I have a JWS application that caches several different resource types. However, I do not want to cache .svg images. It seems that the framework does not honor the server side cache control HTTP headers that I have set.
I was wondering if there is some other way that I could load .svg images without caching. I am open to putting a solution in my loadSVGDocument() method, but my code is currently built around Apache Batik for loading .svg files. Is there a solution to pass an InputStream with a noCache flag within the Batik library similar to what DocumentBuilderFactory provides below?
URL url = new URL(fileLocation);
URLConnection connection = url.openConnection();
// Prevent JavaWebStart from returning cached copy.
connection.setUseCaches(false);
// Now fetch the content, e.g.
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
Document doc = db.parse(connection.getInputStream());
Here is my current loadSVGDocument() method that uses several Apache Batik fields:
public void loadSVGDocument(final String url)
{
System.out.println("THE SVG URL: " + url);
String oldURI = null;
if (svgDocument != null)
{
oldURI = svgDocument.getURL();
}
final ParsedURL newURI = new ParsedURL(oldURI, url);
String theUrl = newURI.toString();
fragmentIdentifier = newURI.getRef();
loader = new DocumentLoader(userAgent);
nextDocumentLoader = new SVGDocumentLoader(theUrl, loader);
nextDocumentLoader.setPriority(Thread.NORM_PRIORITY);
Iterator it = svgDocumentLoaderListeners.iterator();
while (it.hasNext())
{
nextDocumentLoader
.addSVGDocumentLoaderListener((SVGDocumentLoaderListener) it.next());
}
documentLoader = nextDocumentLoader;
nextDocumentLoader = null;
documentLoader.run();
}
For anyone interested, I found that I can call Batik's
DocumentLoader.loadDocument(URL url, InputStream is)
with the setUseCaches flag as false. Not only does this load the image, but it also removes it from the cache accordingly. Though not the best solution in the sense that it would be nice for JWS to honor my HTTP headers, this work-around is good enough.
Related
I'm trying to set up an API that generate PDF from web page (provided as URL). The API is gotenberg from thecodingmachine. I have it on Docker, it works just fine, I can't generate PDF through http request send with curl (for now I'm just trying to make it work, so I use the request provided as example in the documentation)
Now I am trying to make it work with my groovy/grails app. So I'm using the java tools to make the request.
Now here is my problem : the PDF file I get is blank (my app opend directly in my browser). It do has the right content, if I open it with the text editor, it's not empty, and it has almost the same content as the one I make using the curl request (which isn't blank).
I am 99% sure the problem come from the encoding. I tried changing the InputStreamReader encoding parameter, but it doesn't change anything. Here I put "X-MACROMAN" because that the encoding inside the pdf file that isn't blank, but it still doesn't change.
Here is my code :
static def execute(def apiURL)
{
def httpClient = HttpClients.createDefault()
// Request parameters and other properties.
def request = new HttpPost(apiURL)
MultipartEntityBuilder builder = MultipartEntityBuilder.create()
builder.addTextBody("remoteURL", 'https://google.com')
builder.addTextBody("marginTop", '0')
builder.addTextBody("marginBottom", '0')
builder.addTextBody("marginLeft", '0')
builder.addTextBody("marginRight", '0')
HttpEntity multipart = builder.build()
request.setEntity(multipart)
def response = httpClient.execute(request)
BufferedReader rd = new BufferedReader(
new InputStreamReader(response.getEntity().getContent(), "X-MACROMAN"))
StringBuffer result = new StringBuffer()
String line = ""
Boolean a = Boolean.FALSE
while ((line = rd.readLine()) != null) {
if(!a){
a = Boolean.TRUE
}
else {
result.append("\n")
}
result.append(line)
}
return result
I am 99% sure the problem come from the encoding. I tried changing the InputStreamReader encoding parameter, but it doesn't change anything. Here I put "X-MACROMAN" because that the encoding inside the pdf file that isn't blank, but it still doesn't change.
Did I made myself clear ? And does those who understands has any ideas why my PDFs are blank ?
I have a requirement that consists on uploading files through other system to sensenet.
I'm trying to use the Sensenet Client API to upload files but I'm having difficult using the examples documented on the follow links:
Client Library (the code runs well but the file doesn't appear on Sensenet)
Common API Calls (I'm having trouble to compile the code... to instantiate the BinaryData object)
Beside this, I need for each uploading file define the "Modified By" that I specify in my code and not the user that I use to authenticate me in the API.
