设计模式

最新推荐文章于 2025-04-09 22:55:57 发布

原创最新推荐文章于 2025-04-09 22:55:57 发布 · 189 阅读

0 ·

CC 4.0 BY-SA版权

本文详细探讨了两种常用的设计模式——单例模式和设计者模式，旨在帮助读者深化对软件设计原则的理解，提升代码的可维护性和复用性。

@[toc]设计模式

1、单例模式

package com.example.myapplication;

public class User {
    //2、成员位置初始化对象
    private  static User user = new User();
    private String name;
    //1、私有构造方法
    private User(){

    }
    //提供方法，给外界使用
    public static User getUser(){
        return  user;
    }

    //main 
    public static void main(String[] args) {
        User user = User.getUser();
        User user1 = User.getUser();
        if (user == user1){
            System.out.println("这是同一个对象");
        }
        System.out.println(user == user1);
    }

}

2、设计者模式

package com.example.myapplication;

public class Student {

    String name;
    int age;
    String email;
    String address;

    //重写toString
    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", email='" + email + '\'' +
                ", address='" + address + '\'' +
                '}';
    }

	//构造
    private Student(){

    }

    //内部类
    private static class Builder {
        private String name;
        private int age;
        private String email;
        private String address;

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

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

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

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

        //创建Student对象的
        public Student build() {
            Student student = new Student();
            student.name = this.name;
            student.age = this.age;
            student.email = this.email;
            student.address = this.address;
            return student;
        }


    }

    public static void main(String[] args) {
        Builder builder = new Builder();
        builder.setName("卤蛋").setAge(19).setEmail("1473372740@qq.com").setAddress("山东");
        Student build = builder.build();
        System.out.println(build.toString());
    }
}