currently developing a .net C# application which is showing a web browser. But since visual studio web browser is still using ie7 and does not support quite lots of things, I plan to put in the CefSharp which is the Chromium. So, have you guys every try get some json data from a localhost server using CefSharp? I have tried two ways to get it but failed.
For C# in Visual Studio, I fired the Chromium browser like this:
var test = new CefSharp.WinForms.ChromiumWebBrowser(AppDomain.CurrentDomain.BaseDirectory + "html\\index.html")
{
Dock = DockStyle.Fill,
};
this.Controls.Add(test);
Then for the index.html, it is require to get data from local host port 1000 after it loaded. I have tried two ways for the javascript:
First using XMLHttpRequest:
var xmlhttp = new XMLHttpRequest();
var url = "http://localhost:1000/api/data1";
var services;
xmlhttp.onreadystatechange = function () {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
services = jQuery.parseJSON(xmlhttp.responseText);
}
}
xmlhttp.open("GET", url, true);
xmlhttp.send();
Secondly using jquery's .get():
$.get("http://localhost:1000/api/data1", function (data) {
var services = data;
});
But both ways can't return the data. If I put the index.html into normal browser like Chrome or Firefox, I am able to get the data.
Is it something missing in my coding? Any ideas what's wrong guys?
I am using Chromium web browser and making GET request to localhost for JSON. Along with this i am running a webserver which keeps on listening and return JSON.
Webserver:
public class WebServer
{
public WebServer()
{
}
void Process(object o)
{
Thread thread = new Thread(() => new WebServer().Start());
thread.Start();
HttpListenerContext context = o as HttpListenerContext;
HttpListenerResponse response = context.Response;
try
{
string json;
string url = context.Request.Url.ToString();
if (url.Contains("http://localhost:8888/json"))
{
List<SampleObject> list = new List<SampleObject>();
json = JsonConvert.SerializeObject(new
{
results = list
});
byte[] decryptedbytes = new byte[0];
decryptedbytes = System.Text.Encoding.UTF8.GetBytes(json);
response.AddHeader("Content-type", "text/json");
response.ContentLength64 = decryptedbytes.Length;
System.IO.Stream output = response.OutputStream;
try
{
output.Write(decryptedbytes, 0, decryptedbytes.Length);
output.Close();
}
catch (Exception e)
{
response.StatusCode = 500;
response.StatusDescription = "Server Internal Error";
response.Close();
Console.WriteLine(e.Message);
}
}
}
catch (Exception ex)
{
response.StatusCode = 500;
response.StatusDescription = "Server Internal Error";
response.Close();
Console.WriteLine(ex);
}
}
static byte[] GetBytes(string str)
{
byte[] bytes = new byte[str.Length * sizeof(char)];
System.Buffer.BlockCopy(str.ToCharArray(), 0, bytes, 0, bytes.Length);
return bytes;
}
public void Start()
{
HttpListener server = new HttpListener();
server.Prefixes.Add("http://localhost:8888/json");
server.Start();
while (true)
{
ThreadPool.QueueUserWorkItem(Process, server.GetContext());
}
}
}
public class SampleObject
{
string param1 { get; set; }
string param2 { get; set; }
string param3 { get; set; }
}
To Start Webserver:
Thread thread = new Thread(() => new WebServer().Start());
thread.Start();
Index.html
<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script>
$(document).ready(function(){
$.get("http://localhost:8888/json", function (data) {
var jsonData= data;
});
});
</script>
</head>
<body>
<p>Example JSON Request.</p>
</body>
</html>
Before launching Index.html inside Chromium web browser, start running webserver to listen for requests. After document load event it makes a ajax call, then it hits the Webserver then Webserver returns JSON. You can test it using Chrome also. Start webserver and type the URL(http://localhost:8888/json) in address bar you will see returned JSON in Developers tools.
Note: Code is not tested. Hope it will work.
Related
I created a service to download a PDF file.
On my server-side(Java) the PDF is generated successfully. But I am unable to download that on the UI side (Using Jquery Ajax call).
Could anyone please help me with this?
