初學node.js有感二

時間 2019-11-17

標籤初學 node.js node 欄目 Node.js 简体版

原文原文鏈接

node.js進階javascript

1、回顧與繼續css

對於一種語言的認識都是經歷這樣的一個過程的，首先從原生的環境（CMD）中開始學習，找到一門語言之間各類引用的本質和相互之間的調用方式，明澈各類依賴關係，在這個基礎上咱們能夠進行一些比較簡單的編程，可是卻老是感受到本身須要作不少底層的工做，開發的效率也比較低，所以在基本熟練的基礎上，咱們就須要使用IDE這種集成開發環境來進行大規模項目的開發和對接了。而node.js一樣如此，在這裏我推薦使用WebStorm來做爲node.js的IDE，在這種環境中咱們能夠便於跟蹤和調試和執行，而且有着優質的性能和文件列表，下載與安裝也比較簡單，須要注意的是網上有不少破解方法，咱們最好破解了再使用。上一章節中咱們對node.js的起源，設計思想，以及簡單的程序運行進行了詳細的闡述和整理，在這一章節，咱們繼續對node.js進行研究，將視線移向更遠的地方，大規模項目的開發和管理，仔細聯想一下咱們開發Java程序，C++，C#程序的時候，咱們老是離不開這些東西，包、命名空間、類、對象、調用、線程、同步異步、相對路徑、絕對路徑、環境變量、做用域等，一樣的，在node.js中，咱們也有相似的概念，而且node.js由於有npm這樣的包管理工具，使得其具備很大的靈活性和方便性，咱們能夠方便的使用別人的代碼而不須要知道內部的細節，相似於服務的調用，這樣能夠大大的節約咱們的時間，而且減小開發的成本，這種設計思想使得node.js有很強的生命力！html

2、WebStorm中的一些注意事項java

首先，咱們破解了軟件以後新建一個js文件，在裏面能夠輸入簡單的js執行語句，而後用shift+ctrl+F10或者shift+F10便可執行，同時能夠在控制檯輸出相應的結果，在這裏咱們要注意程序執行的機理，首先咱們打開設置能夠看到執行命令的其實就是咱們一直以來使用的解釋器node.exe，而且還有一個工做目錄，這個目錄很是重要，若是咱們選擇了和運行文件不同的位置可能致使文件沒法執行。一樣的，讓咱們運行一個最簡單的node.js程序，來看一下輸出的結果！node

 1 var http = require("http");  2 //建立服務器
 3 var server = http.createServer(function(req,res){  4     //每次接受請求以後作的事情
 5     //設置響應頭
 6     res.writeHead(200,{"Content-Type":"text/html;charset=UTF8"});  7     res.write("<ul>");  8     res.write("<li>hello,world</li>");  9     res.write("<li>hello,zyr</li>"); 10     res.write("</ul>"); 11     res.end("成功！"); 12 }); 13 server.listen(3100,"127.0.0.1");

讀取各類文件並顯示，經過異步操做和解析json完成：android

 1 var http = require("http");  2 var fs = require("fs");  3 var url = require("url");  4 var path = require("path");  5 
 6 var server = http.createServer(function(req,res){  7     var pathname = url.parse(req.url).pathname;  8     //判斷此時用戶輸入的地址是文件夾地址仍是文件地址
 9     //若是是文件夾地址，那麼自動請求這個文件夾中的index.html
10     if(pathname.indexOf(".") == -1){ 11         pathname += "/index.html"; 12  } 13     //輸入的網址是127.0.0.1/images/logo.png
14     //實際請求的是./static/images/logo.png
15     var fileURL = "./" + path.normalize("./static/" + pathname); 16     //獲得拓展名
17     var extname = path.extname(pathname); 18 
19     //把文件讀出來
20     fs.readFile(fileURL,function(err,data){ 21         //讀完以後作的事情
22         if(err){ 23             //文件不存在
24             res.writeHead(404,{"Content-Type":"text/html;charset=UTF8"}) 25             res.end("404,頁面沒有找到"); 26  } 27         //讀完以後作的事情
28         getMime(extname,function(mime){ 29             res.writeHead(200,{"Content-Type":mime}) 30  res.end(data); 31  }); 32  }); 33 }); 34 
35 server.listen(3100,"127.0.0.1"); 36 
37 function getMime(extname,callback){ 38     //讀取mime.json文件，獲得JSON，根據extname key ，返回對應的value
39     //讀取文件
40     fs.readFile("./mime.json",function(err,data){ 41         if(err){ 42             throw Error("找不到mime.json文件！"); 43             return; 44  } 45         //轉成JSON
46         var mimeJSON = JSON.parse(data); 47         var mime =  mimeJSON[extname]  || "text/plain"; 48         //執行回調函數，mime類型字符串，就是它的參數
49  callback(mime); 50  }); 51 }

