Coding 生涯已經有1年4個月了，雖然比較熟悉公司框架，用起來還比較熟練，但是回頭想想，其實自己還是停留在新手階段，與剛出學校的那些“大俠”們不相上下。特別是昨天看到我們的CTO－BridGu(相信去過javaeye的朋友沒有不知道這個名字的吧)給我改寫的一段程序以后，感覺自己的程序是那么的幼稚。絲毫沒有professional的感覺，很是慚愧！
這個功能是一個解析String生成function的功能，當然格式要求非常嚴格的，而且格式驗證也是一個不可缺少，而且是非常重要的環(huán)節(jié)。
不知道你看到這個功能腦子里面想到是什么樣的解決方案呢？我沒有多想，拿起來就當String來處理，split, substring etc.
看看程序吧：
下面是我的方法，暫且說是方法吧：
?1????public?void?addFunction(String?prototype,Long?comId)throws?AlpineException{
?2????????ModDao?dao?=?(ModDao)this.getDao("modDao");
?3????????Components?com?=?this.findByPrimaryKey(Components.class,?comId);
?4????????Functions?function?=?new?Functions();
?5????????function.setComponent(com);
?6????????prototype?=?delDupSpace(prototype);
?7????????String[]?funTtemp?=?prototype.split("\n");
?8????????String?fun?=?funTtemp[0];
?9????????if(fun.indexOf("(")?==?-1||fun.indexOf(")")?==?-1){
10????????????throw?new?AlpineException(ErrorCode.FUNCTION_FORMAT_ERROR);
11????????}
12????????String?funHead?=?fun.substring(0,fun.indexOf("("));
13????????String[]?typeAndHead?=?funHead.split("?");
14????????if(typeAndHead.length?<?1){
15????????????throw?new?AlpineException(ErrorCode.FUNCTION_FORMAT_ERROR);
16????????}else{
17????????????if(typeAndHead.length?>1){
18????????????????function.setReturnType(typeAndHead[0]);
19????????????????function.setFunctionName(typeAndHead[typeAndHead.length-1]);
20????????????}else{
21????????????????function.setReturnType("void");
22????????????????function.setFunctionName(typeAndHead[0]);
23????????????}
24????????????if(fun.indexOf("http://")?!=?-1){
25????????????????String?exp?=?fun.substring(fun.indexOf(";")+1);
26????????????????exp?=?exp.replaceAll(" ",?"");
27????????????????function.setExplanation(exp);
28????????????}
29????????????this.insert(function);
30????
31????????????String?paStr?=?fun.substring(fun.indexOf("(")+1,?fun.indexOf(")"));
32????????????if(!StringHelper.isEmpty(paStr)){
33????????????????String[]?pas?=?paStr.split(",");
34????????????????for?(int?i?=?0;?i?<?pas.length;?i++)?{
35????????????????????Parameters?parameter?=?new?Parameters();
36????????????????????String[]?pars?=?pas[i].split("?");
37????????????????????if(pars.length?<?2?||?pars.length?>?3){
38????????????????????????throw?new?AlpineException(ErrorCode.FUNCTION_FORMAT_ERROR);
39????????????????????}else{
40????????????????????????if(pars.length?==?2){
41????????????????????????????Parameters?paDup?=?dao.getParameterByPaName(pars[1],?function.getId());
42????????????????????????????if(paDup?!=?null)
43????????????????????????????????throw?new?AlpineException(ErrorCode.FUNCTION_FORMAT_ERROR);
44????????????????????????????????
45????????????????????????????parameter.setParameterName(pars[1]);
46????????????????????????????parameter.setParameterType(pars[0]);
47????????????????????????????parameter.setInOrOut("In");
48????????????????????????}
49????????????????????????if(pars.length?==?3){
50????????????????????????????Parameters?paDup?=?dao.getParameterByPaName(pars[2],?function.getId());
51????????????????????????????if(paDup?!=?null)
52????????????????????????????????throw?new?AlpineException(ErrorCode.FUNCTION_FORMAT_ERROR);
53????????????????????????????
54????????????????????????????parameter.setParameterName(pars[2]);
55????????????????????????????parameter.setParameterType(pars[1]);
56????????????????????????????if(pars[0].contains("In"))
57????????????????????????????????parameter.setInOrOut("In");
58????????????????????????????if(pars[0].contains("Out"))
59????????????????????????????????parameter.setInOrOut("Out");
60????????????????????????}
61????????????????????????parameter.setFunction(function);
62????????????????????????this.insert(parameter);
63????????????????????????parameter.setOrderF(parameter.getId());
64????????????????????????this.update(parameter);
65????????????????????}
66????????????????}
67????????????}
68????????????
