{
 
 private Product product;
 
 public BuilderImpl(){
 product = new Product();
 }
 
 public void builderPartA(){
 String partA = new String();//模拟工厂方法生产产品的某一个部分
 product.setPartA(partA);
 }
 
 public void builderPartB(){
 String partB = new String();//模拟工厂方法生产产品的某一个部分
 product.setPartB(partB);
 }
 
 public void setPartC(){
 String partC = new String();//模拟工厂方法生产产品的某一个部分
 product.setPartC(partC);
 }
 
 public Product getProduct(){
 return this.product;
 }
}

public class Director{
 private Builder b ;
 
 public Director(Builder newB){
 this.b = newB;
 }
 
 public void createBuilder(Builder b){
 this.b = b;
 }
 
 public Product constructProduct(){
 b.builderPartA();
 b.builderPartB();
 b.builderPartC();
 }
}

public class Demo{
 public static void main(String[] args){
 Builder b = new BuilderImpl();
 Director d = new Director();
 d.createBuilder(b);
 Product p = c.constructProduct();
 }
}