I think rewriting the ModifiedBy field is an edge case (or a small hack) but it is possible without any magic (see the code). The easiest way is a POST followed by a PATCH, that is perfectly managed by the SenseNet.Client (the code uses a local demo site):
static void Main(string[] args)
{
ClientContext.Initialize(new[]
{new ServerContext {Url = "http://localhost", Username = "admin", Password = "admin"}});
var localFilePath = #"D:\Projects\ConsoleApplication70\TestFileFromConsole1.txt";
var parentPath = "/Root/Sites/Default_Site/workspaces/Document/londondocumentworkspace/Document_Library";
var fileName = "TestFileFromConsole1.txt";
var path = parentPath + "/" + fileName;
var userPath = "/Root/IMS/BuiltIn/Demo/ProjectManagers/alba";
using (var stream = new FileStream(localFilePath, FileMode.Open))
Content.UploadAsync(parentPath, fileName, stream).Wait();
Console.WriteLine("Uploaded");
Modify(path, userPath).Wait();
Console.WriteLine("Modified");
Console.Write("Press <enter> to exit...");
Console.ReadLine();
}
// Rewrites the ModifiedBy field
private static async Task Modify(string path, string userPath)
{
var content = await Content.LoadAsync(path);
content["ModifiedBy"] = userPath;
await content.SaveAsync();
}
I need to navigate to a web site that ultimately contains a .pdf file and I want to save that file locally. I am using CEFSharp to do this. The nature of this site is such that once the .pdf appears in the browser, it cannot be accessed again. For this reason, I was wondering if once you have a .pdf displayed in the browser, is there a way to access the source for that file in the cache?
I have tried implementing IDownloadHandler and that works, but you have to click the save button on the embedded .pdf. I am trying to get around that.
OK, here is how I got it to work. There is a function in CEFSharp that allows you to filter an incoming web response. Consequently, this gives you complete access to the incoming stream. My solution is a little on the dirty side and not particularly efficient, but it works for my situation. If anyone sees a better way, I am open for suggestions. There are two things I have to assume in order for my code to work.
GetResourceResponseFilter is called every time a new page is downloaded.
The PDF is that last thing to be downloaded during the navigation process.
Start with the CEF Minimal Example found here : https://github.com/cefsharp/CefSharp.MinimalExample
I used the WinForms version. Implement the IRequestHandler and IResponseFilter in the form definition as follows:
public partial class BrowserForm : Form, IRequestHandler, IResponseFilter
{
public readonly ChromiumWebBrowser browser;
public BrowserForm(string url)
{
InitializeComponent();
browser = new ChromiumWebBrowser(url)
{
Dock = DockStyle.Fill,
};
toolStripContainer.ContentPanel.Controls.Add(browser);
browser.BrowserSettings.FileAccessFromFileUrls = CefState.Enabled;
browser.BrowserSettings.UniversalAccessFromFileUrls = CefState.Enabled;
browser.BrowserSettings.WebSecurity = CefState.Disabled;
browser.BrowserSettings.Javascript = CefState.Enabled;
browser.LoadingStateChanged += OnLoadingStateChanged;
browser.ConsoleMessage += OnBrowserConsoleMessage;
browser.StatusMessage += OnBrowserStatusMessage;
browser.TitleChanged += OnBrowserTitleChanged;
browser.AddressChanged += OnBrowserAddressChanged;
browser.FrameLoadEnd += browser_FrameLoadEnd;
browser.LifeSpanHandler = this;
browser.RequestHandler = this;
The declaration and the last two lines are the most important for this explanation. I implemented the IRequestHandler using the template found here:
https://github.com/cefsharp/CefSharp/blob/master/CefSharp.Example/RequestHandler.cs
I changed everything to what it recommends as default except for GetResourceResponseFilter which I implemented as follows:
IResponseFilter IRequestHandler.GetResourceResponseFilter(IWebBrowser browserControl, IBrowser browser, IFrame frame, IRequest request, IResponse response)
{
if (request.Url.EndsWith(".pdf"))
return this;
return null;
}
I then implemented IResponseFilter as follows:
FilterStatus IResponseFilter.Filter(Stream dataIn, out long dataInRead, Stream dataOut, out long dataOutWritten)
{
BinaryWriter sw;
if (dataIn == null)
{
dataInRead = 0;
dataOutWritten = 0;
return FilterStatus.Done;
}
dataInRead = dataIn.Length;
dataOutWritten = Math.Min(dataInRead, dataOut.Length);
byte[] buffer = new byte[dataOutWritten];
int bytesRead = dataIn.Read(buffer, 0, (int)dataOutWritten);
string s = System.Text.Encoding.UTF8.GetString(buffer);
if (s.StartsWith("%PDF"))
File.Delete(pdfFileName);
sw = new BinaryWriter(File.Open(pdfFileName, FileMode.Append));
sw.Write(buffer);
sw.Close();
dataOut.Write(buffer, 0, bytesRead);
return FilterStatus.Done;
}
bool IResponseFilter.InitFilter()
{
return true;
}
What I found is that the PDF is actually downloaded twice when it is loaded. In any case, there might be header information and what not at the beginning of the page. When I get a stream segment that begins with %PDF, I know it is the beginning of a PDF so I delete the file to discard any previous contents that might be there. Otherwise, I just keep appending each segment to the end of the file. Theoretically, the PDF file will be safe until you navigate to another PDF, but my recommendation is to do something with the file as soon as the page is loaded just to be safe.
