遇到一个奇怪的问题。一直在寻找答案,但一无所获。我正在做一个 Node api 教程,当我执行任何 GET 请求时,它会从我的终端中的 mongoDB 数据库返回 JSON,但在我的浏览器或 postman 中我什么也没有得到,只有在终端中我才得到任何响应。当我在 postman 中尝试 POST 时,它说无法连接到后端。
这是我的代码:
var http = require('http');
var url = require('url');
var database = require('./database');
// Generic find methods (GET)
function findAllResources(resourceName, req, res) {
database.find('OrderBase', resourceName, {}, function (err, resources) {
res.writeHead(200, {'Content-Type': 'application/json'});
res.end(JSON.stringify(resources));
});
};
var findResourceById = function (resourceName, id, req, res) {
database.find('OrderBase', resourceName, {'_id': id}, function (err, resource) {
res.writeHead(200, {'Content-Type': 'application/json'});
res.end(JSON.stringify(resource));
});
};
// Product methods
var findAllProducts = function (req, res) {
findAllResources('Products', req, res);
};
var findProductById = function (id, req, res) {
findResourceById('Products', id, req, res);
};
// Generic insert/update methods (POST, PUT)
var insertResource = function (resourceName, resource, req, res) {
database.insert('OrderBase', resourceName, resource, function (err, resource) {
res.writeHead(200, {'Content-Type': 'application/json'});
res.end(JSON.stringify(resource));
});
};
// Product methods
var insertProduct = function (product, req, res) {
insertResource('OrderBase', 'Product', product, function (err, result) {
res.writeHead(200, {'Content-Type': 'application/json'});
res.end(JSON.stringify(result));
});
};
var server = http.createServer(function (req, res) {
// Break down the incoming URL into its components
var parsedURL = url.parse(req.url, true);
// determine a response based on the URL
switch (parsedURL.pathname) {
case '/api/products':
if (req.method === 'GET') {
// Find and return the product with the given id
if (parsedURL.query.id) {
findProductById(id, req, res)
}
// There is no id specified, return all products
else {
findAllProducts(req, res);
}
}
else if (req.method === 'POST') {
//Extract the data stored in the POST body
var body = '';
req.on('data', function (dataChunk) {
body += dataChunk;
});
req.on('end', function () {
// Done pulling data from the POST body.
// Turn it into JSON and proceed to store it in the database.
var postJSON = JSON.parse(body);
insertProduct(postJSON, req, res);
});
}
break;
default:
res.end('You shall not pass!');
}
});
server.listen(8080);
console.log('Up and running, ready for action!');
最佳答案
您有多个以 err
作为第一个参数的回调,但您没有处理任何潜在的错误。这意味着如果出现问题,您不会捕获它并返回错误。我不知道这是否与此有关,但作为一种实践(甚至不是“最佳”,而是一般实践)而不是这样做
function (err, resource) {
res.writeHead(200, {'Content-Type': 'application/json'});
res.end(JSON.stringify(resource));
}
这样做
function (err, resource) {
if(err){
// do something to warn the client and stop here
}
res.writeHead(200, {'Content-Type': 'application/json'});
res.end(JSON.stringify(resource));
}
尝试一下,在尝试输出答案之前看看是否确实遇到了错误。
关于javascript - Node.js API 在终端中返回 JSON,但在浏览器中不返回,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/35786896/