所使用的json文件：git

{ ".323":"text/h323" , ".3gp":"video/3gpp" , ".aab":"application/x-authoware-bin" , ".aam":"application/x-authoware-map" , ".aas":"application/x-authoware-seg" , ".acx":"application/internet-property-stream" , ".ai":"application/postscript" , ".aif":"audio/x-aiff" , ".aifc":"audio/x-aiff" , ".aiff":"audio/x-aiff" , ".als":"audio/X-Alpha5" , ".amc":"application/x-mpeg" , ".ani":"application/octet-stream" , ".apk":"application/vnd.android.package-archive" , ".asc":"text/plain" , ".asd":"application/astound" , ".asf":"video/x-ms-asf" , ".asn":"application/astound" , ".asp":"application/x-asap" , ".asr":"video/x-ms-asf" , ".asx":"video/x-ms-asf" , ".au":"audio/basic" , ".avb":"application/octet-stream" , ".avi":"video/x-msvideo" , ".awb":"audio/amr-wb" , ".axs":"application/olescript" , ".bas":"text/plain" , ".bcpio":"application/x-bcpio" , ".bin ":"application/octet-stream" , ".bld":"application/bld" , ".bld2":"application/bld2" , ".bmp":"image/bmp" , ".bpk":"application/octet-stream" , ".bz2":"application/x-bzip2" , ".c":"text/plain" , ".cal":"image/x-cals" , ".cat":"application/vnd.ms-pkiseccat" , ".ccn":"application/x-cnc" , ".cco":"application/x-cocoa" , ".cdf":"application/x-cdf" , ".cer":"application/x-x509-ca-cert" , ".cgi":"magnus-internal/cgi" , ".chat":"application/x-chat" , ".class":"application/octet-stream" , ".clp":"application/x-msclip" , ".cmx":"image/x-cmx" , ".co":"application/x-cult3d-object" , ".cod":"image/cis-cod" , ".conf":"text/plain" , ".cpio":"application/x-cpio" , ".cpp":"text/plain" , ".cpt":"application/mac-compactpro" , ".crd":"application/x-mscardfile" , ".crl":"application/pkix-crl" , ".crt":"application/x-x509-ca-cert" , ".csh":"application/x-csh" , ".csm":"chemical/x-csml" , ".csml":"chemical/x-csml" , ".css":"text/css" , ".cur":"application/octet-stream" , ".dcm":"x-lml/x-evm" , ".dcr":"application/x-director" , ".dcx":"image/x-dcx" , ".der":"application/x-x509-ca-cert" , ".dhtml":"text/html" , ".dir":"application/x-director" , ".dll":"application/x-msdownload" , ".dmg":"application/octet-stream" , ".dms":"application/octet-stream" , ".doc":"application/msword" , ".docx":"application/vnd.openxmlformats-officedocument.wordprocessingml.document" , ".dot":"application/msword" , ".dvi":"application/x-dvi" , ".dwf":"drawing/x-dwf" , ".dwg":"application/x-autocad" , ".dxf":"application/x-autocad" , ".dxr":"application/x-director" , ".ebk":"application/x-expandedbook" , ".emb":"chemical/x-embl-dl-nucleotide" , ".embl":"chemical/x-embl-dl-nucleotide" , ".eps":"application/postscript" , ".epub":"application/epub+zip" , ".eri":"image/x-eri" , ".es":"audio/echospeech" , ".esl":"audio/echospeech" , ".etc":"application/x-earthtime" , ".etx":"text/x-setext" , ".evm":"x-lml/x-evm" , ".evy":"application/envoy" , ".exe":"application/octet-stream" , ".fh4":"image/x-freehand" , ".fh5":"image/x-freehand" , ".fhc":"image/x-freehand" , ".fif":"application/fractals" , ".flr":"x-world/x-vrml" , ".flv":"flv-application/octet-stream" , ".fm":"application/x-maker" , ".fpx":"image/x-fpx" , ".fvi":"video/isivideo" , ".gau":"chemical/x-gaussian-input" , ".gca":"application/x-gca-compressed" , ".gdb":"x-lml/x-gdb" , ".gif":"image/gif" , ".gps":"application/x-gps" , ".gtar":"application/x-gtar" , ".gz":"application/x-gzip" , ".h":"text/plain" , ".hdf":"application/x-hdf" , ".hdm":"text/x-hdml" , ".hdml":"text/x-hdml" , ".hlp":"application/winhlp" , ".hqx":"application/mac-binhex40" , ".hta":"application/hta" , ".htc":"text/x-component" , ".htm":"text/html" , ".html":"text/html" , ".hts":"text/html" , ".htt":"text/webviewhtml" , ".ice":"x-conference/x-cooltalk" , ".ico":"image/x-icon" , ".ief":"image/ief" , ".ifm":"image/gif" , ".ifs":"image/ifs" , ".iii":"application/x-iphone" , ".imy":"audio/melody" , ".ins":"application/x-internet-signup" , ".ips":"application/x-ipscript" , ".ipx":"application/x-ipix" , ".isp":"application/x-internet-signup" , ".it":"audio/x-mod" , ".itz":"audio/x-mod" , ".ivr":"i-world/i-vrml" , ".j2k":"image/j2k" , ".jad":"text/vnd.sun.j2me.app-descriptor" , ".jam":"application/x-jam" , ".jar":"application/java-archive" , ".java":"text/plain" , ".jfif":"image/pipeg" , ".jnlp":"application/x-java-jnlp-file" , ".jpe":"image/jpeg" , ".jpeg":"image/jpeg" , ".jpg":"image/jpeg" , ".jpz":"image/jpeg" , ".js":"application/x-javascript" , ".jwc":"application/jwc" , ".kjx":"application/x-kjx" , ".lak":"x-lml/x-lak" , ".latex":"application/x-latex" , ".lcc":"application/fastman" , ".lcl":"application/x-digitalloca" , ".lcr":"application/x-digitalloca" , ".lgh":"application/lgh" , ".lha":"application/octet-stream" , ".lml":"x-lml/x-lml" , ".lmlpack":"x-lml/x-lmlpack" , ".log":"text/plain" , ".lsf":"video/x-la-asf" , ".lsx":"video/x-la-asf" , ".lzh":"application/octet-stream" , ".m13":"application/x-msmediaview" , ".m14":"application/x-msmediaview" , ".m15":"audio/x-mod" , ".m3u":"audio/x-mpegurl" , ".m3url":"audio/x-mpegurl" , ".m4a":"audio/mp4a-latm" , ".m4b":"audio/mp4a-latm" , ".m4p":"audio/mp4a-latm" , ".m4u":"video/vnd.mpegurl" , ".m4v":"video/x-m4v" , ".ma1":"audio/ma1" , ".ma2":"audio/ma2" , ".ma3":"audio/ma3" , ".ma5":"audio/ma5" , ".man":"application/x-troff-man" , ".map":"magnus-internal/imagemap" , ".mbd":"application/mbedlet" , ".mct":"application/x-mascot" , ".mdb":"application/x-msaccess" , ".mdz":"audio/x-mod" , ".me":"application/x-troff-me" , ".mel":"text/x-vmel" , ".mht":"message/rfc822" , ".mhtml":"message/rfc822" , ".mi":"application/x-mif" , ".mid":"audio/mid" , ".midi":"audio/midi" , ".mif":"application/x-mif" , ".mil":"image/x-cals" , ".mio":"audio/x-mio" , ".mmf":"application/x-skt-lbs" , ".mng":"video/x-mng" , ".mny":"application/x-msmoney" , ".moc":"application/x-mocha" , ".mocha":"application/x-mocha" , ".mod":"audio/x-mod" , ".mof":"application/x-yumekara" , ".mol":"chemical/x-mdl-molfile" , ".mop":"chemical/x-mopac-input" , ".mov":"video/quicktime" , ".movie":"video/x-sgi-movie" , ".mp2":"video/mpeg" , ".mp3":"audio/mpeg" , ".mp4":"video/mp4" , ".mpa":"video/mpeg" , ".mpc":"application/vnd.mpohun.certificate" , ".mpe":"video/mpeg" , ".mpeg":"video/mpeg" , ".mpg":"video/mpeg" , ".mpg4":"video/mp4" , ".mpga":"audio/mpeg" , ".mpn":"application/vnd.mophun.application" , ".mpp":"application/vnd.ms-project" , ".mps":"application/x-mapserver" , ".mpv2":"video/mpeg" , ".mrl":"text/x-mrml" , ".mrm":"application/x-mrm" , ".ms":"application/x-troff-ms" , ".msg":"application/vnd.ms-outlook" , ".mts":"application/metastream" , ".mtx":"application/metastream" , ".mtz":"application/metastream" , ".mvb":"application/x-msmediaview" , ".mzv":"application/metastream" , ".nar":"application/zip" , ".nbmp":"image/nbmp" , ".nc":"application/x-netcdf" , ".ndb":"x-lml/x-ndb" , ".ndwn":"application/ndwn" , ".nif":"application/x-nif" , ".nmz":"application/x-scream" , ".nokia-op-logo":"image/vnd.nok-oplogo-color" , ".npx":"application/x-netfpx" , ".nsnd":"audio/nsnd" , ".nva":"application/x-neva1" , ".nws":"message/rfc822" , ".oda":"application/oda" , ".ogg":"audio/ogg" , ".oom":"application/x-AtlasMate-Plugin" , ".p10":"application/pkcs10" , ".p12":"application/x-pkcs12" , ".p7b":"application/x-pkcs7-certificates" , ".p7c":"application/x-pkcs7-mime" , ".p7m":"application/x-pkcs7-mime" , ".p7r":"application/x-pkcs7-certreqresp" , ".p7s":"application/x-pkcs7-signature" , ".pac":"audio/x-pac" , ".pae":"audio/x-epac" , ".pan":"application/x-pan" , ".pbm":"image/x-portable-bitmap" , ".pcx":"image/x-pcx" , ".pda":"image/x-pda" , ".pdb":"chemical/x-pdb" , ".pdf":"application/pdf" , ".pfr":"application/font-tdpfr" , ".pfx":"application/x-pkcs12" , ".pgm":"image/x-portable-graymap" , ".pict":"image/x-pict" , ".pko":"application/ynd.ms-pkipko" , ".pm":"application/x-perl" , ".pma":"application/x-perfmon" , ".pmc":"application/x-perfmon" , ".pmd":"application/x-pmd" , ".pml":"application/x-perfmon" , ".pmr":"application/x-perfmon" , ".pmw":"application/x-perfmon" , ".png":"image/png" , ".pnm":"image/x-portable-anymap" , ".pnz":"image/png" , ".pot,":"application/vnd.ms-powerpoint" , ".ppm":"image/x-portable-pixmap" , ".pps":"application/vnd.ms-powerpoint" , ".ppt":"application/vnd.ms-powerpoint" , ".pptx":"application/vnd.openxmlformats-officedocument.presentationml.presentation" , ".pqf":"application/x-cprplayer" , ".pqi":"application/cprplayer" , ".prc":"application/x-prc" , ".prf":"application/pics-rules" , ".prop":"text/plain" , ".proxy":"application/x-ns-proxy-autoconfig" , ".ps":"application/postscript" , ".ptlk":"application/listenup" , ".pub":"application/x-mspublisher" , ".pvx":"video/x-pv-pvx" , ".qcp":"audio/vnd.qcelp" , ".qt":"video/quicktime" , ".qti":"image/x-quicktime" , ".qtif":"image/x-quicktime" , ".r3t":"text/vnd.rn-realtext3d" , ".ra":"audio/x-pn-realaudio" , ".ram":"audio/x-pn-realaudio" , ".rar":"application/octet-stream" , ".ras":"image/x-cmu-raster" , ".rc":"text/plain" , ".rdf":"application/rdf+xml" , ".rf":"image/vnd.rn-realflash" , ".rgb":"image/x-rgb" , ".rlf":"application/x-richlink" , ".rm":"audio/x-pn-realaudio" , ".rmf":"audio/x-rmf" , ".rmi":"audio/mid" , ".rmm":"audio/x-pn-realaudio" , ".rmvb":"audio/x-pn-realaudio" , ".rnx":"application/vnd.rn-realplayer" , ".roff":"application/x-troff" , ".rp":"image/vnd.rn-realpix" , ".rpm":"audio/x-pn-realaudio-plugin" , ".rt":"text/vnd.rn-realtext" , ".rte":"x-lml/x-gps" , ".rtf":"application/rtf" , ".rtg":"application/metastream" , ".rtx":"text/richtext" , ".rv":"video/vnd.rn-realvideo" , ".rwc":"application/x-rogerwilco" , ".s3m":"audio/x-mod" , ".s3z":"audio/x-mod" , ".sca":"application/x-supercard" , ".scd":"application/x-msschedule" , ".sct":"text/scriptlet" , ".sdf":"application/e-score" , ".sea":"application/x-stuffit" , ".setpay":"application/set-payment-initiation" , ".setreg":"application/set-registration-initiation" , ".sgm":"text/x-sgml" , ".sgml":"text/x-sgml" , ".sh":"application/x-sh" , ".shar":"application/x-shar" , ".shtml":"magnus-internal/parsed-html" , ".shw":"application/presentations" , ".si6":"image/si6" , ".si7":"image/vnd.stiwap.sis" , ".si9":"image/vnd.lgtwap.sis" , ".sis":"application/vnd.symbian.install" , ".sit":"application/x-stuffit" , ".skd":"application/x-Koan" , ".skm":"application/x-Koan" , ".skp":"application/x-Koan" , ".skt":"application/x-Koan" , ".slc":"application/x-salsa" , ".smd":"audio/x-smd" , ".smi":"application/smil" , ".smil":"application/smil" , ".smp":"application/studiom" , ".smz":"audio/x-smd" , ".snd":"audio/basic" , ".spc":"application/x-pkcs7-certificates" , ".spl":"application/futuresplash" , ".spr":"application/x-sprite" , ".sprite":"application/x-sprite" , ".sdp":"application/sdp" , ".spt":"application/x-spt" , ".src":"application/x-wais-source" , ".sst":"application/vnd.ms-pkicertstore" , ".stk":"application/hyperstudio" , ".stl":"application/vnd.ms-pkistl" , ".stm":"text/html" , ".svg":"image/svg+xml" , ".sv4cpio":"application/x-sv4cpio" , ".sv4crc":"application/x-sv4crc" , ".svf":"image/vnd" , ".svg":"image/svg+xml" , ".svh":"image/svh" , ".svr":"x-world/x-svr" , ".swf":"application/x-shockwave-flash" , ".swfl":"application/x-shockwave-flash" , ".t":"application/x-troff" , ".tad":"application/octet-stream" , ".talk":"text/x-speech" , ".tar":"application/x-tar" , ".taz":"application/x-tar" , ".tbp":"application/x-timbuktu" , ".tbt":"application/x-timbuktu" , ".tcl":"application/x-tcl" , ".tex":"application/x-tex" , ".texi":"application/x-texinfo" , ".texinfo":"application/x-texinfo" , ".tgz":"application/x-compressed" , ".thm":"application/vnd.eri.thm" , ".tif":"image/tiff" , ".tiff":"image/tiff" , ".tki":"application/x-tkined" , ".tkined":"application/x-tkined" , ".toc":"application/toc" , ".toy":"image/toy" , ".tr":"application/x-troff" , ".trk":"x-lml/x-gps" , ".trm":"application/x-msterminal" , ".tsi":"audio/tsplayer" , ".tsp":"application/dsptype" , ".tsv":"text/tab-separated-values" , ".ttf":"application/octet-stream" , ".ttz":"application/t-time" , ".txt":"text/plain" , ".uls":"text/iuls" , ".ult":"audio/x-mod" , ".ustar":"application/x-ustar" , ".uu":"application/x-uuencode" , ".uue":"application/x-uuencode" , ".vcd":"application/x-cdlink" , ".vcf":"text/x-vcard" , ".vdo":"video/vdo" , ".vib":"audio/vib" , ".viv":"video/vivo" , ".vivo":"video/vivo" , ".vmd":"application/vocaltec-media-desc" , ".vmf":"application/vocaltec-media-file" , ".vmi":"application/x-dreamcast-vms-info" , ".vms":"application/x-dreamcast-vms" , ".vox":"audio/voxware" , ".vqe":"audio/x-twinvq-plugin" , ".vqf":"audio/x-twinvq" , ".vql":"audio/x-twinvq" , ".vre":"x-world/x-vream" , ".vrml":"x-world/x-vrml" , ".vrt":"x-world/x-vrt" , ".vrw":"x-world/x-vream" , ".vts":"workbook/formulaone" , ".wav":"audio/x-wav" , ".wax":"audio/x-ms-wax" , ".wbmp":"image/vnd.wap.wbmp" , ".wcm":"application/vnd.ms-works" , ".wdb":"application/vnd.ms-works" , ".web":"application/vnd.xara" , ".wi":"image/wavelet" , ".wis":"application/x-InstallShield" , ".wks":"application/vnd.ms-works" , ".wm":"video/x-ms-wm" , ".wma":"audio/x-ms-wma" , ".wmd":"application/x-ms-wmd" , ".wmf":"application/x-msmetafile" , ".wml":"text/vnd.wap.wml" , ".wmlc":"application/vnd.wap.wmlc" , ".wmls":"text/vnd.wap.wmlscript" , ".wmlsc":"application/vnd.wap.wmlscriptc" , ".wmlscript":"text/vnd.wap.wmlscript" , ".wmv":"audio/x-ms-wmv" , ".wmx":"video/x-ms-wmx" , ".wmz":"application/x-ms-wmz" , ".wpng":"image/x-up-wpng" , ".wps":"application/vnd.ms-works" , ".wpt":"x-lml/x-gps" , ".wri":"application/x-mswrite" , ".wrl":"x-world/x-vrml" , ".wrz":"x-world/x-vrml" , ".ws":"text/vnd.wap.wmlscript" , ".wsc":"application/vnd.wap.wmlscriptc" , ".wv":"video/wavelet" , ".wvx":"video/x-ms-wvx" , ".wxl":"application/x-wxl" , ".x-gzip":"application/x-gzip" , ".xaf":"x-world/x-vrml" , ".xar":"application/vnd.xara" , ".xbm":"image/x-xbitmap" , ".xdm":"application/x-xdma" , ".xdma":"application/x-xdma" , ".xdw":"application/vnd.fujixerox.docuworks" , ".xht":"application/xhtml+xml" , ".xhtm":"application/xhtml+xml" , ".xhtml":"application/xhtml+xml" , ".xla":"application/vnd.ms-excel" , ".xlc":"application/vnd.ms-excel" , ".xll":"application/x-excel" , ".xlm":"application/vnd.ms-excel" , ".xls":"application/vnd.ms-excel" , ".xlsx":"application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" , ".xlt":"application/vnd.ms-excel" , ".xlw":"application/vnd.ms-excel" , ".xm":"audio/x-mod" , ".xml":"text/plain", ".xml":"application/xml", ".xmz":"audio/x-mod" , ".xof":"x-world/x-vrml" , ".xpi":"application/x-xpinstall" , ".xpm":"image/x-xpixmap" , ".xsit":"text/xml" , ".xsl":"text/xml" , ".xul":"text/xul" , ".xwd":"image/x-xwindowdump" , ".xyz":"chemical/x-pdb" , ".yz1":"application/x-yz1" , ".z":"application/x-compress" , ".zac":"application/x-zaurus-zac" , ".zip":"application/zip" , ".json":"application/json" }

