I'm trying to read a file from
public static void printLines(String doc){
Scanner input = null;
input = new Scanner(doc + ".txt"));
while(input.hasNext()){
String nextLine = input.nextLine();
System.out.println(nextLine);
}
input.close;
}
The code above is from a method that takes in String doc as a parameter, and prints out every line. In my main, I used a try catch block to catch a FileNotFoundException. However, when I try running the program, it hits FileNotFoundException all the time.
I'm using Eclipse and the text file and java file are both in the same "Java Project". Is there any reason why my method can't read the text file? Please help!
Try to print the doc inside it. It may be including the extension of the file too.
For example, if the doc is /home/user/Desktop/mySample.txt the Scanner will try to find /home/user/Desktop/mySample.txt.txt which is not available, because you are concatenating the extension .txt again.
The reason you're getting FileNotFoundException is that you're using the wrong constuctor of Scanner.
Change input = new Scanner(doc + ".txt")); to
input = new Scanner(new File(doc + ".txt"))); should suit your need.
Related
So, using PyQt5's QWebEngineView and the .setHTML and .setContent methods have a 2 MB size limitation. When googling for solutions around this, I found two methods:
Use SimpleHTTPServer to serve the file. This however gets nuked by a firewall employed in the company.
Use File Urls and point to local files. This however is a rather bad solution, as the HTML contains confidential data and I can't leave it on the harddrive, under any circumstance.
The best solution I currently see is to use file urls, and get rid of the file on program exit/when loadCompleted reports it is done, whichever comes first.
This is however not a great solution and I wanted to ask if there is a solution I'm overlooking that would be better?
Why don't you load/link most of the content through a custom url scheme handler?
webEngineView->page()->profile()->installUrlSchemeHandler("app", new UrlSchemeHandler(e));
class UrlSchemeHandler : public QWebEngineUrlSchemeHandler
{ Q_OBJECT
public:
void requestStarted(QWebEngineUrlRequestJob *request) {
QUrl url = request->requestUrl();
QString filePath = url.path().mid(1);
// get the data for this url
QByteArray data = ..
//
if (!data.isEmpty())
{
QMimeDatabase db;
QString contentType = db.mimeTypeForFileNameAndData(filePath,data).name();
QBuffer *buffer = new QBuffer();
buffer->open(QIODevice::WriteOnly);
buffer->write(data);
buffer->close();
connect(request, SIGNAL(destroyed()), buffer, SLOT(deleteLater()));
request->reply(contentType.toUtf8(), buffer);
} else {
request->fail(QWebEngineUrlRequestJob::UrlNotFound);
}
}
};
you can then load a website by webEngineView->load(new QUrl("app://start.html"));
All relative pathes from inside will also be forwarded to your UrlSchemeHandler..
And rember to add the respective includes
#include <QWebEngineUrlRequestJob>
#include <QWebEngineUrlSchemeHandler>
#include <QBuffer>
One way you can go around this is to use requests and QWebEnginePage's method runJavaScript:
web_engine = QWebEngineView()
web_page = web_engine.page()
web_page.setHtml('')
url = 'https://youtube.com'
page_content = requests.get(url).text
# document.write writes a string of text to a document stream
# https://developer.mozilla.org/en-US/docs/Web/API/Document/write
# And backtick symbol(``) is for multiline strings
web_page.runJavaScript('document.write(`{}`);'.format(page_content))
i have a question. If there is a possibility at windows phone 8 at visual studio to create button event to read text file? i know about streamReader and if i declare wchich exacly file i want to read, but if i want to choose from list of files wchich i want to display. i did research on the Internet but i didint find an answer. I know i can use isolatedStorage to read music, video, image but not text files, on the app i created few files with text in it and i want users to have posibility to display one from this file, whichever they want to see. So, can you tell me how to do this?
You can use IsolatedStorage to read any file type you wish. You must of been using something like a Launcher that filters out the file type based on the Chooser.