$(document).on('click', '.orderView', function(event){
orderId = $(this).attr('data');
$.ajax({
type : 'GET',
contentType : 'application/json',
url : '../service/purchase/generateInventoryPurchasePdf/'+orderId,
success : function(response) {
console.log("Success");
},
error : function(response) {
console.log("Error :" + response);
}
});
});
Java Code:
#RequestMapping(value = "/generateInventoryPurchasePdf/{purchaseId}", method = RequestMethod.GET)
public ResponseEntity<ByteArrayResource> generateInventoryPurchasePdf(HttpServletResponse response,#PathVariable("purchaseId") Long purchaseId) throws Exception {
PurchaseOrder purchaseOrder = null;
purchaseOrder = purchaseService.findByPurchaseOrderId(purchaseId);
// generate the PDF
Map<Object,Object> pdfMap = new HashMap<>();
pdfMap.put("purchaseOrder", purchaseOrder);
pdfMap.put("purchaseOrderDetail", purchaseOrder.getPurchaseOrderDetail());
pdfMap.put("vendorName", purchaseOrder.getInvVendor().getName());
pdfMap.put("vendorAddrs", purchaseOrder.getInvVendor().getVenAddress().get(0));
File file = util.generatePdf("email/purchasepdf", pdfMap);
MediaType mediaType = MediaTypeUtils.getMediaTypeForFileName(this.servletContext, file.getName());
System.out.println("fileName: " + file.getName());
System.out.println("mediaType: " + mediaType);
//Path path = Paths.get(file.getAbsolutePath() + "/" + file.getName());
Path path = Paths.get(file.getAbsolutePath());
byte[] data = Files.readAllBytes(path);
ByteArrayResource resource = new ByteArrayResource(data);
return ResponseEntity.ok()
// Content-Disposition
.header(HttpHeaders.CONTENT_DISPOSITION, "attachment;filename=" + path.getFileName().toString())
// Content-Type
.contentType(mediaType) //
// Content-Lengh
.contentLength(data.length) //
.body(resource);
}
mediaUtil class:
public class MediaTypeUtils {
public static MediaType getMediaTypeForFileName(ServletContext servletContext, String fileName) {
// application/pdf
// application/xml
// image/gif, ...
String mineType = servletContext.getMimeType(fileName);
try {
MediaType mediaType = MediaType.parseMediaType(mineType);
return mediaType;
} catch (Exception e) {
return MediaType.APPLICATION_OCTET_STREAM;
}
}
}
PDF Generation code:
public File generatePdf(String templateName, Map<Object, Object> map) throws Exception {
Assert.notNull(templateName, "The templateName can not be null");
Context ctx = new Context();
if (map != null) {
Iterator<Entry<Object, Object>> itMap = map.entrySet().iterator();
while (itMap.hasNext()) {
Map.Entry<Object, Object> pair = itMap.next();
ctx.setVariable(pair.getKey().toString(), pair.getValue());
}
}
String processedHtml = templateEngine.process(templateName, ctx);
FileOutputStream os = null;
String fileName = "POLIST";
try {
final File outputFile = File.createTempFile(fileName, ".pdf",new File(servletContext.getRealPath("/")));
outputFile.mkdir();
os = new FileOutputStream(outputFile);
ITextRenderer renderer = new ITextRenderer();
renderer.setDocumentFromString(processedHtml);
renderer.layout();
renderer.createPDF(os, false);
renderer.finishPDF();
System.out.println("PDF created successfully");
return outputFile;
} finally {
if (os != null) {
try {
os.close();
} catch (IOException e) {
}
}
}
}
I'm not getting any error, PDF generate successfully in the server side. But In UI side not working.
Downloading files via AJAX isn't really a logical thing to do. When you make an AJAX call, the data returned from the server is returned into your page's JavaScript code (in the response callback value), rather than being returned to the browser itself to decide what to do. Therefore the browser has no way to initiate a download, because the browser is not directly in control of the response - your JavaScript code is in control instead.
