手撸golang 仿spring ioc_aop 之4 蓝图

缘起

最近阅读 [Spring Boot技术内幕: 架构设计与实现原理] (朱智胜 , 2020.6)
本系列笔记拟采用golang练习之
Talk is cheap, show me the code.

Spring

Spring的主要特性：
1. 控制反转（Inversion of Control, IoC）
2. 面向容器
3. 面向切面（AspectOriented Programming, AOP）

源码gitee地址：
https://gitee.com/ioly/learning.gooop

原文链接：
https://my.oschina.net/ioly

目标

• 参考spring常用注解，使用golang编写“基于注解的静态代码增强器/生成器”

  • 配置： ComponentScan，Configuration, Bean

  • Bean声明：Component, Service, Controller

  • Bean注入：Autowried

  • AOP注解：Before, After, Around, PointCut

子目标（Day 4）

• 前两天都是在整外围接口，没说清楚到底要搞啥
• 今天以@RestController为例，把项目目标理清楚：
  • 以gin框架为基础，描述一个订单CRUD服务
  • 以@RestController为例，手写增强前后的代码，描绘如何增强
  • 增强前，应当尽可能简洁，降低框架侵入性
  • 增强后，与框架很好的结合，把脏活累活默默干好

设计

• OrderController: 订单服务控制器
• OrderController_Enhanced：增强后的订单服务控制器
  • 添加SetOrderService方法以便依赖注入
  • 添加xxx_Enhanced方法，以集成到gin框架
  • 添加RegisterRestController方法，以注册到Bean容器
  • 添加init()方法，以便Bean容器引用
• IOrderService：订单持久化服务接口
• MockOrderService：订单持久化服务的实现，码略
• dto/, entity/: 订单服务的实体类和数值类，码略
• IBeanRegistry：bean注册表接口
• IRestController：RESTFul控制器接口
• IControllerRegistry：RESTFul控制器注册表及其默认实现

OrderController.go

订单服务控制器

package controller

import (
    "learning/gooop/spring/demo/order/dto"
    "learning/gooop/spring/demo/order/entity"
    "learning/gooop/spring/demo/order/service"
)

// OrderController handles rest requests for CRUD orders
// @RestController
// @RequestMapping path=/order
type OrderController struct {
    orderService service.IOrderService
}

// Save create or update an order
// @PostMapping
func (me *OrderController) Save(head *entity.OrderHeadEntity, items []*entity.OrderItemEntity) error {
    return me.orderService.Save(head, items)
}

// View gets order and order items
// @GetMapping
func (me *OrderController) View(orderID int) (error, *dto.OrderDTO) {
    return me.orderService.Get(orderID)
}

// Query query order headers by custom conditions
// @GetMapping
func (me *OrderController) Query(customerID int, statusFlag int, dateFrom string, dateTo string, pageNO int, pageSize int) (error, []*dto.OrderHeadDTO) {
    return me.orderService.Query(customerID, statusFlag, dateFrom, dateTo, pageNO, pageSize)
}

OrderController_Enhanced.go

增强后的订单服务控制器

• 添加SetOrderService方法以便依赖注入
• 添加xxx_Enhanced方法，以集成到gin框架
• 添加RegisterRestController方法，以注册到Bean容器
• 添加init()方法，以便Bean容器引用

package controller

import (
    "github.com/gin-gonic/gin"
    "learning/gooop/spring/demo/framework/bean/controller"
    "learning/gooop/spring/demo/order/dto"
    "learning/gooop/spring/demo/order/entity"
    "learning/gooop/spring/demo/order/service"
    "net/http"
)

// OrderController_Enhanced handles rest requests for CRUD orders
// @RestController
// @RequestMapping path=/order
type OrderController_Enhanced struct {
    // @Autowired
    orderService service.IOrderService
}

// SetOrderService is auto generated setter method for injecting service.IOrderService into me.orderService
func (me *OrderController_Enhanced) SetOrderService(it interface{}) {
    me.orderService = it.(service.IOrderService)
}

// Save create or update an order
// @PostMapping
func (me *OrderController_Enhanced) Save(head *entity.OrderHeadEntity, items []*entity.OrderItemEntity) error {
    return me.orderService.Save(head, items)
}

// OrderController_Save_ParamsDTO is auto generated struct for wrapping parameters of OrderController.Save
type OrderController_Save_ParamsDTO struct {
    Order *entity.OrderHeadEntity
    Items []*entity.OrderItemEntity
}