69????????????for?(int?i?=?1;?i?<?funTtemp.length;?i++)?{//start?1
70????????????????String[]?paTemp?=?funTtemp[i].split(":");
71????????????????if(paTemp.length?==?2){
72????????????????????Parameters?parameter?=?dao.getParameterByPaName(paTemp[0].trim(),function.getId());
73????????????????????if(parameter?!=?null){
74????????????????????????parameter.setExplanation(paTemp[1]);
75????????????????????????this.update(parameter);
76????????????????????}
77????????????????}
78????????????}
79????????}
80????}
以下是BirdGu的方案：
??1public?class?FunctionParser?{
??2????public?static?class?Token?{
??3????????private?TokenType?type;
??4????????private?String?content;
??5????????public?Token(TokenType?type,?String?content)?{
??6????????????super();
??7????????????this.type?=?type;
??8????????????this.content?=?content;
??9????????}
?10????????public?String?getContent()?{
?11????????????return?content;
?12????????}
?13????????public?TokenType?getType()?{
?14????????????return?type;
?15????????}
?16????????
?17????????
?18????}
?19????
?20????private?enum?TokenType?{symbol,?leftParenthese,?rightParenthese,?inOutFlag,?comment,?comma};
?21????private?enum?TokenParseStatus?{start,?inSymbol,?comment1,?inOutFlag};
?22
?23????private?interface?ParseStatus?{
?24????????public?ParseStatus?process?(Functions?function,?Token?token,?Stack<String>?symbolStack)
?25????????throws?InvalidSyntaxException;
?26????}
?27????
?28????private?static?final?ParseStatus?START?=?new?ParseStatus()?{
?29????????public?ParseStatus?process(Functions?function,?Token?token,?Stack<String>?symbolStack)
?30????????throws?InvalidSyntaxException?{
?31????????????if?(token.getType()?==?TokenType.symbol)?{
?32????????????????symbolStack.push(token.getContent());
?33????????????????return?GOT_FIRST_SYMBOL;
?34????????????}?
?35????????????throw?new?InvalidSyntaxException?(token);
?36????????}
?37????};
?38????
?39????private?static?final?ParseStatus?GOT_FIRST_SYMBOL?=?new?ParseStatus?()?{
?40????????public?ParseStatus?process(Functions?function,?Token?token,?Stack<String>?symbolStack)?throws?InvalidSyntaxException?{
?41????????????if?(token.getType()?==?TokenType.leftParenthese)?{
?42????????????????function.setReturnType("void");
?43????????????????function.setFunctionName(symbolStack.pop());
?44????????????????return?WAITING_FIRST_ARG;
?45????????????}?else?if?(token.getType()?==?TokenType.symbol)?{
?46????????????????function.setFunctionName(token.getContent());
?47????????????????function.setReturnType(symbolStack.pop());
?48????????????????return?BEFORE_ARG_DEF;
?49????????????}?
?50????????????throw?new?InvalidSyntaxException?(token);
?51????????}
?52????};
?53????
?54????private?static?final?ParseStatus?BEFORE_ARG_DEF?=?new?ParseStatus?()?{
?55????????public?ParseStatus?process(Functions?function,?Token?token,?Stack<String>?symbolStack)?throws?InvalidSyntaxException?{
?56????????????if?(token.getType()?==?TokenType.leftParenthese)?{
?57????????????????return?WAITING_FIRST_ARG;
?58????????????}
?59????????????throw?new?InvalidSyntaxException?(token);
?60????????}
?61????};
?62????
?63????private?static?final?ParseStatus?WAITING_FIRST_ARG?=?new?ParseStatus?()?{
?64
?65????????public?ParseStatus?process(Functions?function,?Token?token,?Stack<String>?symbolStack)?throws?InvalidSyntaxException?{
?66????????????if?(token.getType()?==?TokenType.rightParenthese)?{
?67????????????????return?AFTER_ARG_DEF;
?68????????????}?else?if?(token.getType()?==?TokenType.symbol)?{
?69????????????????symbolStack.push(token.getContent());
?70????????????????return?GOT_ARG_TYPE;
?71????????????}?else?if?(token.getType()?==?TokenType.inOutFlag)?{
?72????????????????symbolStack.push?(token.getContent());
?73????????????????return?GOT_IN_OUT_FLAG;
?74????????????}
?75????????????throw?new?InvalidSyntaxException?(token);????
