设计模式之建造者模式-java实现

最新推荐文章于 2025-12-07 22:03:20 发布

原创最新推荐文章于 2025-12-07 22:03:20 发布 · 234 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#建造者模式 #builder

杂记专栏收录该内容

14 篇文章

订阅专栏

本文详细介绍了如何在Java中实现建造者模式，通过一个具体的Person类实例，展示了如何使用内部静态类作为构造者，实现对象的优雅构建。该模式特别适用于属性繁多的类，能清晰地处理复杂对象的构建过程。

设计模式建造者模式的java实现类

第一步、创建一个要被构建的类 Persion类并声明属性

package com.chinamsp.mytest.pattern.builder;


class Persion {

    private String name;
    private Integer age;
    private String address;
    private String phone;

}

第二步、创建一个共有的构造者类

package com.chinamsp.mytest.pattern.builder;


class Persion {

    private String name;
    private Integer age;
    private String address;
    private String phone;


    public static class Builder {
       /** 此处的属性和上边的被构造类属性对应 */
        private String name;
        private Integer age;
        private String address;
        private String phone;
       
        /** 赋值各个属性方法 */
        public Builder name(String name) {
            this.name = name;
            return this;
        }

        public Builder age(Integer age) {
            this.age = age;
            return this;
        }

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

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

第三步、在被构造对象中声明有参构造，在构造对象中创建build方法返回被构造对象

package com.chinamsp.mytest.pattern.builder;


class Persion {

    private String name;
    private Integer age;
    private String address;
    private String phone;

  
    public Persion(Builder builder) {
        this.name = builder.name;
        this.age = builder.age;
        this.address = builder.address;
        this.phone = builder.phone;
    }


    public static class Builder {
        private String name;
        private Integer age;
        private String address;
        private String phone;

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

        public Builder age(Integer age) {
            this.age = age;
            return this;
        }

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

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

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

    @Override
    public String toString() {
        return "Persion{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", address='" + address + '\'' +
                ", phone='" + phone + '\'' +
                '}';
    }
}

第四步骤、声明一个静态的获取构造对象的方法

package com.chinamsp.mytest.pattern.builder;


class Persion {

    private String name;
    private Integer age;
    private String address;
    private String phone;

    public static Builder builder() {
        Builder builder = new Builder();
        return builder;
    }

    public Persion(Builder builder) {
        this.name = builder.name;
        this.age = builder.age;
        this.address = builder.address;
        this.phone = builder.phone;
    }


    public static class Builder {
        private String name;
        private Integer age;
        private String address;
        private String phone;

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

        public Builder age(Integer age) {
            this.age = age;
            return this;
        }

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

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

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

    @Override
    public String toString() {
        return "Persion{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", address='" + address + '\'' +
                ", phone='" + phone + '\'' +
                '}';
    }
}

下面调用试试看

 public static void main(String[] args) {
        Persion per = Persion.builder()
                .address("xxx")
                .age(20)
                .name("账单")
                .phone("34213123")
                .build();
        System.out.println(per.toString());
    }

到此已经完成了，概念性的东西小伙伴们直接去维基百科搜索吧，这个小小的demo仅仅提供参考

下面是个人理解

建造者模式有点是可以根据实际业务场景去判断各个参数动态的创建一个统一的入参数对象，在一半类中属性繁多的情况下这么去创建一个对象赋值属性很清晰优雅