You can open a file like this:
private async Task<string> ReadTextFile(string file_name)
{
// return buffer
string file_content = "";
// Get the local folder
StorageFolder local = Windows.Storage.ApplicationData.Current.LocalFolder;
if (local != null)
{
// Get the file
StorageFile file;
try
{
file = await local.GetFileAsync(file_name);
}
catch (Exception ex)
{
// no file, return empty
return file_content;
}
// Get the stream
System.IO.Stream file_stream = await file.OpenStreamForReadAsync();
// Read the data
using (StreamReader streamReader = new StreamReader(file_stream))
{
file_content = streamReader.ReadToEnd(); // read the full text file
streamReader.Close();
}
// Close the stream
file_stream.Close();
}
// return
return file_content;
}
If you want to get the PackageLocation (files that you added into the project like assets and images) then replace the LocalFolder with
Windows.ApplicationModel.Package package = Windows.ApplicationModel.Package.Current;
Windows.Storage.StorageFolder installedLocation = package.InstalledLocation;
With Windows Phone 8.1, File Pickers are allowed, consisting the same functionality you are expecting, so probably you might want to upgrade your app to WP8.1.
Here's more info on this API : Working with File Pickers
I have a bunch (over 1000) HTML files with just simple text. It's just a combination of text within a <table>. It's an internal batch of documents, not for web production.
The job we have is to convert them into JPEG files using Photoshop and the old copy paste method. It's tedious.
Is there a way you would do this process to make it more efficient/easier/simple?
I thought about trying to convert the HTML into Excel and then mail merging it into Word to print as JGEG. But I can't find (and rightly so) anything to convert HTML to XLSX.
Thoughts? Or is this just a manual job?
Here's a little something I created to convert a single html file to jpeg. It's not pretty (to say the least), but it works fine with a table larger than my screen. Put it inside a windows forms project. You can add more checks and call this program in a loop, or refactor it to work on multiple html files.
Ideas and techniques taken from -
Finding the needed size - http://social.msdn.microsoft.com/Forums/ie/en-US/f6f0c641-43bd-44cc-8be0-12b40fbc4c43/webbrowser-object-use-to-find-the-width-of-a-web-page
Creating the graphics - http://cplus.about.com/od/learnc/a/How-To-Save-Web-Page-Screen-Grab-csharp.htm
A table for example - copy-paste enlarged version of http://www.w3schools.com/html/html_tables.asp
static class Program
{
static WebBrowser webBrowser = new WebBrowser();
private static string m_fileName;
[STAThread]
static void Main(string[] args)
{
if (args.Length != 1)
{
MessageBox.Show("Usage: [fileName]");
return;
}
m_fileName = args[0];
webBrowser.DocumentCompleted += (a, b) => webBrowser_DocumentCompleted();
webBrowser.ScrollBarsEnabled = false; // Don't want them rendered
webBrowser.Navigate(new Uri(m_fileName));
Application.Run();
}
static void webBrowser_DocumentCompleted()
{
// Get the needed size of the control
webBrowser.Width = webBrowser.Document.Body.ScrollRectangle.Width + webBrowser.Margin.Horizontal;
webBrowser.Height = webBrowser.Document.Body.ScrollRectangle.Height + webBrowser.Margin.Vertical;
// Create the graphics and save the image
using (var graphics = webBrowser.CreateGraphics())
{
var bitmap = new Bitmap(webBrowser.Size.Width, webBrowser.Size.Height, graphics);
webBrowser.DrawToBitmap(bitmap, webBrowser.ClientRectangle);
string newFileName = Path.ChangeExtension(m_fileName, ".jpg");
bitmap.Save(newFileName, ImageFormat.Jpeg);
}
// Shamefully exit the application
Application.ExitThread();
}
}
You can load all files in one page and use this lib html2canvas to covert.
You can running in the background use nodejs with node-canvas or make it a desk app with node-webkit
In case anyone was looking for answer that works, I ended up using a program called Prince: https://www.princexml.com
It works amazingly, and just have to target the HTML with CSS or JS to make it match your output!
In my program I have a string which contains URLs separated by /n (One per line)
Let's say the string is called "links". I want to take this string and generate a HTML file that will automatically open in my default browser which will make each URL a hyperlink (one per line). How would I make such a report not using any third party components using WPF C# 4.0? I want the report to be generated by clicking a button called "Export".
