手撸golang 仿spring ioc/aop 之3
缘起
最近阅读 [Offer来了:Java面试核心知识点精讲(框架篇)] (王磊 , 2020.6)
本系列笔记拟采用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系统应用框架。
它有很多优秀的特性,很多公司都选择把
Spring作为产品或项目的基础开发架构。
Spring的主要特性包括:
1. 轻量
2. 控制反转(Inversion of Control, IoC)
3. 面向容器
4. 面向切面(AspectOriented Programming, AOP)
5. 框架灵活
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 3)
- 添加ProjectCmd以支持项目定义
- 添加文本扫描的辅助类:Chars.go, Tokens.go
- 定义代码生成服务接口ICodingService及其支撑接口
设计
- command/ProjectCmd: 项目定义指令
- common/Chars: 字符识别辅助类
- common/Tokens: 组合文本识别辅助类
- service/ICodingService: 代码生成服务接口
- service/iCodingContext: 代码生成上下文
- service/iCodingState:状态模式下的服务状态
- service/iCmdRunner:定义指令执行器接口,具体执行拟走责任链模式以便扩展
- service/tInitialState:默认的服务状态
command/ProjectCmd.go
项目定义指令
package project_cmd
import (
"errors"
"fmt"
"learning/gooop/spring/autogen/command"
"learning/gooop/spring/autogen/common"
"os"
"strings"
)
// ProjectCmd defines a project with name and dir
type ProjectCmd struct {
name string
dir string
}
// ProjectCmdBuilder parses cli input and creates a ProjectCmd instance
type ProjectCmdBuilder int
const gProjectCmdPrefix = "project "
var gErrorInvalidProjectCmd = errors.New("invalid project cmd")
func (me *ProjectCmd) String() string {
return fmt.Sprintf("project %s %s", me.name, me.dir)
}
func (me *ProjectCmd) Apply(ctx command.ICmdContext) error {
panic("implements me")
}
func (me *ProjectCmdBuilder) Build(line string) (error, command.ICmd) {
if !common.Tokens.MatchString(line, gProjectCmdPrefix) {
return nil, nil
}
line = strings.TrimSpace(line[len(gProjectCmdPrefix):])
b,name := common.Tokens.MatchIdentifier(line)
if !b {
return gErrorInvalidProjectCmd, nil
}
line = line[len(name):]
b, spaces := common.Tokens.MatchSpaces(line)
if !b {
return gErrorInvalidProjectCmd, nil
}
line = line[len(spaces):]
b, dir := common.Tokens.MatchDir(line)
if !b {
return gErrorInvalidProjectCmd, nil
}
_,e := os.Stat(dir)
if e != nil {
return e, nil
}
return nil, &ProjectCmd{ name, dir }
}
common/Chars.go
字符识别辅助类
package common
type tChars int
var Chars = new(tChars)
func (me *tChars) IsSpace(it rune) bool {
switch it {
case ' ':
return true
case '\t':
return true
case '\r':
return true
case '\n':
return true
}
return false
}
func (me *tChars) Is09(it rune) bool {
return it >= '0' && it <= '9'
}
func (me *tChars) Is19(it rune) bool {
return it >= '1' && it <= '9'
}
func (me *tChars) IsLetter(it rune) bool {
return (it >= 'a' && it <= 'z') || (it >= 'A' && it <= 'Z')
}
func (me *tChars) IsUnderscore(it rune) bool {
return it == '_'
}
func (me *tChars) IsLB(it rune) bool {
return it == '('
}
func (me *tChars) IsRB(it rune) bool {
return it == ')'
}
func (me *tChars) IsChar(it rune, args... rune) bool {
for _,v := range args {
if v == it {
return true
}
}
return false
}
func (me *tChars) IsSQuote(it rune) bool {
return me.IsChar(it, '\'')
}
func (me *tChars) IsDQuote(it rune) bool {
return me.IsChar(it, '"')
}
func (me *tChars) IsRSplash(it rune) bool {
return me.IsChar(it, '\\')
}
func (me *tChars) IsLSplash(it rune) bool {
return me.IsChar(it, '/')
}
common/Tokens.go
组合文本识别辅助类
package common
import (
"regexp"
"strings"
"sync"
)
type tTokens struct {
cache map[string]*regexp.Regexp
rwmutex *sync.RWMutex
}
var Tokens = newTokensLib()
func newTokensLib() *tTokens {
it := new(tTokens)
it.init()
return it
}
func (me *tTokens) init() {
me.cache = make(map[string]*regexp.Regexp)
me.rwmutex = new(sync.RWMutex)
}
func (me *tTokens) MatchString(s string, p string) bool {
return strings.HasPrefix(s, p)
}
func (me *tTokens) MatchRegexp(s string, p string) (bool, string) {
me.rwmutex.RLock()
r,ok := me.cache[p]
me.rwmutex.RUnlock()
if !ok {
me.rwmutex.Lock()
if r,ok = me.cache[p];!ok {
r,_ = regexp.Compile(p)
}
me.rwmutex.Unlock()
}
if r == nil {
return false, ""
}
if !r.MatchString(s) {
return false, ""
}
return true, r.FindString(s)
}
func (me *tTokens) MatchIdentifier(s string) (bool, string) {
return me.MatchRegexp(s, "^[_a-zA-Z]\\w{0,99}}")
}
func (me *tTokens) MatchSpaces(s string) (bool, string) {
return me.MatchRegexp(s, "^\\s+")
}
func (me *tTokens) MatchDir(s string) (bool, string) {
b,s := me.MatchRegexp(s, "^([a-zA-Z]\\:)?([\\\\/][^\\s/:*?<>|\\\"\\\\]+)+[\\/]?")
if b {
return b,s
}
b,s = me.MatchRegexp(s, "^\\\"([a-zA-Z]\\:)?([\\\\/][^/:*?<>|\\\"\\\\]+)+[\\/]?\\\"")
if b {
return b,s
}
b,s = me.MatchRegexp(s, "^'([a-zA-Z]\\:)?([\\\\/][^'/:*?<>|\\\"\\\\]+)+[\\/]?'")
if b {
return b,s
}
return false, ""
}
service/ICodingService.go
代码生成服务接口
package service
type ICodingService interface {
iCmdRunner
State() iCodingState
Start()
}
service/iCodingContext.go
代码生成上下文
package service
// iCodingContext provides context info for iCodingState instance
type iCodingContext interface {
HandleStateChanged(state iCodingState)
}
service/iCodingState.go
状态模式下的服务状态
package service
type iCodingState interface {
iCmdRunner
}
service/iCmdRunner.go
定义指令执行器接口,具体执行拟走责任链模式以便扩展
package service
import "learning/gooop/spring/autogen/command"
// iCmdRunner runs a user cmd
type iCmdRunner interface {
Run(cmd command.ICmd) error
}
service/tInitialState.go
默认的服务状态
package service
import (
"errors"
"learning/gooop/spring/autogen/command"
)
// tInitialState is the default state for a coding service
// it will only accept ProjectCmd
type tInitialState struct {
context iCodingContext
}
func newInitialState(c iCodingContext) iCodingState {
it := new(tInitialState)
it.init(c)
return it
}
func (me *tInitialState) init(c iCodingContext) {
me.context = c
}
var gErrorProjectDefineRequired = errors.New("project not defined: project <name> <dir>")
func (me *tInitialState) Run(cmd command.ICmd) error {
panic("implement me")
}
(未完待续)
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