?76????????}
?77????};
?78????
?79????private?static?final?ParseStatus?GOT_IN_OUT_FLAG?=?new?ParseStatus?()?{
?80????????public?ParseStatus?process(Functions?function,?Token?token,?Stack<String>?symbolStack)?throws?InvalidSyntaxException?{
?81????????????if?(token.getType()?==?TokenType.symbol)?{
?82????????????????symbolStack.push(token.getContent());
?83????????????????return?GOT_ARG_TYPE;
?84????????????}
?85????????????throw?new?InvalidSyntaxException?(token);????
?86????????}
?87????};
?88????
?89????private?static?final?ParseStatus?GOT_ARG_TYPE?=?new?ParseStatus?()?{
?90????????public?ParseStatus?process(Functions?function,?Token?token,?Stack<String>?symbolStack)?throws?InvalidSyntaxException?{
?91????????????if?(token.getType()?==?TokenType.symbol)?{
?92????????????????Parameters?param?=?new?Parameters?();
?93????????????????param.setParameterName(token.getContent());
?94????????????????param.setParameterType(symbolStack.pop());
?95????????????????String?inOutFlag?=?"In";
?96????????????????if?(!symbolStack.isEmpty())?{
?97????????????????????inOutFlag?=?symbolStack.pop();
?98????????????????}
?99????????????????param.setInOrOut(inOutFlag);
100????????????????function.adParameter(param);
101????????????????return?GOT_ARG_VALUE;
102????????????}
103????????????throw?new?InvalidSyntaxException?(token);????
104????????}
105????};
106????
107????private?static?final?ParseStatus?GOT_ARG_VALUE?=?new?ParseStatus?()?{
108????????public?ParseStatus?process(Functions?function,?Token?token,?Stack<String>?symbolStack)?throws?InvalidSyntaxException?{
109????????????if?(token.getType()?==?TokenType.rightParenthese)?{
110????????????????return?AFTER_ARG_DEF;
111????????????}?else?if?(token.getType()?==?TokenType.comma)?{
112????????????????return?WAITING_ARG;
113????????????}
114????????????throw?new?InvalidSyntaxException?(token);????
115????????}
116????};
117????
118????private?static?final?ParseStatus?WAITING_ARG?=?new?ParseStatus?()?{
119????????public?ParseStatus?process(Functions?function,?Token?token,?Stack<String>?symbolStack)?throws?InvalidSyntaxException?{
120????????????if?(token.getType()?==?TokenType.symbol)?{
121????????????????symbolStack.push(token.getContent());
122????????????????return?GOT_ARG_TYPE;
123????????????}?else?if(token.getType()?==?TokenType.inOutFlag)?{
124????????????????symbolStack.push(token.getContent());
125????????????????return?GOT_IN_OUT_FLAG;
126????????????}
127????????????return?null;
128????????}
129????};
130????
131????private?static?final?ParseStatus?AFTER_ARG_DEF?=?new?ParseStatus?()?{
132????????public?ParseStatus?process(Functions?function,?Token?token,?Stack<String>?symbolStack)?throws?InvalidSyntaxException?{
133????????????if?(token.getType()?==?TokenType.comment)?{
134????????????????function.setExplanation(token.getContent());
135????????????????return?END;
136????????????}
137????????????throw?new?InvalidSyntaxException?(token);
138????????}
139????};
140????
141????private?static?final?ParseStatus?END?=?new?ParseStatus?()?{
142????????public?ParseStatus?process(Functions?function,?Token?token,?Stack<String>?symbolStack)?throws?InvalidSyntaxException?{
143????????????throw?new?InvalidSyntaxException?(token);
144????????}
145????};
146????
147????private?StringBuffer?currentLine;
148????private?int?index;
149????private?Functions?function;
150????
151????public?Functions?parse(String?content)?throws?InvalidSyntaxException?{
152????????if?(StringHelper.isEmpty(content))?{
153????????????throw?new?IllegalArgumentException?("content?is?empty.");
154????????}
155????????StringTokenizer?tokenizer?=?new?StringTokenizer?(content,?"\n");
156????????String?line?=?tokenizer.nextToken();
157????????parseFirstLine?(line);
158????????while?(tokenizer.hasMoreTokens())?{