json文件

3、模塊之間的調用web

例子一：正則表達式

首先咱們在work directory中創建一個test文件夾，在其中新建兩個文件，bar.js，foo.js，文件內容分別以下：npm

bar.js:

1 console.log("我是bar");

foo.js:

 1 var bar = require("./bar.js");  2 var msg = "你好";  3 var info = "呵呵";  4 
 5 function showInfo(){  6  console.log(info);  7 }  8 
 9 exports.msg = msg; 10 exports.info = info; 11 exports.showInfo = showInfo;

測試程序：

1 var foo = require("./test/foo.js");
2 console.log(foo.msg); 3 console.log(foo.info); 4 foo.showInfo();

在這個簡單的程序中，咱們能夠看到從主程序執行，首先引用foo.js在引用的時候就執行該js的代碼，而執行foo的時候第一句又是一個require，這個時候就會找到bar.js來執行，結果就是輸出一串字符串，而後就沒有了，藉着主程序開始執行第二行，由於foo中已經暴露了相應的接口，因此能夠訪問其中的對象和方法，因此輸出相應的內容。在這裏咱們要注意，一、require的過程其實也是一種執行的過程；二、模塊之間經過exports來暴露接口，而且經過require來使用，這就給咱們編程帶來了極大的方便。程序運行的結果是：

例子二：

暴露一個類：

People.js：

 1 function People(name,sex,age){  2     this.name = name;  3     this.sex = sex;  4     this.age = age;  5 }  6 People.prototype = {  7     sayHello : function(){  8         console.log(this.name + "   "+this.sex +"   " + this.age);  9  } 10 } 11 //此時，People就被視爲構造函數，能夠用new來實例化了。
12 module.exports = People;

主程序：

1 var People = require("./test/People.js"); 2 var xiaoming = new People("小明","男","12"); 3 xiaoming.sayHello(); 4 console.log(xiaoming.age); 5 console.log(xiaoming.sex);

這裏注意暴露一個類使用的是module.exports，經過把類賦值給該變量既能夠在主程序中生成對象了，這點很是方便。執行結果爲：

例子三：

在node.js中若是將js文件放到node_modules文件夾下，那麼咱們就能夠不用寫路徑名來直接引用，由於系統會本身找到該文件夾而且從中找到咱們對應的文件。

咱們在主程序中，用下面的代碼來執行，能夠看到輸出的結果爲：

1 var foo = require("foo.js");  //沒有寫./
2 console.log(foo.msg);

用var foo = require("bar.js"); //沒有寫./來測試結果爲：

例子四：文件夾中引用，以下圖所示，在node_modules中創建了一個文件夾，在文件夾中用了package.json來定義該文件夾下的執行文件的入口是app.js，所以咱們就能夠在主程序中直接調用該文件夾來執行相應的文件了，執行結果以下：

主程序：

1 var bar = require("bar");  //在引用一個文件夾
2 console.log(bar.msg);

例子五：

一樣的，在node.js世界中，由於有npm(node.js package manager)的存在,咱們可使用別人的代碼，在命令行中咱們能夠直接使用npm install 包名來從網上下載相應的包到本地的node_modules中使用，也可使用npm install命令來本身配置package.json文件從而自行下載相應的文件，這兩種方法都是有效可行的！

1 var sd = require("silly-datetime"); 2 var ttt = sd.format(new Date(), 'YYYYMMDDHHmm'); 3 console.log(ttt);

4、路由的剝離

首先咱們看一個程序：

 1 var http = require("http");  2 var router = require("./router.js");  3 
 4 //建立服務器
 5 var server = http.createServer(function(req,res){  6     if(req.url == "/"){  7  router.showIndex(req,res);  8     }else if(req.url.substr(0,9) == "/student/"){  9  router.showStudent(req,res); 10     }else{ 11  router.show404(req,res); 12  } 13 }); 14 server.listen(3100,"127.0.0.1");

router.js:

 1 exports.showIndex = showIndex;  2 exports.showStudent = showStudent;  3 exports.show404 = show404;  4 
 5 function showIndex(req,res){  6     res.writeHead(200,{"Content-Type":"text/html;charset=UTF8"});  7     res.end("我是首頁");  8 }  9 
10 function showStudent(req,res){ 11     var id = req.url.substr(9,6); 12     res.writeHead(200,{"Content-Type":"text/html;charset=UTF8"}); 13     res.end("我是學生頁面" + id); 14 } 15 
16 function show404(req,res){ 17     res.writeHead(404,{"Content-Type":"text/html;charset=UTF8"}); 18     res.end("404"); 19 }

在這個程序裏，咱們將路由的具體處理過程拋給了相應的處理程序，而後用模塊調用的方式來完成了導航功能，大大的簡化了咱們的代碼，增長了代碼的清晰度。

5、post請求提交

首先咱們新建一個html，包含有表單，咱們經過表單來提交數據。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
    <form action="dopost" method="post" enctype="multipart/form-data">
        <p> 姓名 ： <input type="text" name="name">
        </p>
        <p> 性別 ： <input type="radio" name="sex" value="男">男 <input type="radio" name="sex" value="女">女 </p>
        <p> 愛好： <input type="checkbox" name="hobby" value="睡覺" />睡覺 <input type="checkbox" name="hobby" value="吃飯" />吃飯 <input type="checkbox" name="hobby" value="足球" />足球 </p>
        <p> 圖片： <input type="file" name="tupian" />
        </p>
        <p>
            <input type="submit" />
        </p>
    </form>
</body>
</html>

