there I am Currently using the cpp-httplib library for file transfer. I am very new and have little understanding of this library. The file upload from the client-side part was easy to understand and also had soln for it on this site too. But there aren't any references to download files from the server. Please help.
httpServer_.Get("/Download/filename", [&](const httplib::Request& _req, httplib::Response& _res)
{
_res.set_content("filedata", "multipart/form-data");
});
Related
I need to create a simple web service (being the "server"). The goal is to provide some data I do read in an Qt / C++ application as JSON data. Basically a JavaScript application in the browser shall read its data from the Qt app. It is usually a single user scenario, so the user runs a Google Maps application in her browser, while additional data come from the Qt application.
So far I have found these libs:
Qxt: http://libqxt.bitbucket.org/doc/0.6/index.html but being a newbie on C++/Qt I miss some examples. Added: I have found one example here
gSoap: http://www.cs.fsu.edu/~engelen/soap.html has more examples and documentation and also seems to support JSON
KD SOAP: http://www.kdab.com/kdab-products/kd-soap/ with no example as far as I can tell, docu is here
Qt features itself, but it is more about acting as a client: http://qt-project.org/videos/watch/qt-networking-web-services
Checking SO gives me basically links to the above libs
webservice with Qt with an example I do not really get.
How to Create a webservice by Qt
So basically I do have the following questions:
Which lib would you use? I want to keep it as simple as possible and would need an example.
Is there another (easy!) way to provide the JSON data to the JavaScript Web page besides the WebService?
-- Edit, remarks: ---
Needs to be application intrinsic. No web server can be installed, no extra run time can be used. The user just runs the app. Maybe the Qt WebKit could be an approach....
-- Edit 2 --
Currently checking the tiny web servers as of SO " Qt HTTP Server? "
As of my tests, currently I am using QtWebApp: http://stefanfrings.de/qtwebapp/index-en.html This is one of the answers of Edit 2 ( Qt HTTP Server? )
Stefan's small WebServer has some well documented code, is written in "Qt C++" and easy to use, especially if you have worked with servlets already. Since it can be easily integrated in my Qt project, I'll end up with an internal WebServer.
Some demo code from my JSON tests, showing that generating the JSON content is basically creating a QString.
void WebServiceController::service(HttpRequest& request, HttpResponse& response) {
// set some headers
response.setHeader("Content-Type", "application/json; charset=ISO-8859-1");
response.setCookie(HttpCookie("wsTest","CreateDummyPerson",600));
QString dp = WebServiceController::getDummyPerson();
QByteArray ba = dp.toLocal8Bit();
const char *baChar = ba.data();
response.write(ba);
}
If someone has easy examples with other libs to share, please let me know.
QByteArray ba = dp.toLocal8Bit();
const char *baChar = ba.data();
You don't need to convert the QByteArray to char array. Response.write() can also be called with a QByteArray.
By the way: qPrintable(dp) is a shortcut to convert from QString to char array.
I am trying to do a JSON Restful web service in C/C++.
I have tried Axis2/C and Staff, which work great for XML serialization/deserialization but not for JSON.
You might want to take a look at Casablanca introduced in Herb Sutter's blog.
there are a small number of libraries that support creating rest services with c, e.g. restinio:
#include <restinio/all.hpp>
int main()
{
restinio::run(
restinio::on_this_thread()
.port(8080)
.address("localhost")
.request_handler([](auto req) {
return req->create_response().set_body("Hello, World!").done();
}));
return 0;
}
try https://github.com/babelouest/ulfius great library to build C/C++ Restful APIs. can support all platforms: Linux, FreeBSD, Windows and others
Try ngrest. It's a simple but fast C++ RESTful JSON Web Services framework. It can be deployed on top of Apache2, Nginx or own simple http server.
Regarding Axis2/C with JSON. It's seems that official Axis2/C no longer maintained. So Axis2/C become obsolete (but still works).
JSON support for Axis2/C is available in axis2c-unofficial project.
There are an installation manuals on how to install Axis2/C with JSON support under Linux, Windows using binary package, Windows from source code.
