C04 建造者示例（二）链式调用

最新推荐文章于 2022-12-12 20:41:59 发布

乌鲁木齐001号程序员

最新推荐文章于 2022-12-12 20:41:59 发布

阅读量145

点赞数

CC 4.0 BY-SA版权

本文链接：https://blog.youkuaiyun.com/weixin_33669968/article/details/88889564

本文介绍了一种常用的设计模式——建造者模式，并展示了如何通过链式调用简化对象创建过程。以课程信息为例，通过Builder模式，可以灵活地设定对象属性，避免了构造函数参数过多的问题。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

建造者模式的链式调用是一种很常用的使用方式；

类图

建造者模式-链式调用.png

代码

public class Course {

    private String courseName;
    private String courseVideo;
    private String courseArticle;
    private String coursePPT;
    private String courseQA;

    public Course(Builder builder) {
        this.courseName = builder.courseName;
        this.courseVideo = builder.courseVideo;
        this.courseArticle = builder.courseArticle;
        this.coursePPT = builder.coursePPT;
        this.courseQA = builder.courseQA;
    }

    public static class Builder {

        private String courseName;
        private String courseVideo;
        private String courseArticle;
        private String coursePPT;
        private String courseQA;

        public Builder() {}

        public Builder courseName(String val) {
            this.courseName = val;
            return this;
        }

        public Builder courseVideo(String val) {
            this.courseVideo = val;
            return this;
        }

        public Builder courseArticle(String val) {
            this.courseArticle = val;
            return this;
        }

        public Builder coursePPT(String val) {
            this.coursePPT = val;
            return this;
        }

        public Builder courseQA(String val) {
            this.courseQA = val;
            return this;
        }

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

    }

    @Override
    public String toString() {
        return "Course{" +
                "courseName='" + courseName + '\'' +
                ", courseVideo='" + courseVideo + '\'' +
                ", courseArticle='" + courseArticle + '\'' +
                ", coursePPT='" + coursePPT + '\'' +
                ", courseQA='" + courseQA + '\'' +
                '}';
    }

}

客户端

public class Test {

    public static void main(String[] args) {
        Course course = new Course.Builder()
                .courseName("Java设计模式精讲")
                .courseVideo("Java设计模式精讲视频")
                .coursePPT("Java设计模式精讲PPT")
                .build();
        System.out.println(course);
    }

}

输出：