本篇内容主要讲解“怎么用golang编写基于注解的静态代码增强器/生成器”，感兴趣的朋友不妨来看看。本文介绍的方法操作简单快捷，实用性强。下面就让小编来带大家学习“怎么用golang编写基于注解的静态代码增强器/生成器”吧!
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
参考spring boot常用注解，使用golang编写“基于注解的静态代码增强器/生成器”
今天继续the hard part：struct/field/method元素的扫描
common/Tokens.go：添加数据类型的词法解析支持
scanner/IStructScanner.go: 结构体扫描器的接口及实现
添加数据类型的词法解析支持：
分别解析基本类型/自定义类型/指针类型/数组类型/map类型
自定义类型需要注意排除'map'关键字
指针，数组和map类型都是复合类型，需递归解析
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, ""
}
func (me *tTokens) MatchDataType(s string) (bool, string) {
if ok,t := me.MatchBasicType(s);ok {
return true, t
}
if ok,t := me.MatchCustomType(s);ok {
return true, t
}
if ok,t := me.MatchPointerType(s);ok {
return true, t
}
if ok,t := me.MatchArrayType(s);ok {
return true, t
}
if ok,t := me.MatchMapType(s);ok {
return true, t
}
return false, ""
}
func (me *tTokens) MatchBasicType(s string) (bool, string) {
list := []string {
"int",
"string",
"bool",
"byte",
"int32",
"int64",
"uint32",
"uint64",
"float32",
"float64",
"int8",
"uint8",
"int16",
"uint16",
"time.Time",
}
for _,it := range list {
if me.MatchString(s, it) {
return true, it
}
}
return false, ""
}
func (me *tTokens) MatchCustomType(s string) (bool, string) {
t := s
b1, s1 := me.MatchRegexp(t, `^\w+\.`)
if b1 {
t = t[len(s1):]
}
b2, s2 := me.MatchRegexp(t, `^\w+`)
if !b2 {
return false, ""
}
if s2 == "map" {
// map is reserved word
return false, ""
}
return true, s1 + s2
}
func (me *tTokens) MatchPointerType(s string) (bool, string) {
t := s
if t[0] != '*' {
return false,""
}
t = t[1:]
b, s := me.MatchDataType(t)
if !b {
return false, ""
}
return true, "*" + s
}
func (me *tTokens) MatchArrayType(s string) (bool, string) {
t := s
b1, s1 := me.MatchRegexp(s, `^\[\s*\d*\s*\]\s*`)
if !b1 {
return false, ""
}
t = t[len(s1):]
b2, s2 := me.MatchDataType(t)
if !b2 {
return false, ""
}
return true, s1 + s2
}
func (me *tTokens) MatchMapType(s string) (bool, string) {
t := s
s1 := "map"
if !me.MatchString(t, s1) {
return false, ""
}
t = t[len(s1):]
b2, s2 := me.MatchRegexp(t, `^\s*\[\s*`)
if !b2 {
return false, ""
}
t = t[len(s2):]
b3,s3 := me.MatchDataType(t)
if !b3 {
return false, ""
}
t = t[len(s3):]
b4, s4 := me.MatchRegexp(t, `^\s*\]\s*`)
if !b4 {
return false, ""
}
t = t[len(s4):]
b5, s5 := me.MatchDataType(t)
if !b5 {
return false, ""
}
return true, s1 + s2 + s3 + s4 + s5
}结构体扫描器的接口及实现
package scanner
import (
"errors"
"learning/gooop/spring/autogen/common"
"learning/gooop/spring/autogen/domain"
"regexp"
"strings"
)
type IStructScanner interface {
ScanStruct(file *domain.CodeFileInfo)
}
type tStructScanner int
func (me *tStructScanner) ScanStruct(file *domain.CodeFileInfo) {
bInStruct := false
var stru *domain.StructInfo
for lineNO,line := range file.CleanLines {
if bInStruct {
// end?
if gStructEndRegexp.MatchString(line) {
bInStruct = false
me.scanMethod(stru, lineNO + 1)
stru = nil
continue
}
}
// start?
if gStructStartRegexp.MatchString(line) {
bInStruct = true
ss := gStructStartRegexp.FindAllString(line, -1)
stru := domain.NewStructInfo()
stru.LineNO = lineNO
stru.CodeFile = file
stru.Name = ss[1]
continue
}
// in struct block
ok,fname,ftype := me.scanField(line)
if ok {
stru.AppendField(lineNO, fname, ftype)
}
}
}
func (me *tStructScanner) scanField(line string) (ok bool, fldName string, fldType string) {
if !gFieldStartRegexp.MatchString(line) {
return false, "",""
}
fldName = strings.TrimSpace(gFieldStartRegexp.FindString(line))
fldType = strings.TrimSpace(line[len(fldName):])
return true, fldName, fldType
}
func (me *tStructScanner) scanMethod(stru *domain.StructInfo, fromLineNO int) {
for i,max := fromLineNO, len(stru.CodeFile.CleanLines);i <= max;i++ {
line := stru.CodeFile.CleanLines[i]
if !gMethodStartRegex.MatchString(line) {
continue
}
ss := gMethodStartRegex.FindAllString(line, -1)
// declare
declare := ss[0]
offset := len(declare)
// receiver
receiver := ss[1]
if receiver != stru.Name {
continue
}
method := domain.NewMethodInfo()
// name
method.Name = ss[2]
// method input args
e,args := me.scanMethodArgs(method, strings.TrimSpace(line[offset:]))
if e != nil {
panic(e)
}
offset += len(args)
// method return args
e = me.scanReturnArgs(method, strings.TrimSpace(line[offset:]))
if e != nil {
panic(e)
}
// end scan method
stru.AppendMethod(method)
}
}
func (me *tStructScanner) scanMethodArgs(method *domain.MethodInfo, s string) (error, string) {
t := s
offset := 0
for {
// name
b1, s1 := common.Tokens.MatchRegexp(t, `\w+(\s*,\s*\w+)\s+`)
if !b1 {
break
}
argNames := s1
offset += len(s1)
t = s[offset:]
// data type
b2, s2 := common.Tokens.MatchDataType(t)
if !b2 {
return gInvalidMethodArgs, ""
}
argDataType := s2
offset += len(s2)
t = s[offset:]
for _,it := range strings.Split(argNames, ",") {
method.AppendArgument(it, argDataType)
}
// ,\s+
b3, s3 := common.Tokens.MatchRegexp(t, `\s*,\s*`)
if !b3 {
break
}
offset += len(s3)
t = s[offset:]
}
return nil, s[0:offset]
}
func (me *tStructScanner) scanReturnArgs(method *domain.MethodInfo, s string) error {
// todo: fixme
panic("implements me")
}
var gStructStartRegexp = regexp.MustCompile(`^\s*type\s+(\w+)\s+struct\s+\{`)
var gStructEndRegexp = regexp.MustCompile(`^\s*}`)
var gFieldStartRegexp = regexp.MustCompile(`^\s*\w+\s+`)
var gMethodStartRegex = regexp.MustCompile(`\s*func\s+\(\s*\w+\s+\*?(\w+)\s*\)\s+(\w+)\s*\(`)
var gInvalidMethodArgs = errors.New("invalid method arguments")
var DefaultStructScanner IStructScanner = new(tStructScanner)到此，相信大家对“怎么用golang编写基于注解的静态代码增强器/生成器”有了更深的了解，不妨来实际操作一番吧！这里是亿速云网站，更多相关内容可以进入相关频道进行查询，关注我们，继续学习！
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