View Code

服務器代碼：

 1 var http = require("http");  2 var querystring = require("querystring");  3 //建立服務器
 4 var server = http.createServer(function(req,res){  5     //若是你的訪問地址是這個，而且請求類型是post
 6     if(req.url == "/dopost" && req.method.toLowerCase() == "post"){  7         var urlstr="";  8         req.addListener("data",function(postdata){  9             urlstr+=postdata;    //接收到的表單數據字符串
10             var jsondata = querystring.parse(urlstr);        //轉換成json對象
11             var decodedata = decodeURIComponent(urlstr);        //對錶單數據進行解碼
12             console.log("原數據（加密數據）：  "+urlstr); 13             console.log("json數據（轉換成對象）： "); 14  console.log(jsondata); 15             console.log("解碼數據：  "+decodedata); 16             urlstr = decodedata; 17  }); 18         req.addListener("end",function(){ 19             res.writeHead(200,{"Content-Type":"text/plain; charset=utf-8"}); 20  res.write(urlstr); 21  res.end(); 22  }); 23  } 24 }); 25 server.listen(3100,"127.0.0.1");

運行結果：

上面的代碼，是網上廣爲流傳的代碼，我想不少人並無實踐過，而是隻從書上抄過來的，豈不知在如今的編譯器中早就行不通了，爲何呢，一個事情的發生一定有其緣由，咱們原本是想獲得含有鍵值對的有效地json數據，但是咱們如今獲得了什麼，只是一些描述符下面包含的咱們輸入的有效信息，爲何會這樣呢？！這個問題花費了我很長時間，總算找到了緣由，其實咱們的思路並沒錯，只不過瀏覽器傳遞過來的數據，對於每個字段都作了描述，正如咱們看到的這些不知道什麼意思的數字，還有回車符等，傳統的方法是解決不了的，我在網上搜了不少解決辦法，最後發現這個東西在如今的node.js版本中就是這樣的，咱們的方法並沒錯，經過異步的方法，從事件中不斷地累加咱們的數據，data事件讓咱們收到全部的數據，而數據收完以後就會觸發end方法讓咱們對數據進行處理，所以在這裏咱們不該該只是簡單的接收到數據，而應該對那麼長的一段字符串進行解析，也就是返回瀏覽器的那些數據，這些字段的修飾是頗有規律的，所以咱們可使用正則表達式或者字符串的遍歷的方法（數據清洗）從這些無序的數據中抽取出咱們須要的信息，而後構成鍵值對而且返回，這是惟一正確的方法，在原生的接收數據的方法中這是很是可取的，不過代碼和工做量將大大的激增，那麼有沒有更好的解決辦法呢，由於生活中咱們常常遇到這樣的例子，好比說咱們申請國獎國勵的時候，常常須要在網上填寫信息，而後post過去，若是這個問題解決不了，除非咱們不使用nodejs了，可是也會遇到其餘的問題，所以，在node.js中不僅咱們遇到這樣的問題，所以就會有不少人有相應的解決辦法，好比說formidable這個npm共享資源的有機組成部分就是解決這個問題的，使用也很是的簡單！

方法二：formidable

首先咱們download這個module：

而後咱們運行服務器：

 1 var http = require("http");  2 var formidable = require('formidable');  3 var util = require("util");  4 var server = http.createServer(function(req,res){  5     if(req.url == "/dopost" && req.method.toLowerCase() == "post"){  6         //Creates a new incoming form.
 7         var form = new formidable.IncomingForm();  8         //設置文件上傳存放地址
 9         form.uploadDir = "./uploads"; 10         //執行裏面的回調函數的時候，表單已經所有接收完畢了。
11         form.parse(req, function(err, fields, files) { 12             if(err){ 13                 throw err; 14  } 15  console.log(fields); 16  console.log(files); 17  console.log(util.inspect({fields: fields, files: files})); 18             //全部的文本域、單選框，都在fields存放；
19             //全部的文件域，files
20             res.writeHead(200, {'content-type': 'text/plain'}); 21             res.end("成功"); 22  }); 23  } 24 }); 25 
26 server.listen(3100,"127.0.0.1");

運行結果：

更無限強大的是，咱們居然獲得瞭如此詳細的信息，json數據也早就有了，並且咱們還能夠上傳文件，好比說圖片，文檔等，這是多麼厲害的一種技術呀，從這裏能夠看到咱們從開源的社區找到別人用心寫好的具備很強的魯棒性的產品而且拿來爲本身所用是多麼的重要和有意義，從另外一方面也說明了資源的共享是多麼的重要！

