2012-09-29 157 views
23

我剛開始在我的大學課程中使用node.js和json對象。本週我們的任務之一是創建一些json對象並將對象的部分提取到html頁面中。我想我對如何做到這一點有很好的把握,但是當我嘗試啓動節點時,我遇到了一個錯誤。如果我刪除了大學對象和解析語句,那麼節點運行良好。JSON + Node.js - 意外的令牌

這裏是我的錯誤,當我運行「節點index.js」:

undefined:1 
[object Object],[object Object],[object Object],[object Object],[object Object 
^ 
SyntaxError: Unexpected token o 
at Object.parse (native) 
at Object.<anonymous> (/home/ubuntu/node_stuff/node_json/requestHandlers.js:13:20) 
at Module._compile (module.js:449:26) 
at Object.Module._extensions..js (module.js:467:10) 
at Module.load (module.js:356:32) 
at Function.Module._load (module.js:312:12) 
at Module.require (module.js:362:17) 
at require (module.js:378:17) 
at Object.<anonymous> (/home/ubuntu/node_stuff/node_json/index.js:3:23) 
at Module._compile (module.js:449:26) 

這裏是我一起工作的代碼。

var querystring = require("querystring"), 
fs = require("fs"), 
formidable = require("formidable"); 

var colleges = [ 
{"name":"A-B Tech","street":"340 Victoria Road","city":"Asheville","state":"NC","zip":"28801","phone":"828-254-1921"}, 
{"name":"UNC Asheville","street":"1 University Heights","city":"Asheville","state":"NC","zip":"28804","phone":"828-251-6600"}, 
{"name":"UNC Charlotte","street":"9201 University City Blvd","city":"Charlotte","state":"NC","zip":"28223","phone":"704-687-8622"}, 
{"name":"Western Carolina","street":"North Carolina 107","city":"Cullowhee","state":"NC","zip":"28723","phone":"877-928-4968"}, 
{"name":"NC State","street":"2200 Hillsborough","city":"Raleigh","state":"NC","zip":"27695","phone":"919-515-2011"} 
]; 

var college = JSON.parse(colleges); 

function abtech(response) { 
console.log("Request handler 'abtech' was called."); 

var body = '<html>'+ 
'<head>'+ 
'<meta http-equiv="Content-Type" '+ 
'content="text/html; charset=UTF-8" />'+ 
'</head>'+ 
'<body>'+ 
'<ul>'+ 
'<li>' + college[0].name + '</li>'+ 
'<li>' + college[0].street + '</li>'+ 
'<li>' + college[0].city + ' ' + college[0].state + ' ' + college[0].zip + '</li>'+ 
'<li>' + college[0].phone + '</li>'+ 
'</ul>'+ 
'</body>'+ 
'</html>'; 

response.writeHead(200, {"Content-Type": "text/html"}); 
response.write(body); 
response.end(); 
} 

function unca(response) { 
console.log("Request handler 'abtech' was called."); 

var body = '<html>'+ 
'<head>'+ 
'<meta http-equiv="Content-Type" '+ 
'content="text/html; charset=UTF-8" />'+ 
'</head>'+ 
'<body>'+ 
'<ul>'+ 
'<li></li>'+ 
'<li></li>'+ 
'<li></li>'+ 
'<li></li>'+ 
'</ul>'+ 
'</body>'+ 
'</html>'; 

response.writeHead(200, {"Content-Type": "text/html"}); 
response.write(body); 
response.end(); 
} 

function home(response) { 
console.log("Request handler 'home' was called."); 

var body = '<html>'+ 
'<head>'+ 
'<meta http-equiv="Content-Type" '+ 
'content="text/html; charset=UTF-8" />'+ 
'</head>'+ 
'<body>'+ 
'<h1>Welcome to College</h2>'+ 
'<p>Where would you like to visit?</p>'+ 
'<ul>'+ 
'<li><a href="/colleges">Colleges</a></li>'+ 
'<li><a href="/hours">Hours of Operation</a></li>'+ 
'<li><a href="/start">Upload a Photo</a></li>'+ 
'<li><a href="/show">View Gallery</a></li>'+ 
'</ul>'+ 
'</body>'+ 
'</html>'; 

response.writeHead(200, {"Content-Type": "text/html"}); 
response.write(body); 
response.end(); 
} 

function colleges(response) { 
console.log("Request handler 'colleges' was called."); 

