Develop Reference

Android Capacitor JS Plugin does not reply

I am working on a java plugin that is supposed to recieve some info from a js vue3 program and then do a URL post operation, and then return some of the info found back to the js code. I am using capacitor and android. This is my error message:
2022-08-22 13:46:23.773 27544-27544/org.theguy.GptEtc E/Capacitor/Console: File: http://localhost/js/app.6577adf2.js - Line 1 - Msg: Uncaught (in promise) SyntaxError: Unexpected token o in JSON at position 1
I think this means that something other than valid JSON is being delivered to the js code. I know that the app is delivering info to the java android class. This is some of my java code.
#CapacitorPlugin(name = "URLPOST")
public class PluginURLPost extends Plugin {
#PluginMethod()
public void post(PluginCall call) {
String post_url = call.getString("post_url", "");
String bearer = call.getString("bearer", "pipeline_");
JSObject ret = new JSObject();
try {
String value = this.doPost(post_url, bearer);
System.out.println("value " + value);
Gson gson = new Gson();
JsonReader reader = new JsonReader(new StringReader(value));
ResultPreview preview = gson.fromJson(reader, ResultPreview.class);
String val = preview.getResult_preview()[0][0];
val = "result string here."; // <-- add this for easy testing
ret.put("response_text", val.replace("\n", "\\n"));
System.out.println("response here: " + val);
}
catch (Exception e) {
e.printStackTrace();
}
//call.setKeepAlive(true);
call.resolve(ret);
}
OkHttpClient client = new OkHttpClient();
public static final MediaType JSON
= MediaType.parse("application/json; charset=utf-8");
String doPost(String post_url, String bearer ) throws IOException {
// ... do some post request here ...
return response_body;
}
}
class ResultPreview {
#SerializedName("result_preview")
String [][] result_preview ;
public void setResult_preview(String[][] result) {
this.result_preview = result;
}
public String[][] getResult_preview() {
return this.result_preview;
}
}
This is some of my js code.
import { registerPlugin } from "#capacitor/core";
const URLPOST = registerPlugin("URLPOST");
const request = {
"line": line,
"pipeline_model": details[engine]["app_model"].trim(),
"bearer": details[engine]["api_key"].trim(),
"post_url": details[engine]["url"].trim(),
"length": 25,
"top_k": 50
};
console.log("request", request);
var {response_text} = await URLPOST.post(request);
console.log("response_text 1",response_text);
I don't know what to do.

I tried this, and things work better. I don't know if this is the ultimate solution.
#PluginMethod()
public void post(PluginCall call) {
bridge.saveCall(call); // <-- add this
call.release(bridge); // <-- add this
String pipeline_model = call.getString("pipeline_model", "pipeline_");
String post_url = call.getString("post_url", "");
JSObject ret = new JSObject();
try {
String value = this.doPost(post_url);
Gson gson = new Gson();
JsonReader reader = new JsonReader(new StringReader(value));
ResultPreview preview = gson.fromJson(reader, ResultPreview.class);
String val = preview.getResult_preview()[0][0];
ret.put("response_text", val.replace("\n", "\\n"));
System.out.println("response here: " + val);
}
catch (Exception e) {
e.printStackTrace();
}
call.resolve(ret);
}
This is not found on the capacitor site, but instead I found it digging around the internet.

Tableau Integration with Web project

I am doing Tableau integration with web project using java script api. I have configured my ip in tableau server using commnad :tabadmin set wgserver.trusted_hosts "" and respective commands .But I am not able to get the ticket, ended up with -1. I have followed all configuration steps.
public class TableauServlet extends javax.servlet.http.HttpServlet {
private static final long serialVersionUID = 1L;
public TableauServlet() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
final String user = "raghu";
final String wgserver = "103.xxx.xxx.xx";
final String dst = "views/Regional/College?:iid=1";
final String params = ":embed=yes&:toolbar=yes";
String ticket = getTrustedTicket(wgserver, user, request.getRemoteAddr());
if ( !ticket.equals("-1") ) {
response.setStatus(HttpServletResponse.SC_MOVED_TEMPORARILY);
response.setHeader("Location", "http://" + wgserver + "/trusted/" + ticket + "/" + dst + "?" + params);
}
else
// handle error
throw new ServletException("Invalid ticket " + ticket);
}
// the client_ip parameter isn't necessary to send in the POST unless you have
// wgserver.extended_trusted_ip_checking enabled (it's disabled by default)
private String getTrustedTicket(String wgserver, String user, String remoteAddr)
throws ServletException
{
OutputStreamWriter out = null;
BufferedReader in = null;
try {
// Encode the parameters
StringBuffer data = new StringBuffer();
data.append(URLEncoder.encode("username", "UTF-8"));
data.append("=");
data.append(URLEncoder.encode(user, "UTF-8"));
data.append("&");
data.append(URLEncoder.encode("client_ip", "UTF-8"));
data.append("=");
data.append(URLEncoder.encode(remoteAddr, "UTF-8"));
// Send the request
URL url = new URL("http://" + wgserver + "/trusted");
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
out = new OutputStreamWriter(conn.getOutputStream());
out.write(data.toString());
out.flush();
// Read the response
StringBuffer rsp = new StringBuffer();
in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line;
while ( (line = in.readLine()) != null) {
rsp.append(line);
}
return rsp.toString();
} catch (Exception e) {
throw new ServletException(e);
}
finally {
try {
if (in != null) in.close();
if (out != null) out.close();
}
catch (IOException e) {}
}
}
}