Chrome and Firefox don't render Font-Awesome's WOFF/TTF, even if they download them from HttpListener, that said, Safari on iOS is rendering Font-Awesome correctly.
I am sending HTTP response using .NET's HttpListener class as follows:
private void Send(HttpListenerContext context, byte[] response, string contentType)
{
context.Response.StatusCode = (int)HttpStatusCode.OK;
context.Response.ContentEncoding = Encoding.UTF8;
context.Response.ContentType = contentType;
context.Response.ContentLength64 = response.Length;
context.Response.AddHeader("Server", SERVER);
if (response == null || response.Length == 0)
{
logger.Error("Send: Engine generated null or empty content");
context.Response.StatusCode = (int)HttpStatusCode.NotFound;
return;
}
using (var s = context.Response.OutputStream)
{
s.Write(response, 0, response.Length);
}
}
Is there another encoding type (other than UTF8) for WOFF? or is there something that I have to take care of in Chrome or Firefox?
Any help or pointer appreciated, thanks.
In my own implementation, I leave out the ContentEncoding header all together when serving a font or binary.
This should work:
context.Response.ContentLength64 = response.Length;
context.Response.ContentType = "application/x-font-woff";
context.Response.OutputStream.Write(response, 0, response.Length);
context.Response.OutputStream.Close();
The problem was I had all the www content as Embedded Resource, and I created a method to convert those Embedded Resource Stream to a byte array by first converting that to a string using UTF-8 encoding.
So this stackoverflow question helped me to pinpoint the root cause. Once I converted the Embedded Resource Stream directly to a byte array, Chrome started showing Font-Awesome fonts correctly!
How do I open an existing file on the server when a user clicks an actionlink? The following code works for downloading a file but I want to open a new browser window, or tab, and display the file contents.
public ActionResult Download()
{
return File(#"~\Files\output.txt", "application/text", "blahblahblah.txt");
}
You must add "inline" for a new tab.
byte[] fileBytes = System.IO.File.ReadAllBytes(contentDetailInfo.ContentFilePath);
Response.AppendHeader("Content-Disposition", "inline; filename=" + contentDetailInfo.ContentFileName);
return File(fileBytes, contentDetailInfo.ContentFileMimeType);
The way you're using the File() method is to specify a file name in the third argument, which results in a content-disposition header being sent to the client. This header is what tells a web browser that the response is a file to be saved (and suggests a name to save it). A browser can override this behavior, but that's not controllable from the server.
One thing you can try is to not specify a file name:
return File(#"~\Files\output.txt", "application/text");
The response is still a file, and ultimately it's still up to the browser what to do with it. (Again, not controllable from the server.) Technically there's no such thing as a "file" in HTTP, it's just headers and content in the response. By omitting a suggested file name, the framework in this case may omit the content-disposition header, which is your desired outcome. It's worth testing the result in your browser to see if the header is actually omitted.
Use a target of blank on your link to open it in a new window or tab:
Download File
However, forcing the browser to display the contents is out of your control, as it entirely depends on how the user has configured their browser to deal with files that are application/text.
If you are dealing with text, you can create a view and populate the text on that view, which is then returned to the user as a regular HTML page.
please try this and replace your controller name and action name in html action link
public ActionResult ShowFileInNewTab()
{
using (var client = new WebClient()) //this is to open new webclient with specifice file
{
var buffer = client.DownloadData("~\Files\output.txt");
return File(buffer, "application/text");
}
}
OR
public ActionResult ShowFileInNewTab()
{
var buffer = "~\Files\output.txt"; //bytes form this
return File(buffer, "application/text");
}
this is action link which show in new blank tab
<%=Html.ActionLink("Open File in New Tab", "ShowFileInNewTab","ControllerName", new { target = "_blank" })%>
I can´t vote your answered as is useful, follow dow. Thanks very much !
public FileResult Downloads(string file)
{
string diretorio = Server.MapPath("~/Docs");
var ext = ".pdf";
file = file + extensao;
var arquivo = Path.Combine(diretorio, file);
var contentType = "application/pdf";
using (var client = new WebClient())
{
var buffer = client.DownloadData(arquivo);
return File(buffer, contentType);
}
}