创建型模式-构建者模式

1.构建者模式

灵活地构建多个成员变量的复杂对象。

2.示例

public class Human
{
    private String head;
    private String body;
    private String foot;

    public Human(Builder builder)
    {
        this.head = builder.head;
        this.body = builder.body;
        this.foot = builder.foot;
    }

    public String getHead()
    {
        return head;
    }

    public String getBody()
    {
        return body;
    }

    public String getFoot()
    {
        return foot;
    }

    @Override
    public String toString()
    {
        return "Human:"+this.head+"-"+this.body+"-"+this.foot;
    }

    public static class Builder{
        private String head;
        private String body;
        private String foot;

        public Builder setHead(String head)
        {
            this.head = head;
            return this;
        }

        public Builder setBody(String body)
        {
            this.body = body;
            return this;
        }

        public Builder setFoot(String foot)
        {
            this.foot = foot;
            return this;
        }

        public Human build()
        {
            return new Human(this);
        }
    }
}

Human human = new Human.Builder().setBody("身体").setHead("头").setFoot("脚").build();
System.out.println(human);

直接使用具体Builder和具体的产品直接进行构建组建自己。而且在构建完部件以后，直接返回该Builder对象，方便链式调用，也达到了一句话创建复杂对象的过程。