There are plenty of ways to do this, but here is a quick and dirty example (debugging may be necessary since I wrote this on the fly). [Edit: Now uses Uri objects to formulate the actual address.]
private void export_Click(object sender, RoutedEventArgs e)
{
string tempFileName = "list.html";
string links = "http://www.google.com/#sclient=psy&hl=en&site=&source=hp&q=test+me&aq=f&aqi=&aql=&oq=&gs_rfai=&pbx=1&fp=ddfbf15c2e2f4021\nhttp://www.testme.com/Test-Prep.html?afdt=Q3RzePF0jU8KEwja-5WM7PqkAhUUiZ0KHaoG_wcYASAAMJbwoAM4MEC4w6uX7dS53gdQlvCgA1CEra8PUJzr_xNQg73wFVCKttweUJStzNoBUNv67ZsD";
List<Uri> uriCollection = new List<Uri>();
foreach (string url in links.Split(new char[] { '\n' }, StringSplitOptions.RemoveEmptyEntries))
{
uriCollection.Add(new Uri(url));
}
// Create temporary file.
using (TextWriter writer = new StreamWriter(tempFileName))
{
try
{
writer.WriteLine("<html>");
writer.WriteLine("<head><title>Links</title></head>");
writer.WriteLine("<body>");
writer.WriteLine("<p>");
foreach (Uri uri in uriCollection)
{
writer.WriteLine("{1}<br />", uri.OriginalString, uri.Host);
}
writer.WriteLine("</p>");
writer.WriteLine("</body>");
writer.WriteLine("</html>");
}
catch (Exception ex)
{
System.Diagnostics.Trace.TraceError(ex.Message);
}
finally
{
writer.Close();
}
}
// Open browser with temporary file.
if (File.Exists(tempFileName))
{
System.Diagnostics.Process.Start(tempFileName);
}
}
The 'Export' button is wired to the event 'export_Click'. I hard-coded the the string with '\n''s for the example. Simply break these apart using split and write a temporary file creating the HTML you need. Then, once the file is completed, you can open it using the Process.Start() method.
Ideally this can be done using DataBinding and other elements available in WPF if the need to open a browser window was not required. This would also remove any external dependencies the program may have.
I'm attempting to create a PDF file from an HTML file. After looking around a little I've found: wkhtmltopdf to be perfect. I need to call this .exe from the ASP.NET server. I've attempted:
Process p = new Process();
p.StartInfo.UseShellExecute = false;
p.StartInfo.FileName = HttpContext.Current.Server.MapPath("wkhtmltopdf.exe");
p.StartInfo.Arguments = "TestPDF.htm TestPDF.pdf";
p.Start();
p.WaitForExit();
With no success of any files being created on the server. Can anyone give me a pointer in the right direction? I put the wkhtmltopdf.exe file at the top level directory of the site. Is there anywhere else it should be held?
Edit: If anyone has better solutions to dynamically create pdf files from html, please let me know.
Update:
My answer below, creates the pdf file on the disk. I then streamed that file to the users browser as a download. Consider using something like Hath's answer below to get wkhtml2pdf to output to a stream instead and then send that directly to the user - that will bypass lots of issues with file permissions etc.
My original answer:
Make sure you've specified an output path for the PDF that is writeable by the ASP.NET process of IIS running on your server (usually NETWORK_SERVICE I think).