You can try it with WSF Staff using Customers (REST) example in JSON mode (which is available from staff/samples/rest/webclient directory of staff source code).
You could look at ffead-cpp. Apart from providing support for json and restfull web services it also includes more features. This framework may be too heavy weight for your situation though.
For C++ web service, I am using the following stack:
ipkn/crow C++ micro web framework
nlohmann/json for json serialization/deserialization.
Take a look at Oat++
It has:
URL routing with URL-parameters mapping
Support for Swagger-UI endpoint annotations.
Object-Mapping with JSON support.
Example endpoint:
ENDPOINT("GET", "users/{name}", getUserByName, PATH(String, name)) {
auto userDto = UserDto::createShared();
userDto->name = name;
return createDtoResponse(Status::CODE_200, userDto);
}
Curl:
$ curl http://localhost:8000/users/john
{"name":"john"}
You may want to take a look at webcc.
It's a lightweight C++ HTTP client and server library for embedding purpose based on Boost.Asio (1.66+).
It's quite promising and actively being developed.
It includes a lot of examples to demonstrate how to create a server and client.
There is a JIRA project resolved the support of JSON in AXIS2/C .
I implemented in my project and I managed with the writer (Badgerfish convention) but still I am trying to manage with the reader.It seems more complicated managing with the stack in the memory.
JSON and JSONPath are supported for both C and C++ in gsoap with a new code generator and a new JSON API to get you started quickly.
Several JSON, JSON-RPC and REST examples are included. Memory management is automatic.
The code generator can be useful. Take for example the json.org menu.json snippet:
{ "menu": {
"id": "file",
"value": "File",
"popup": {
"menuitem": [
{"value": "New", "onclick": "CreateNewDoc()"},
{"value": "Open", "onclick": "OpenDoc()"},
{"value": "Close", "onclick": "CloseDoc()"}
]
}
}
}
The gsoap command jsoncpp -M menu.json generates this code to populate a JSON value:
value x(ctx);
x["menu"]["id"] = "file";
x["menu"]["value"] = "File";
x["menu"]["popup"]["menuitem"][0]["value"] = "New";
x["menu"]["popup"]["menuitem"][0]["onclick"] = "CreateNewDoc()";
x["menu"]["popup"]["menuitem"][1]["value"] = "Open";
x["menu"]["popup"]["menuitem"][1]["onclick"] = "OpenDoc()";
x["menu"]["popup"]["menuitem"][2]["value"] = "Close";
x["menu"]["popup"]["menuitem"][2]["onclick"] = "CloseDoc()";
Also reading parsed JSON values and JSONPath code can be generated by this tool.
EDIT
To clarify, the jsoncpp command-line code generator shows the API code to read and write JSON data by using a .json file as a template, which I found is useful to save time to write the API code to populate and extract JSON data. JSONPath query code can also be generated with this tool.
For web service in C, you can leverage library like ulfius, civetweb:
https://github.com/babelouest/ulfius
https://github.com/civetweb/civetweb/blob/master/docs/Embedding.md
For web service in C++, you can leverage library like libhv, restbed:
https://github.com/ithewei/libhv
https://github.com/Corvusoft/restbed
I currently store text to speech mp3 files as varbinary(max) in the database. what I want to do is play those audio files using the embed tag where the source is ashx file that will recieve the id of the database record and write the byte array.
My ashx file has the following code
byte[] byteArray = ttsMessage.MessageContents;
context.Response.Buffer = true;
context.Response.Clear();
context.Response.ClearContent();
context.Response.ClearHeaders();
context.Response.ContentType = "audio/mpeg";
context.Response.OutputStream.Write(byteArray, 0, byteArray.Length);
context.Response.End();
The call from the aspx page is as follows
Panel5.Controls.Add(new LiteralControl(String.Format("<embed src='/TestArea/PreviewWav.ashx?source={0}' type='audio/mpeg' height='60px' width='144px'/>", ttsMessage.Id.ToString())));
I have gotten this to work with the following
Panel5.Controls.Add(new LiteralControl(String.Format("<audio controls='controls' autoplay='autoplay'><source src='/TestArea/PreviewWav.ashx?source={0}' type='audio/x-wav' /></audio>", ttsMessage.Id.ToString())));
Using the audio tag but cannot seem to get it to work with the embed tag.