var body = '<html>'+ 
'<head>'+ 
'<meta http-equiv="Content-Type" '+ 
'content="text/html; charset=UTF-8" />'+ 
'</head>'+ 
'<body>'+ 
'<h1>Colleges</h2>'+ 
'<ul>'+ 
'<li><a href="/abtech">A-B Tech</a></li>'+ 
'<li><a href="/unca">UNC Asheville</a></li>'+ 
'<li><a href="/uncc">UNC Charlotte</a></li>'+ 
'<li><a href="/wcu">Western Carolina</a></li>'+ 
'<li><a href="/ncsu">NC State</a></li>'+ 
'</ul>'+ 
'</body>'+ 
'</html>'; 

response.writeHead(200, {"Content-Type": "text/html"}); 
response.write(body); 
response.end(); 
} 

function hours(response) { 
console.log("Request handler 'gallery' was called."); 

var body = '<html>'+ 
'<head>'+ 
'<meta http-equiv="Content-Type" '+ 
'content="text/html; charset=UTF-8" />'+ 
'</head>'+ 
'<body>'+ 
'<h1>Hours of Operation</h2>'+ 
'<table>'+ 
'<tr><td>Monday - Thursday</td><td>9 a.m. - 7 p.m.</td></tr>'+ 
'<tr><td>Friday</td><td>9 a.m. - 5 p.m.</td></tr>'+ 
'<tr><td>Saturday</td><td>9 a.m. - 12 p.m.</td></tr>'+ 
'</table>'+ 
'</body>'+ 
'</html>'; 

response.writeHead(200, {"Content-Type": "text/html"}); 
response.write(body); 
response.end(); 
} 


function start(response) { 
console.log("Request handler 'start' was called."); 

var body = '<html>'+ 
'<head>'+ 
'<meta http-equiv="Content-Type" '+ 
'content="text/html; charset=UTF-8" />'+ 
'</head>'+ 
'<body>'+ 
'<h1>Upload a file</h2>'+ 
'<p>It will be shown on the /show url after</p>'+ 
'<form action="/upload" enctype="multipart/form-data" '+ 
'method="post">'+ 
'<input type="file" name="upload" multiple="multiple">'+ 
'<input type="submit" value="Upload file" />'+ 
'</form>'+ 
'</body>'+ 
'</html>'; 

response.writeHead(200, {"Content-Type": "text/html"}); 
response.write(body); 
response.end(); 
} 

function upload(response, request) { 
console.log("Request handler 'upload' was called."); 

var form = new formidable.IncomingForm(); 
console.log("about to parse"); 
form.parse(request, function(error, fields, files) { 
console.log("parsing done"); 

/* Possible error on Windows systems: 
    tried to rename to an already existing file */ 
fs.rename(files.upload.path, "/home/ubuntu/node_stuff/node_assignment/test.jpg", function(err) { 
    if (err) { 
    fs.unlink("/home/ubuntu/node_stuff/node_assignment/test.jpg") 
    fs.rename(files.upload.path, "/home/ubuntu/node_stuff/node_assignment/test.jpg"); 
    } 
}); 
response.writeHead(200, {"Content-Type": "text/html"}); 
response.write("received image:<br/>"); 
response.write("<img src='/show' />"); 
response.end(); 
}); 
} 

function show(response) { 
console.log("Request handler 'show' was called."); 
fs.readFile("/home/ubuntu/node_stuff/node_assignment/test.jpg", "binary", function(error, file) { 
if(error) { 
    response.writeHead(500, {"Content-Type": "text/plain"}); 
    response.write(error + "\n"); 
    response.end(); 
} else { 
    response.writeHead(200, {"Content-Type": "image/jpg"}); 
    response.write(file, "binary"); 
    response.end(); 
} 
}); 
} 

exports.start = start; 
exports.upload = upload; 
exports.show = show; 
exports.home = home; 
exports.colleges = colleges; 
exports.hours = hours; 
exports.abtech = abtech; 

任何有關我做錯了什麼暗示將非常感激。我的教練很難在週末休息,所以我沒有其他地方可以轉身。謝謝。

+1

總是一個好主意,用的typeof(yourVar);看看你在做什麼。許多框架(Express,Restify等)負責爲你解析JSON - 尤其是當它通過HTTP請求進入時 –

回答

28

您的colleges變量已經是一個有效的JavaScript對象。你不必使用JSON.parse就可以了。

JSON.parse預計String作爲第一個參數,但您提供了一個Object。因此它被強制爲一個String,看起來像您在錯誤消息中看到的那個。

爲了您的代碼的其餘部分,你可能想看看ExpressZappa要能寫代碼更緊湊一點;)

+0

謝謝Tharabas。沒有意識到我不需要解析語句。在課堂上展示他使用它,現在它工作得很好 我們將很快回顧Express和MongoDB。 –