Mine looks like this (and it works):
/// <summary>
/// Convert Html page at a given URL to a PDF file using open-source tool wkhtml2pdf
/// </summary>
/// <param name="Url"></param>
/// <param name="outputFilename"></param>
/// <returns></returns>
public static bool HtmlToPdf(string Url, string outputFilename)
{
// assemble destination PDF file name
string filename = ConfigurationManager.AppSettings["ExportFilePath"] + "\\" + outputFilename + ".pdf";
// get proj no for header
Project project = new Project(int.Parse(outputFilename));
var p = new System.Diagnostics.Process();
p.StartInfo.FileName = ConfigurationManager.AppSettings["HtmlToPdfExePath"];
string switches = "--print-media-type ";
switches += "--margin-top 4mm --margin-bottom 4mm --margin-right 0mm --margin-left 0mm ";
switches += "--page-size A4 ";
switches += "--no-background ";
switches += "--redirect-delay 100";
p.StartInfo.Arguments = switches + " " + Url + " " + filename;
p.StartInfo.UseShellExecute = false; // needs to be false in order to redirect output
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.RedirectStandardError = true;
p.StartInfo.RedirectStandardInput = true; // redirect all 3, as it should be all 3 or none
p.StartInfo.WorkingDirectory = StripFilenameFromFullPath(p.StartInfo.FileName);
p.Start();
// read the output here...
string output = p.StandardOutput.ReadToEnd();
// ...then wait n milliseconds for exit (as after exit, it can't read the output)
p.WaitForExit(60000);
// read the exit code, close process
int returnCode = p.ExitCode;
p.Close();
// if 0 or 2, it worked (not sure about other values, I want a better way to confirm this)
return (returnCode == 0 || returnCode == 2);
}
I had the same problem when i tried using msmq with a windows service but it was very slow for some reason. (the process part).
This is what finally worked:
private void DoDownload()
{
var url = Request.Url.GetLeftPart(UriPartial.Authority) + "/CPCDownload.aspx?IsPDF=False?UserID=" + this.CurrentUser.UserID.ToString();
var file = WKHtmlToPdf(url);
if (file != null)
{
Response.ContentType = "Application/pdf";
Response.BinaryWrite(file);
Response.End();
}
}
public byte[] WKHtmlToPdf(string url)
{
var fileName = " - ";
var wkhtmlDir = "C:\\Program Files\\wkhtmltopdf\\";
var wkhtml = "C:\\Program Files\\wkhtmltopdf\\wkhtmltopdf.exe";
var p = new Process();
p.StartInfo.CreateNoWindow = true;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.RedirectStandardError = true;
p.StartInfo.RedirectStandardInput = true;
p.StartInfo.UseShellExecute = false;
p.StartInfo.FileName = wkhtml;
p.StartInfo.WorkingDirectory = wkhtmlDir;
string switches = "";
switches += "--print-media-type ";
switches += "--margin-top 10mm --margin-bottom 10mm --margin-right 10mm --margin-left 10mm ";
switches += "--page-size Letter ";
p.StartInfo.Arguments = switches + " " + url + " " + fileName;
p.Start();
//read output
byte[] buffer = new byte[32768];
byte[] file;
using(var ms = new MemoryStream())
{
while(true)
{
int read = p.StandardOutput.BaseStream.Read(buffer, 0,buffer.Length);
if(read <=0)
{
break;
}
ms.Write(buffer, 0, read);
}
file = ms.ToArray();
}
// wait or exit
p.WaitForExit(60000);
// read the exit code, close process
int returnCode = p.ExitCode;
p.Close();
return returnCode == 0 ? file : null;
}
Thanks Graham Ambrose and everyone else.
OK, so this is an old question, but an excellent one. And since I did not find a good answer, I made my own :) Also, I've posted this super simple project to GitHub.
Here is some sample code:
var pdfData = HtmlToXConverter.ConvertToPdf("<h1>SOO COOL!</h1>");
Here are some key points:
No P/Invoke
No creating of a new process
No file-system (all in RAM)
Native .NET DLL with intellisense, etc.
Ability to generate a PDF or PNG (HtmlToXConverter.ConvertToPng)
Check out the C# wrapper library (using P/Invoke) for the wkhtmltopdf library: https://github.com/pruiz/WkHtmlToXSharp
There are many reason why this is generally a bad idea. How are you going to control the executables that get spawned off but end up living on in memory if there is a crash? What about denial-of-service attacks, or if something malicious gets into TestPDF.htm?
My understanding is that the ASP.NET user account will not have the rights to logon locally. It also needs to have the correct file permissions to access the executable and to write to the file system. You need to edit the local security policy and let the ASP.NET user account (maybe ASPNET) logon locally (it may be in the deny list by default). Then you need to edit the permissions on the NTFS filesystem for the other files. If you are in a shared hosting environment it may be impossible to apply the configuration you need.