I am using IE9/VS2010
Any ideas?
I think the wrong thing with embed tag is that...
Embed tag call a plugin like winmediaplayer ocx than handler firstly called from web page than media plugin get the ashx url than it started to call handler.
But web page's request and mediaplayer plugin's requests are diffent so if you check users Authentication or some other header information it fails.
You can easily see that on fiddler utility. On fiddler top-right side shows the request info. there is a user-agent part. Look it carefully.
How many requests happen from your handler,notice them. What are the differs. for each reqs.
If you have this issue,
You may use a ticket system or redirect a safety area for download without header or other request checks. Sadly web page requst cannot complately transfer media player and others.
hope helps
I'm trying to use the libcurl in a C/C++ application to post files to DropBox.
I would like to use the "/files (POST)" API as documented here...
https://www.dropbox.com/developers/reference/api#files-POST
I am having problems with properly authenticating (OAuth) this call. It is unclear to me how to properly create the authentication signature.
From some a sample I saw, it looked like they were reading in the whole file to create the HMAC-SHA1 encoding on. This seems problematic on large files.
Does anyone have experience or insight using this API or something similar?
I have just use the libouth and libcurl to get information from sina weibo. here is my example for you refer. you can also refer the liboauth test programmer in the tests dir, oauthtest.c
if (use_post)
{
req_url = oauth_sign_url2(test_call_uri, &postarg, OA_HMAC, NULL, c_key, c_secret, t_key, t_secret);
reply = oauth_http_post(req_url,postarg);
}
I suggest using BOOST ASIO . Makes uploading and downloading a breeze.
Hey, I've got this nice little piece of code, much like all the other versions of this method of upload using WSS WebServices. I've got one major problem though - once I have uploaded a file into my doc list, and updated the list item to write a comment/description, the file is stuck there. What I mean is that this method will not overwrite the file once I've uploaded it. Nobody else out there seems to have posted this issue yet, so .. anyone?
I have another version of the method which uses a byte[] instead of a Stream .. same issue though.
Note: I have switched off the 'require documents to be checked out before they can be edited' option for the library. No luck tho .. The doc library does have versioning turned on though, with a major version being created for each update.
private void UploadStream(string fullPath, Stream uploadStream)
{
WebRequest request = WebRequest.Create(fullPath);
request.Credentials = CredentialCache.DefaultCredentials; // User must have 'Contributor' access to the document library
request.Method = "PUT";
request.Headers.Add("Overwrite", "t");
byte[] buffer = new byte[4096];
using (Stream stream = request.GetRequestStream())
{
for (int i = uploadStream.Read(buffer, 0, buffer.Length); i > 0; i = uploadStream.Read(buffer, 0, buffer.Length))
{
stream.Write(buffer, 0, i);
}
}
WebResponse response = request.GetResponse(); // Upload the file
response.Close();
}
Original credits to: http://geek.hubkey.com/2007/10/upload-file-to-sharepoint-document.html
EDIT -- major finding .. when I call it from my nUnit test project it works fine. It seems it only fails when I call it from my WCF application (nUnit running under logged on user account, WCF app has app pool running under that same user -- my account, which also has valid permissions in SharePoint).
Nuts. "Now where to start?!", I muses to myself.
SOLVED -- I found a little bug - the file was being created in the right place, but the update path was wrong.. I ended up finding a folder full of files with many, many new versions.. doh!
Why not use the out-of-the-box SharePoint webservice, Lists.asmx? You'll find it in
http://SITEURL/___vti_bin/Lists.asmx
Edit, I checked out the link and it seems you are calling the out of the box web service. This has got be versioning related then. Can you check out the different versions that exist in the doc lib of the specific file? see if it perhaps gets added as a minor version through the service?
Have you tried using a capital T? SharePoint's webdav header processing is not very likely to be case-sensitive, but the protocol does specify a capital T. Oh, and what is the response? A 412 error code or something altogether different?