As you've indicated in your comment below the question, there are workarounds you can use, but really the best approach is simply to use a regular non-AJAX request to download
For instance you could replace your jQuery code with something like
$(document).on('click', '.orderView', function(event){
orderId = $(this).attr('data');
window.open('../service/purchase/generateInventoryPurchasePdf/'+orderId);
});
This will download the document from a new tab without navigating away from the current page.
I have a C# app that implement a server ,I want this app to be able to get messages from the browser.
how can I send tcp messages using javascript that c# can read?
(obviously I can change the c# code and the javascript/angular code)
UPDATE - this is the c# code
private static TcpListener server;
static void Main(string[] args)
{
server = new TcpListener(IPAddress.Parse("127.0.0.1"), 476);
server.Start();
TcpClient client = server.AcceptTcpClient();
Console.WriteLine("accept spcket");
try
{
NetworkStream stream = client.GetStream();
//StreamReader read = new StreamReader(stream);
//Console.WriteLine(read.Read());
Byte[] b = new Byte[client.Available];
stream.Read(b, 0, b.Length);
string data = Encoding.UTF8.GetString(b);
Console.WriteLine(data);
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
and this is the javascript code
function send() {
let s = new WebSocket("ws://localhost:476");
alert("WebSocket is supported by your Browser!");
s.onopen = function () {
s.send("my data");
alert("sent");
}
how do I get the body of the messages in c#?
just create a header and message format like ipv4 and send it to the port.
I am building an android app. I have build a request using OKHTTP and I get the response as a string composed of html css and js content. This response is actualy a form that the user must use to allow the app to communicate with a given website.
Now I want the user to be able to see that response as an html page and clicks on a button to allow the communictaion. Only problem I don't know how to display that response as an html in webview or in the web browser.
From the MainActivity:
Authenticate myAouth = new Authenticate("myCostumerKey","mySecretKey");
try {
myResponse=myAouth.run("myUrlHere");
//System.out.println( myResponse);
} catch (Exception e) {
e.printStackTrace();
}
the Autheticate class
public class Authenticate {
private final OkHttpClient client;
String[] myResponse =new String[2];
public Authenticate( final String consumerKey, final String consumerSecret) {
client = new OkHttpClient.Builder()
.authenticator(new Authenticator() {
#Override public Request authenticate(Route route, Response response) throws IOException {
if (response.request().header("Authorization") != null) {
return null; // Give up, we've already attempted to authenticate.
}
System.out.println("Authenticating for response: " + response);
System.out.println("Challenges: " + response.challenges());
String credential = Credentials.basic(consumerKey, consumerSecret);
Request myRequest =response.request().newBuilder()
.header("Authorization", credential)
.build();
HttpUrl myURL = myRequest.url();
myResponse[0]= String.valueOf(myURL);
return myRequest;
}
})
.build();
}
#RequiresApi(api = Build.VERSION_CODES.KITKAT)
public String[] run(String url) throws Exception {
Request request = new Request.Builder()
.url(url)
.build();
try (Response response = client.newCall(request).execute()) {
if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);
myResponse[1]=response.body().string();
System.out.println(" URL is "+myResponse[0]+" my response body is "+myResponse[1]);
}
return myResponse;
}}
Any help would be apriciated.
Kind Regards
You can use the following code to convert the String to HTML and then display it in a WebView
try {
String html = new String(response, "UTF-8");
String mime = "text/html";
String encoding = "utf-8";
myWebView.getSettings().setJavaScriptEnabled(true);
myWebView.loadDataWithBaseURL(null, html, mime, encoding, null);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
Basically I'm just trying to create a simple HTML page that can send a string of text to the server. The server runs on some port on the localhost and receives that string.