上傳一張圖片看看：

添加擴展名以後：

到這裏爲止，咱們能夠看到formidable的強大之處了，只是美中不足的是，上傳的圖片沒有擴展名，而且是自動生成的文件名，所以咱們下面能夠對文件進行更名，這樣咱們就能夠實現更好的效果和用戶體驗了！！！

代碼以下：

 1 var http = require("http");  2 var formidable = require('formidable');  3 var util = require("util");  4 var fs = require("fs");  5 var sd = require("silly-datetime");  6 var path = require("path");  7 var server = http.createServer(function(req,res){  8     if(req.url == "/dopost" && req.method.toLowerCase() == "post"){  9         //Creates a new incoming form.
10         var form = new formidable.IncomingForm(); 11         //設置文件上傳存放地址
12         form.uploadDir = "./uploads"; 13         //執行裏面的回調函數的時候，表單已經所有接收完畢了。
14         form.parse(req, function(err, fields, files) { 15             if(err){ 16                 throw err; 17  } 18             //console.log(util.inspect({fields: fields, files: files}));
19             //時間，使用第三方模塊，silly-datetime
20             var ttt = sd.format(new Date(), 'YYYYMMDDHHmmss'); 21             var ran = parseInt(Math.random() * 89999 + 10000); 22             var extname = path.extname(files.tupian.name); 23             //執行更名
24             var oldpath = __dirname + "/" + files.tupian.path; 25             //新的路徑由三個部分組成：時間戳、隨機數、拓展名
26             var newpath = __dirname + "/uploads/" + ttt + ran + extname; 27 
28             //更名
29             fs.rename(oldpath,newpath,function(err){ 30                 if(err){ 31                     throw Error("更名失敗"); 32  } 33                 res.writeHead(200, {'content-type': 'text/plain'}); 34                 res.end("成功"); 35  }); 36  }); 37     }else if(req.url == "/"){ 38         //呈遞form.html頁面
39         fs.readFile("./form.html",function(err,data){ 40             res.writeHead(200, {'content-type': 'text/html'}); 41  res.end(data); 42  }) 43     }else{ 44         res.writeHead(404, {'content-type': 'text/html'}); 45         res.end("404"); 46  } 47 }); 48 server.listen(3100,"127.0.0.1");

運行結果可知，咱們的程序成功的將圖片名改爲了本身想要的格式，而且基本上不會重複，適合高併發訪問！！！

6、模板引擎ejs

最後讓咱們看一下模板引擎，首先咱們仍是下載ejs:

而後是代碼：

 1 var ejs = require("ejs");  2 //模板
 3 var string = "好高興啊，今天我買了iphone<%= a %>s";  4 //數據
 5 var data = {  6     a : 8
 7 };  8 //數據綁定
 9 var html = ejs.render(string, data); 10 //輸出
11 console.log(html);

結果：能夠看到咱們成功的實現了綁定！根據這一特性咱們能夠實現更好的效果。

高級版：

 1 var ejs = require("ejs");  2 var fs = require("fs");  3 var http = require("http");  4 var server = http.createServer(function(req,res){  5     fs.readFile("./views/index.ejs",function(err,data){  6         //綁定模板
 7         var template = data.toString();  8         var dictionary = {  9             a:7, 10  news : [ 11                 {"title":"第一條新聞","count":10}, 12                 {"title":"第二條新聞","count":20}, 13                 {"title":"第三條新聞","count":30} 14  ] 15  }; 16         var html = ejs.render(template,dictionary); 17         //顯示
18         res.writeHead(200,{"Content-Type":"text/html;charset=UTF8"}); 19  res.end(html); 20  }); 21 }); 22 
23 server.listen(3100,"127.0.0.1");

index.ejs:

 1 <!doctype html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title></title>
 6 </head>
 7 <body>
 8 <h1>好高興啊，今天我買了一個iphone<%= a %>s</h1>
 9 <ul>
10     <%
11     for(var i = 0 ; i < news.length ; i++){ 12     if(news[i].count > 15){ 13     %>
14     <li><%= news[i].title %></li>
15     <%
16  } 17  } 18     %>
19 </ul>
20 </body>
21 </html>

運行結果：爲咱們編寫大型程序奠基了基礎！！！

7、總結

呼，好長的一篇文章呀，中間斷斷續續，加上其餘的事情，一直寫了一個星期了，能寫完真的不容易，裏面的不少技術，都是最底層的東西，這樣由淺入深的學習才能按部就班，其實到了這個地方，咱們徹底能夠放手去寫一些大型的工程了，由於咱們已經具有了良好的基礎，有了B/S之間通訊的基礎，這些都是咱們能夠仰仗的資本，最重要的是咱們可使用npm這個強大到使人望其項背的神器，咱們也能夠在上面投放屬於咱們本身的模塊，造福於其餘人！！！若是您看到了這個地方，那您必定是一個比較勤奮的人，而且想學一些東西，對於寫文章，我一直都是處於一種興趣和熱情，確定有些許的疏漏之處，還請多多指出，但願個人文章能夠幫助到那些樂於學習，樂於奉獻的人，謝謝！！！！！！

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