Golang如何使用责任链模式串联处理步骤_Golang Chain of Responsibility模式实践

package main

import (
    "fmt"
    "strings"
)

// Request 表示请求数据
type Request struct {
    Email    string
    Username string
    Password string
}

// Handler 定义处理接口
type Handler interface {
    SetNext(handler Handler) Handler
    Handle(request *Request) string
}

// BaseHandler 提供默认的SetNext实现
type BaseHandler struct {
    next Handler
}

func (b *BaseHandler) SetNext(handler Handler) Handler {
    b.next = handler
    return handler
}

func (b *BaseHandler) Handle(request *Request) string {
    if b.next != nil {
        return b.next.Handle(request)
    }
    return ""
}

// EmailHandler 验证邮箱格式
type EmailHandler struct {
    BaseHandler
}

func (e *EmailHandler) Handle(request *Request) string {
    if !strings.Contains(request.Email, "@") {
        return "无效的邮箱格式"
    }
    return e.BaseHandler.Handle(request)
}

// UsernameHandler 检查用户名长度
type UsernameHandler struct {
    BaseHandler
}

func (u *UsernameHandler) Handle(request *Request) string {
    if len(request.Username) < 3 {
        return "用户名长度不能少于3个字符"
    }
    return u.BaseHandler.Handle(request)
}

// PasswordHandler 校验密码强度
type PasswordHandler struct {
    BaseHandler
}

func (p *PasswordHandler) Handle(request *Request) string {
    if len(request.Password) < 6 || !strings.ContainsAny(p.Password, "!@#$%^&*") {
        return "密码必须至少6位并包含特殊字符"
    }
    return p.BaseHandler.Handle(request)
}

func main() {
    // 创建各个处理器
    emailHandler := &EmailHandler{}
    usernameHandler := &UsernameHandler{}
    passwordHandler := &PasswordHandler{}

    // 组装链：email -> username -> password
    emailHandler.SetNext(usernameHandler).SetNext(passwordHandler)

    request := &Request{
        Email:    "user@example.com",
        Username: "jo",
        Password: "123456",
    }

    result := emailHandler.Handle(request)
    if result != "" {
        fmt.Printf("注册失败：%s\n", result)
    } else {
        fmt.Println("注册成功")
    }
}

注册失败：用户名长度不能少于3个字符