I think you are missing 'target_site' parameter in your URL where you get trusted ticket, its needed if you don't have the 'views/Regional/College' in your default site.
I had gone through a lot of frustration with the '-1' ticket too!
One thing you might try is restarting the tableau server after you have added your web server IP to the trusted_hosts of tableau.
Another thing we ended up doing was adding both the internal ip and external ip of the web server to trusted_hosts on tableau. Since you are using 103.xxx.xxx.xx as your tableau server I am assuming both servers live on the same internal network. You might try that if everything else fails.
My code is almost exactly same as yours and works fine. So if your problem persists, it must be something related to configuration.
here is my code:
private String getAuthenticationTicket(String tableauServerUserName,String tableauServerUrl, String targetSite) {
OutputStreamWriter out = null;
BufferedReader in = null;
try {
StringBuffer data = new StringBuffer();
data.append(URLEncoder.encode("username", Constant.UTF_8));
data.append("=");
data.append(URLEncoder.encode(tableauServerUserName, Constant.UTF_8));
data.append("&");
data.append(URLEncoder.encode("target_site", Constant.UTF_8));
data.append("=");
data.append(URLEncoder.encode(targetSite, Constant.UTF_8));
URL url = new URL(tableauServerUrl + "/" + "trusted");
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
out = new OutputStreamWriter(conn.getOutputStream());
out.write(data.toString());
out.flush();
StringBuffer rsp = new StringBuffer();
in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
String line;
while ((line = in.readLine()) != null) {
rsp.append(line);
}
return rsp.toString();
} catch (Exception ex) {
//log stuff, handle error
return null;
} finally {
try {
if (in != null)
in.close();
if (out != null)
out.close();
} catch (IOException ex) {
//log stuff, handle error
}
}
}

Delete folder before HttpResponseMessage return

I want to delete a folder and its content before returning some data from the browser.
I am using ASP .NET MVC 5 and just javascript with some DevExpress components.
The method should return a HttpResponseMessage, which is the excel file. The file is created in a temp folder and after that I want to delete it.
I get always an "UnauthorizedAccessException" exception.
Any idea how the logic flow should be to return the file and delete it?
I was thinking on calling a new method after finishing the ExportExcelChart but maybe there is a better way to achieve the expected result.
How
JS (browser)
function SaveChart(s, e) {
//debugger;
if (e.item.name === 'mnuSaveToDisk') {
averageChart.printOptions.landscape = true;
averageChart.printOptions.SetSizeMode('Stretch');
averageChart.SaveToDisk('pdf', "average curves");
} else if (e.item.name == 'mnExportChart') {
ChartLoadingPanel.Show();
#*$.get('#Url.Action("ExportExcelChart", "Mindboard")', {}, null);*#
window.location = '#Url.Action("ExportExcelChart", "Mindboard")';
ChartLoadingPanel.Hide();
}
}
Controller
public HttpResponseMessage ExportExcelChart()
{
try
{
// create excel file
String tmpRandomFolderName = DataService.RandomString(20);
string tmpFolderPath = Path.Combine(Server.MapPath("~/App_Data"), "TEMP", tmpRandomFolderName);
string tmpOriginFile = Server.MapPath("~/App_Data") + "/ExportChartAverage.xlsx";
string tmpNewFile = tmpFolderPath + "/ExportChartAverage.xlsx";
if (!Directory.Exists(tmpFolderPath))
Directory.CreateDirectory(tmpFolderPath);
System.IO.File.Copy(tmpOriginFile, tmpNewFile);
// open excel file
FileInfo tmpExcelFile = new FileInfo(tmpNewFile);
ExcelPackage pck = new ExcelPackage(tmpExcelFile);
var ws = pck.Workbook.Worksheets[1];
// do stuff...
pck.SaveAs(Response.OutputStream);
Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
Response.AddHeader("content-disposition", "attachment; filename=ExportChartAverage.xlsx");
if (Directory.Exists(tmpFolderPath))
{
if (System.IO.File.Exists(tmpNewFile))
System.IO.File.Delete(tmpNewFile);
Directory.Delete(tmpFolderPath, true);
}
var response = new HttpResponseMessage(HttpStatusCode.OK);
return response;
}
catch (IOException ex)
{
var response = new HttpResponseMessage(HttpStatusCode.NotFound);
response.Content = new StringContent(ex.Message);
return response;
//throw ex;
}
catch (UnauthorizedAccessException ex)
{
var response = new HttpResponseMessage(HttpStatusCode.NotFound);
response.Content = new StringContent(ex.Message);
return response;
//throw ex;
}
catch (Exception)
{
throw;
}
}

