设计模式之建造者模式（builder）

  public class builderPatten {
    private String length;
    private String width;
    private String color;
    private String price;
    private String logo;
    //构造函数，传入的是内部类的一个对象
    private builderPatten(carBuilder builder){
        this.color=builder.color;
        this.length=builder.length;
        this.logo=builder.logo;
        this.price=builder.price;
        this.width=builder.width;
    }
    
    public static class carBuilder{
        private String length;
        private String width;
        private String color;
        private String price;
        private String logo;
       //构建时必须传入的属性。而下面的属性在构造时可以根据需要建造
        public carBuilder(String logo,String price){
            this.logo=logo;
            this.price=price;
        }
        public carBuilder setColor(String color){
            this.color=color;
            return this;
        }
        public carBuilder setWidth(String width){
            this.width=width;
            return this;
        }
        public carBuilder setLength(String length){
            this.length=length;
            return this;
        }
        public builderPatten buid(){
            return new builderPatten(this);
        }
    }

    @Override
    public String toString() {
        return "builderPatten{" +
                "length=‘" + length + ‘\‘‘ +
                ", width=‘" + width + ‘\‘‘ +
                ", color=‘" + color + ‘\‘‘ +
                ", price=‘" + price + ‘\‘‘ +
                ", logo=‘" + logo + ‘\‘‘ +
                ‘}‘;
    }
}

public class patternTest {
    public static void main(String[] args) {
        builderPatten builderPatten=new builderPatten.carBuilder("BMW","1w").setColor("红色").buid();
        System.out.println(builderPatten.toString());
    }
}

结果输出:
builderPatten{length=‘null‘, width=‘null‘, color=‘红色‘, price=‘1w‘, logo=‘BMW‘}