The best way to use an external executable like this is to queue jobs from the ASP.NET code and have some sort of service monitor the queue. If you do this you will protect yourself from all sorts of bad things happening. The maintenance issues with changing the user account are not worth the effort in my opinion, and whilst setting up a service or scheduled job is a pain, its just a better design. The ASP.NET page should poll a result queue for the output and you can present the user with a wait page. This is acceptable in most cases.
You can tell wkhtmltopdf to send it's output to sout by specifying "-" as the output file.
You can then read the output from the process into the response stream and avoid the permissions issues with writing to the file system.
My take on this with 2018 stuff.
I am using async. I am streaming to and from wkhtmltopdf. I created a new StreamWriter because wkhtmltopdf is expecting utf-8 by default but it is set to something else when the process starts.
I didn't include a lot of arguments since those varies from user to user. You can add what you need using additionalArgs.
I removed p.WaitForExit(...) since I wasn't handling if it fails and it would hang anyway on await tStandardOutput. If timeout is needed, then you would have to call Wait(...) on the different tasks with a cancellationtoken or timeout and handle accordingly.
public async Task<byte[]> GeneratePdf(string html, string additionalArgs)
{
ProcessStartInfo psi = new ProcessStartInfo
{
FileName = #"C:\Program Files\wkhtmltopdf\wkhtmltopdf.exe",
UseShellExecute = false,
CreateNoWindow = true,
RedirectStandardInput = true,
RedirectStandardOutput = true,
RedirectStandardError = true,
Arguments = "-q -n " + additionalArgs + " - -";
};
using (var p = Process.Start(psi))
using (var pdfSream = new MemoryStream())
using (var utf8Writer = new StreamWriter(p.StandardInput.BaseStream,
Encoding.UTF8))
{
await utf8Writer.WriteAsync(html);
utf8Writer.Close();
var tStdOut = p.StandardOutput.BaseStream.CopyToAsync(pdfSream);
var tStdError = p.StandardError.ReadToEndAsync();
await tStandardOutput;
string errors = await tStandardError;
if (!string.IsNullOrEmpty(errors)) { /* deal/log with errors */ }
return pdfSream.ToArray();
}
}
Things I haven't included in there but could be useful if you have images, css or other stuff that wkhtmltopdf will have to load when rendering the html page:
you can pass the authentication cookie using --cookie
in the header of the html page, you can set the base tag with href pointing to the server and wkhtmltopdf will use that if need be
Thanks for the question / answer / all the comments above. I came upon this when I was writing my own C# wrapper for WKHTMLtoPDF and it answered a couple of the problems I had. I ended up writing about this in a blog post - which also contains my wrapper (you'll no doubt see the "inspiration" from the entries above seeping into my code...)
Making PDFs from HTML in C# using WKHTMLtoPDF
Thanks again guys!
The ASP .Net process probably doesn't have write access to the directory.
Try telling it to write to %TEMP%, and see if it works.
Also, make your ASP .Net page echo the process's stdout and stderr, and check for error messages.
Generally return code =0 is coming if the pdf file is created properly and correctly.If it's not created then the value is in -ve range.
using System;
using System.Diagnostics;
using System.Web;
public partial class pdftest : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
private void fn_test()
{
try
{
string url = HttpContext.Current.Request.Url.AbsoluteUri;
Response.Write(url);
ProcessStartInfo startInfo = new ProcessStartInfo();
startInfo.FileName =
#"C:\PROGRA~1\WKHTML~1\wkhtmltopdf.exe";//"wkhtmltopdf.exe";
startInfo.Arguments = url + #" C:\test"
+ Guid.NewGuid().ToString() + ".pdf";
Process.Start(startInfo);
}
catch (Exception ex)
{
string xx = ex.Message.ToString();
Response.Write("<br>" + xx);
}
}
protected void btn_test_Click(object sender, EventArgs e)
{
fn_test();
}
}