loading an image file hosted in assets folder exposed with web server in the app

In my app, I have created web server which is hosting a web app. All the files of web app are placed in assets folder.
Now, i start the web server by running my application and then from crome brower, I try to run my web app by calling index.html file. The html, css part of the page is getting loaded properly but the images are not getting loaded in the page:
Here is my HttpRequestHandlerCode:
public class HomePageHandler implements HttpRequestHandler {
private Context context = null;
private static final Map<String, String> mimeTypes = new HashMap<String, String>() {
{
put("css", "text/css");
put("htm", "text/html");
put("html", "text/html");
put("xhtml", "text/xhtml");
put("xml", "text/xml");
put("java", "text/x-java-source, text/java");
put("md", "text/plain");
put("txt", "text/plain");
put("asc", "text/plain");
put("gif", "image/gif");
put("jpg", "image/jpeg");
put("jpeg", "image/jpeg");
put("png", "image/png");
put("svg", "image/svg+xml");
put("mp3", "audio/mpeg");
put("m3u", "audio/mpeg-url");
put("mp4", "video/mp4");
put("ogv", "video/ogg");
put("flv", "video/x-flv");
put("mov", "video/quicktime");
put("swf", "application/x-shockwave-flash");
put("js", "application/javascript");
put("pdf", "application/pdf");
put("doc", "application/msword");
put("ogg", "application/x-ogg");
put("zip", "application/octet-stream");
put("exe", "application/octet-stream");
put("class", "application/octet-stream");
put("m3u8", "application/vnd.apple.mpegurl");
put("ts", " video/mp2t");
}
};
public HomePageHandler(Context context){
this.context = context;
}
#Override
public void handle(HttpRequest request, HttpResponse response, HttpContext httpContext) throws HttpException, IOException {
//String contentType = "text/html";
//Log.i("Sushill", "..request : " + request.getRequestLine().getUri().toString());
final String requestUri = request.getRequestLine().getUri().toString();
final String contentType = contentType(requestUri);
String resp = Utility.openHTMLStringFromAssets(context, "html" + requestUri);
writer.write(resp);
writer.flush();
// }
}
});
((EntityTemplate) entity).setContentType(contentType);
response.setEntity(entity);
}
}
/**
* Get content type
*
* #param fileName
* The file
* #return Content type
*/
private String contentType(String fileName) {
String ext = "";
int idx = fileName.lastIndexOf(".");
if (idx >= 0) {
ext = fileName.substring(idx + 1);
}
if (mimeTypes.containsKey(ext)) {
//Log.i("Sushill", "...ext : " + ext);
return mimeTypes.get(ext);
}
else
return "application/octet-stream";
}
To handle image, I tried this but it did not work :
if(contentType.contains("image")) {
InputStream is = Utility.openImageFromAssets(context, "html" + requestUri);
char[] buffer = new char[1024];
try {
Reader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
int n;
while ((n = reader.read(buffer)) != -1) {
writer.write(buffer, 0, n);
}
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
Can someone please help me in figuring out how to load the images also in my browser.
Thanks for any help

Do away with BufferedReader(new InputStreamReader' so you do away with UTF-8 too. Use only InputStream 'is'. Do away with writer. You are not showing what 'writer' is but do away with it. Use the OutputStream of the http connection. Keep the buffer and the loop where you read in the buffer and write from the buffer.

Error on Downloading From using Asp.net web api

I'm using the code below for downloading with the web API in ASP.NET.
When I'm trying to click the download button, it calls the API.
After executing the "DownloadFile"-function, the download dialog box isn't coming .
[HttpGet]
public HttpResponseMessage DownloadFile(string DownloadFilePath)
{
HttpResponseMessage result = null;
var localFilePath = HttpContext.Current.Server.MapPath(DownloadFilePath);
// check if parameter is valid
if (String.IsNullOrEmpty(DownloadFilePath))
{
result = Request.CreateResponse(HttpStatusCode.BadRequest);
}
// check if file exists on the server
else if (!File.Exists(localFilePath))
{
result = Request.CreateResponse(HttpStatusCode.Gone);
}
else
{// serve the file to the client
result = Request.CreateResponse(HttpStatusCode.OK);
result.Content = new StreamContent(new FileStream(localFilePath, FileMode.Open, FileAccess.Read));
result.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment");
result.Content.Headers.ContentDisposition.FileName = DownloadFilePath;
}
return result;
}
I didn't get any exception from the code above, but the dialog box for downloading the file isn't coming.

Here is the code, I am using and it works great. I hope it will give you an idea
....
var fileBytes = Helper.GetFileBytes(filePath);//convert file to bytes
var stream = new MemoryStream(fileBytes);
resp.Content = new StreamContent(stream);
resp.Content.Headers.ContentType = new MediaTypeHeaderValue("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
resp.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment") { FileName = filerequest.FileName };
resp.Content.Headers.Add("Content-Encoding", "UTF-8");
return resp;
And, here is the code for GetFileBytes method,
public static byte[] GetFileBytes(string filePath)
{
var fileInfo = new FileInfo(filePath);
if (fileInfo.Exists)
{
return File.ReadAllBytes(fileInfo.FullName);
}
return null;
}