I've found code for a simple server that can handle POST requests:
public static void main(String args[]) throws Exception
{
ServerSocket s = new ServerSocket(8080);
while (true) {
Socket remote = s.accept();
System.out.println("Connected");
BufferedReader in = new BufferedReader(new InputStreamReader(remote.getInputStream()));
PrintWriter out = new PrintWriter(remote.getOutputStream());
String str = ".";
while (!str.equals("")) {
str = in.readLine();
if (str.contains("GET")) {
break;
}
}
System.out.println(str);
out.println("HTTP/1.0 200 OK");
out.println("Content-Type: text/html");
out.println("Access-Control-Allow-Origin: null");
out.println("");
out.flush();
}
}
But I don't know what should I do further. I've learned that I need to use a XMLHttpRequest that can send asynchronous requests:
function sendData(data) {
var XHR = new XMLHttpRequest();
var urlEncodedData = "message";
var urlEncodedDataPairs = [];
var name;
for (name in data) {
urlEncodedDataPairs.push(encodeURIComponent(name) + '=' + encodeURIComponent(data[name]));
}
urlEncodedData = urlEncodedDataPairs.join('&').replace(/%20/g, '+');
XHR.open('POST', 'http://localhost:8080', true);
XHR.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
XHR.send(urlEncodedData);
}
So, I'm starting my server, opening the .html file with JS script, and the script connects to the server. How then can I handle the message that the script sends? How can I decode and print it? And, eventually, do I write the message sender in a right way?
If you're simply trying to hit the endpoint you created for testing & continuing to build, try using Postman. You should be able to write a custom body for your POST request.
I searched and tried a lot to develop an application which uses the content of a Website. I just saw the StackExchange app, which looks like I want to develop my application. The difference between web and application is here:
Browser:
App:
As you can see, there are some differences between the Browser and the App.
I hope somebody knows how to create an app like that, because after hours of searching I just found the solution of using a simple WebView (which is just a 1:1 like the browser) or to use Javascript in the app to remove some content (which is actually a bit buggy...).
To repeat: the point is, I want to get the content of a website (on start of the app) and to put it inside my application.
Cheers.
What you want to do is to scrape the websites in question by getting their html code and sorting it using some form of logic - I recomend xPath for this. then you can implement this data into some nice native interface.
You need however to be very aware that the data you get is not allways formated the way you want so all of your algorithems have to be very flexible.
the proccess can be cut into steps like this
retrive data from website (DefaultHttpClient and AsyncTask)
analyse and retrive relevant data (your relevant algorithm)
show data to user (Your interface implementation)
UPDATE
Bellow is some example code to fetch some data of a website it implements html-cleaner libary and you will need to implement this in your project.
class GetStationsClass extends AsyncTask<String, String, String> {
#Override
protected String doInBackground(String... params) {
HttpClient httpclient = new DefaultHttpClient();
httpclient.getParams().setParameter(CoreProtocolPNames.PROTOCOL_VERSION, HttpVersion.HTTP_1_1);
httpclient.getParams().setParameter(CoreProtocolPNames.HTTP_ELEMENT_CHARSET, "iso-8859-1");
HttpPost httppost = new HttpPost("http://ntlive.dk/rt/route?id=786");
httppost.setHeader("Accept-Charset", "iso-8859-1, unicode-1-1;q=0.8");
try {
// Add your data
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(3);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs, "utf-8"));
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
int status = response.getStatusLine().getStatusCode();
String data = "";
if (status != HttpStatus.SC_OK) {
ByteArrayOutputStream ostream = new ByteArrayOutputStream();
response.getEntity().writeTo(ostream);
data = ostream.toString();
} else {
BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(),
"iso-8859-1"));
String line = null;
while ((line = reader.readLine()) != null) {
data += line;
}
XPath xpath = XPathFactory.newInstance().newXPath();
try {
Document document = readDocument(data);
NodeList nodes = (NodeList) xpath.evaluate("//*[#id=\"container\"]/ul/li", document,
XPathConstants.NODESET);
for (int i = 0; i < nodes.getLength(); i++) {
Node thisNode = nodes.item(i);
Log.v("",thisNode.getTextContent().trim);
}
} catch (XPathExpressionException e) {
e.printStackTrace();
}
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
//update user interface here
}
}
private Document readDocument(String content) {
Long timeStart = new Date().getTime();
TagNode tagNode = new HtmlCleaner().clean(content);
Document doc = null;
try {
doc = new DomSerializer(new CleanerProperties()).createDOM(tagNode);
return doc;
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
return doc;
}
to run the code above use
new getStationsClass.execute();