手撸golang spring ioc/aop 之2
缘起
最近浏览 [Offer来了：Java面试外围知识点精讲（框架篇）] (王磊 , 2020.6)
本系列笔记拟采纳golang练习之
Talk is cheap, show me the code.
Spring
Spring基于J2EE技术实现了一套轻量级的Java Web Service零碎利用框架。它有很多优良的个性，很多公司都抉择把Spring作为产品或我的项目的根底开发架构。Spring的个性包含轻量、管制反转（Inversion of Control, IoC）、面向容器、面向切面（AspectOriented Programming, AOP）和框架灵便等。源码gitee地址：https://gitee.com/ioly/learning.gooop原文链接：https://my.oschina.net/ioly指标
参考spring罕用注解，应用golang编写“基于注解的动态代码增强器/生成器”
- 配置： ComponentScan，Configuration, Bean
- Bean申明：Component, Service, Controller
- Bean注入：Autowried
- AOP注解：Before, After, Around, PointCut
子目标（Day 2）
构思app的运行模式：
- 本地standlone模式运行
- 提供基于cli的命令行实时交互
- 生成旁路代码：只扫描源代码，不批改源代码，加强后的代码加对立后缀
设计cli交互指令集：
- config save：保留配置
- config saveas <name>：另存配置
- watch add <dir>：增加代码扫描目录
- watch del <dir>：移除代码扫描目录
- watch list：显示以后扫描的代码目录汇合
- gen：生成加强代码，也就是扫描所有注解，并生成加强类和加强办法
设计
- config/IConfiguration：配置接口
- command/ICmd：指令接口
- command/ICmdBuilder：指令构建器接口
- command/ICmdContext：指令执行上下文接口
- config_cmd/SaveCmd: 保留配置
- config_cmd/SaveASCmd: 另存配置
- watch_cmd/AddCmd: 增加监督
- watch_cmd/DelCmd: 移除监督
- watch_cmd/ListCmd: 显示已监督目录的列表
- gen_cmd/GenCmd: 生成加强类和加强办法
- model/IEventDrivenModel：“事件驱动”的逻辑编排模型
- logger: 日志接口，略
config/IConfiguration.go
配置接口
package config// IConfiguration defines system configuration interfacetype IConfiguration interface { GetProjectName() string SetProjectName(string) GetWatchPaths() []string AddWatchPath(string) DelWatchPath(string) Save() error SaveAS(string) error}command/ICmd.go
指令接口
package commandimport "fmt"// ICmd defines cli command interfacetype ICmd interface { fmt.Stringer // Apply apply current command into use Apply(ICmdContext) error}command/ICmdBuilder.go
指令构建器接口
package command// ICmdBuilder parse input string and create an ICmd instancetype ICmdBuilder interface { Build(string) (error, ICmd)}command/ICmdContext.go
指令执行上下文接口
package commandimport "learning/gooop/spring/autogen/config"// ICmdContext provides context info for all commandstype ICmdContext interface { GetConfiguration() config.IConfiguration}config_cmd/SaveCmd.go
保留配置
package config_cmdimport ( "learning/gooop/spring/autogen/command")// SaveCmd calls service.Save() to save current configuration, in JSON formattype SaveCmd int// SaveCmdBuilder parse cli input and build a SaveCmd instancetype SaveCmdBuilder intconst gSaveCmdString = "config save"var gSaveCmdInstance = new(SaveCmd)func (me *SaveCmd) String() string { return gSaveCmdString}func (me *SaveCmd) Apply(c command.ICmdContext) error { // todo: fixme panic("implements me")}func (me *SaveCmdBuilder) Build(line string) (error, command.ICmd) { if line != gSaveCmdString { return nil, nil } return nil, gSaveCmdInstance}config_cmd/SaveASCmd.go
另存配置
package config_cmdimport ( "errors" "learning/gooop/spring/autogen/command" "strings")// SaveASCmd calls service.SaveAS() to save current config into specific file, in JSON formattype SaveASCmd struct { file string}// SaveASCmdBuilder parse cli input and returns a SaveASCmd instancetype SaveASCmdBuilder intconst gSaveASCmdPrefix = "config saveas "func (me *SaveASCmd) String() string { return gSaveASCmdPrefix + me.file}func (me *SaveASCmd) Apply(c command.ICmdContext) error { // todo: fixme panic("implements me")}func (me *SaveASCmdBuilder) Build(line string) (error, command.ICmd) { if !strings.HasPrefix(line, gSaveASCmdPrefix) { return nil, nil } file := strings.TrimSpace(line[len(gSaveASCmdPrefix):]) if len(file) <= 0 { return errors.New("empty file path"), nil } return nil, &SaveASCmd{file }}watch_cmd/AddCmd.go
增加监督
