[英]Trouble Getting JSON Data
我对使用JavaScript进行后端编程非常陌生,并且已经编写了一些代码来查询数据库并将结果返回为JSON。 它似乎在浏览器中正常工作,但是我的iOS代码没有从中获取任何数据。 我现在在测试时在本地运行它。 如果您查看我的Swift来从URL获取数据,那么我将从捕获中的print语句获取NO JSON。
JavaScript的
'use strict';
var util = require('util');
var sql = require("mssql");
var express = require('express');
var port = process.env.PORT || 1337;
var membershipNumber;
var queryString;
var app = express();
app.get('/membership/:number', function (req, res) {
console.log("\nPARAMS:");
console.log(req.params.number);
membershipNumber = req.params.number;
queryString = util.format('SELECT major_key, company, status, paid_thru FROM name WHERE major_key = \'%s\' and member_record = 1', membershipNumber);
console.log("\nQUERY:");
console.log(queryString);
res.setHeader('Content-Type', 'application/json');
res.set('Content-Type', 'application/json');
membershipStatusQuery(queryString, res);
});
app.get('/', function (req, res) {
var dictionary = [];
dictionary.push({
key: "none"
});
var jsonDict = JSON.stringify(dictionary);
res.setHeader('Content-Type', 'application/json');
res.set('Content-Type', 'application/json');
res.send(jsonDict);
});
function membershipStatusQuery(query, response) {
var config = {
server: 'DB_Server',
database: 'testDB',
user: 'sa',
password: 'password',
port: 1433
};
var connection = new sql.Connection(config);
connection.connect().then(function () {
var req = new sql.Request(connection);
req.query(query).then(function (recordset) {
connection.close();
response.send(results);
})
.catch(function (err) {
console.log(err);
connection.close();
response.send(err);
});
})
.catch(function (err) {
console.log(err);
response.send(err);
});
}
app.listen(port, function () {
console.log("Listening on port %s", port);
});
结果
[{"major_key":"0001354648","company":"Membership of David Metzgar","status":"A","paid_thru":"2017-10-31T00:00:00.000Z"}]
iOS Swift代码类从URL获取JSON:
import UIKit
class GetJSON: NSObject {
func getJSONFrom(urlString: String) -> JSON {
let url = URL(string: urlString)
var data = Data()
do {
data = try Data(contentsOf: url!)
} catch {
print("No JSON")
// TODO: Display error
}
let json = JSON(data: data)
return json
}
}
来自另一个类的使用JSON的方法:
func getQueryResultsJSON() {
print("http://localhost:1337/membership/\(memberNumberTextField.text!)")
// let jsonURL = "http://localhost:1337/membership/\(memberNumberTextField.text!)"
let jsonURL = "http://localhost:1337/membership/0001354648"
let getJSON = GetJSON()
self.resultsArray = getJSON.getJSONFrom(urlString: jsonURL)
if let dictionary = resultsArray?[0].dictionaryObject {
if let status = dictionary["status"] {
if status as! String == "A" {
print(dictionary)
print("Provided membership is active")
// membership is active
// TODO: save info and display membership card
} else {
print(dictionary)
print("Provided membership is NOT active")
// membership is not active
// TODO: display alert
}
} else {
print("DOESN'T EXIST!")
// membership number does not exist
// TODO: display alert
}
} else {
print("NOTHING!")
}
}
let url = NSURL(string: "your url")!
let request = NSMutableURLRequest(url: url as URL)
// request.httpMethod = "POST"
// request.httpBody = jsonData
//request.setValue("application/json; charset=utf-8", forHTTPHeaderField: "Content-Type")
let task = URLSession.shared.dataTask(with: request as URLRequest){ data,response,error in
if error != nil {
return
}
do {
let userObject = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [String: String]
if userObject != nil {
// do something
}
} catch let jsonError {
print(jsonError)
print(String(data: data!, encoding: String.Encoding.utf8)!)
}
}
task.resume()
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