// View_Enhanced is the enhanced version of Save
func (me *OrderController_Enhanced) Save_Enhanced(c *gin.Context) {
    r := new(OrderController_Save_ParamsDTO)
    e := c.BindJSON(r)
    if e != nil {
        c.JSON(http.StatusBadRequest, gin.H{"ok": false, "error": e.Error()})
        return
    }

    e = me.Save(r.Order, r.Items)
    if e != nil {
        c.JSON(http.StatusInternalServerError, gin.H{"ok": false, "error": e.Error()})
        return
    }

    c.JSON(http.StatusOK, gin.H{"ok": true})
}

// View gets order and order items
// @GetMapping
func (me *OrderController_Enhanced) View(orderID int) (error, *dto.OrderDTO) {
    return me.orderService.Get(orderID)
}

// View_Enhanced is the enhanced version of View
func (me *OrderController_Enhanced) View_Enhanced(c *gin.Context) {
    id := c.GetInt("id")
    e, d := me.View(id)
    if e != nil {
        c.JSON(http.StatusInternalServerError, gin.H{"ok": false, "error": e.Error()})
    }

    c.JSON(http.StatusOK, d)
}

// Query query order headers by custom conditions
// @GetMapping
func (me *OrderController_Enhanced) Query(customerID int, statusFlag int, dateFrom string, dateTo string, pageNO int, pageSize int) (error, []*dto.OrderHeadDTO) {
    panic("implements me")
}

// OrderController_Query_ParamsDTO is auto generated struct for wrapping parameters of PagedQuery
type OrderController_Query_ParamsDTO struct {
    CustomerID int
    StatusFlag int
    DateFrom   string
    DateTO     string
    PageNO     int
    PageSize   int
}

// Query_Enhanced is the enhanced version of PagedQuery
func (me *OrderController_Enhanced) Query_Enhanced(c *gin.Context) {
    r := new(OrderController_Query_ParamsDTO)
    e := c.Bind(r)
    if e != nil {
        c.JSON(http.StatusBadRequest, gin.H{"ok": false, "error": e.Error()})
        return
    }

    e, d := me.Query(r.CustomerID, r.StatusFlag, r.DateFrom, r.DateTO, r.PageNO, r.PageSize)
    if e != nil {
        c.JSON(http.StatusInternalServerError, gin.H{"ok": false, "error": e.Error()})
        return
    }

    c.JSON(http.StatusOK, gin.H{"ok": true, "data": d})
}

// RegisterRestController is auto generated to implements controller.IRestController interface
func (me *OrderController_Enhanced) RegisterRestController(r *gin.Engine) {
    r.POST("/order/save", me.Save_Enhanced)
    r.GET("/order/view", me.View_Enhanced)
    r.GET("/order/query", me.Query_Enhanced)
}

// init is auto generated to register OrderController_Enhanced into controller.ControllerRegistry
func init() {
    it := new(OrderController_Enhanced)
    controller.ControllerRegistry.Register(it)
}

IOrderService.go

订单持久化服务接口

package service

import (
    "learning/gooop/spring/demo/order/dto"
    "learning/gooop/spring/demo/order/entity"
)

type IOrderService interface {
    Save(head *entity.OrderHeadEntity, items []*entity.OrderItemEntity) error
    Get(orderID int) (error, *dto.OrderDTO)
    Query(customerID int, statusFlag int, dateFrom string, dateTo string, pageNO int, pageSize int) (error, []*dto.OrderHeadDTO)
}

IBeanRegistry.go

bean注册表接口

package bean

type IBeanRegistry interface {
    All() []interface{}
}

IRestController.go

RESTFul控制器接口

package controller

import "github.com/gin-gonic/gin"

type IRestController interface {
    RegisterRestController(r *gin.Engine)
}

IControllerRegistry.go

RESTFul控制器注册表及其默认实现

package controller

import (
    "github.com/gin-gonic/gin"
    "learning/gooop/spring/demo/framework/bean"
    "sync"
)

type IControllerRegistry interface {
    bean.IBeanRegistry

    Register(it IRestController)
    Apply(r *gin.Engine)
}

type tDefaultControllerRegistry struct {
    rwmutex *sync.RWMutex
    items   []IRestController
}

func (me *tDefaultControllerRegistry) All() []interface{} {
    me.rwmutex.RLock()
    defer me.rwmutex.RUnlock()

    all := make([]interface{}, len(me.items))
    for i, it := range me.items {
        all[i] = it
    }
    return all
}

func (me *tDefaultControllerRegistry) Register(it IRestController) {
    me.rwmutex.Lock()
    defer me.rwmutex.Unlock()

    me.items = append(me.items, it)
}

func (me *tDefaultControllerRegistry) Apply(r *gin.Engine) {
    me.rwmutex.RLock()
    defer me.rwmutex.RLock()

    for _, it := range me.items {
        it.RegisterRestController(r)
    }
}

func newDefaultControllerRegistry() IControllerRegistry {
    return &tDefaultControllerRegistry{
        new(sync.RWMutex),
        []IRestController{},
    }
}

var ControllerRegistry = newDefaultControllerRegistry()

（未完待续）