package watch_cmdimport ( "learning/gooop/spring/autogen/command" "os" "strings")// AddCmd calls service.WatchAdd() to add dir to watch listtype AddCmd struct { dir string}type AddCmdBuilder intvar gAddCmdPrefix = "watch add "func (me *AddCmd) String() string { return gAddCmdPrefix + me.dir}func (me *AddCmd) Apply(c command.ICmdContext) error { // todo: fixme panic("implements me")}func (me *AddCmdBuilder) Build(line string) (error, command.ICmd) { // check prefix if !strings.HasPrefix(line, gAddCmdPrefix) { return nil, nil } // get dir dir := strings.TrimSpace(line[len(gAddCmdPrefix):]) // check dir _,e := os.Stat(dir) if e != nil { return e, nil } // ok return nil, &AddCmd{dir }}watch_cmd/DelCmd.go
移除监督
package watch_cmdimport ( "learning/gooop/spring/autogen/command" "os" "strings")// DelCmd calls service.WatchDel() to remove dir from watch listtype DelCmd struct { dir string}type DelCmdBuilder intvar gDelCmdPrefix = "watch del "func (me *DelCmd) String() string { return gDelCmdPrefix + me.dir}func (me *DelCmd) Apply(c command.ICmdContext) error { // todo: fixme panic("implements me")}func (me *DelCmdBuilder) Build(line string) (error, command.ICmd) { // check prefix if !strings.HasPrefix(line, gDelCmdPrefix) { return nil, nil } // get dir dir := strings.TrimSpace(line[len(gAddCmdPrefix):]) // check dir _,e := os.Stat(dir) if e != nil { return e, nil } // ok return nil, &DelCmd{ dir }}watch_cmd/ListCmd.go
显示已监督目录的列表
package watch_cmdimport ( "learning/gooop/spring/autogen/command")// ListCmd calls service.WatchListtype ListCmd int// ListCmdBuilder parse cli input and try to build a ListCmd instancetype ListCmdBuilder intconst gListCmdString1 = "watch list"const gListCmdString2 = "watch ls"var gListCmdSingleton = new(ListCmd)func (me *ListCmd) String() string { return gListCmdString1}func (me *ListCmd) Apply(c command.ICmdContext) error { // todo: panic("implements me")}func (me *ListCmdBuilder) Build(line string) (error, command.ICmd) { if line != gListCmdString1 && line != gListCmdString2 { return nil, nil } return nil, gListCmdSingleton}gen_cmd/GenCmd.go
生成加强类和加强办法
package gen_cmdimport ( "learning/gooop/spring/autogen/command")// GenCmd calls service.Gen() to generate enhanced code files at oncetype GenCmd int// GenCmdBuilder parse cli input and try to build a GenCmd instancetype GenCmdBuilder intconst gGenCmdString = "gen"var gGenCmdSingleton = new(GenCmd)func (me *GenCmd) String() string { return gGenCmdString}func (me *GenCmd) Apply(c command.ICmdContext) error { panic("implements me")}func (me *GenCmdBuilder) Build(line string) (error, command.ICmd) { if line != gGenCmdString { return nil, nil } return nil, gGenCmdSingleton}model/IEventDrivenModel.go
“事件驱动”的逻辑编排模型
package model// IEventDrivenModel defines an event driven model for code arrangementtype IEventDrivenModel interface { Hook(e string, handleFunc TEventHandleFunc) Fire(e string, args ...interface{}) FireAsync(e string, args ...interface{})}type TEventHandleFunc func(e string, args ...interface{})type TEventDrivenModel struct { items map[string][]TEventHandleFunc}func (me *TEventDrivenModel) Hook(e string, handler TEventHandleFunc) { if me.items == nil { me.items = make(map[string][]TEventHandleFunc) } arr, ok := me.items[e] if ok { me.items[e] = append(arr, handler) } else { me.items[e] = []TEventHandleFunc{handler} }}func (me *TEventDrivenModel) Fire(e string, args ...interface{}) { if handlers, ok := me.items[e]; ok { for _, it := range handlers { it(e, args...) } }}func (me *TEventDrivenModel) FireAsync(e string, args ...interface{}) { go me.Fire(e, args...)}（未完待续）