缘起
Spring
目标
子目标（Day 4）
设计
OrderController.go
OrderController_Enhanced.go
IBeanRegistry.go
IRestController.go
IControllerRegistry.go

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 ```go 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) }

<a name="XFDpc"></a>
# IOrderService.go
订单持久化服务接口
```go
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）

老罗话编程

手撸golang 仿spring ioc/aop 之4 蓝图

缘起