Compress(TInt aCompressionMethod,const TDesC8 data)
{
TInt compressionMethod = 0;
if(aCompressionMethod == 0)
compressionMethod = Z_DEFAULT_COMPRESSION;
iCompressor =CEZCompressor::NewLC(*this,Z_DEFAULT_COMPRESSION);
TRAPD(err, iCompressor->CompressL(cipher,text));
}
I am using compression using gzip method in symbian in client side and on server side server is in Java.
The problem is that on server side in Java gZip format is not matched exception is thrown.
I want to know the method I am using to compress string is correct or wrong, or whether I have to made change or server side has to change.
CEZCompressor will just give you the deflate-compressed data. It does not contain any gzip-specific header information. If your server-side java implementation needs to see that information, use the CEZGZipToFile class.
There's a nice example at Forum Nokia wiki.
Hope this helps. If not, please add details to your question. Currently it is a little bit on the vague side.
Related
I'm currently developing a simple application for querying/retrieving data on a PACS. I use DCMTK for this purpose, and a DCM4CHEE PACS as test server.
My goal is to implement simple C-FIND queries, and a C-MOVE retrieving system (coupled with a custom SCP to actually download the data).
To do so, I've created a CustomSCU class, that inherits the DCMTK DcmSCU class.
I first implemented a C-ECHO message, that worked great.
Then, I tried to implement C-FIND requesting, but I got the error "DIMSE No valid Presentation Context ID" (more on that in the next paragraph) from my application, but no other log from DCM4CHEE. I've then used the command tool findscu (from dcmtk) to see if there was some configuration issue but the tool just worked fine. So in order to implement my C-FIND request, I've read the source of findscu (here) and adapted it in my code (meaning that i'm not using DcmSCU::sendCFindRequest but the class DcmFindSU).
But now, i'm facing the same problem with C-MOVE request. My code is pretty straight-forward :
//transfer syntaxes
OFList<OFString> ts;
ts.push_back(UID_LittleEndianExplicitTransferSyntax);
ts.push_back(UID_BigEndianExplicitTransferSyntax);
ts.push_back(UID_LittleEndianImplicitTransferSyntax);
//sop class
OFString pc = UID_MOVEPatientRootQueryRetrieveInformationModel;
addPresentationContext(pc, ts);
DcmDataset query;
query.putAndInsertOFStringArray(DCM_QueryRetrieveLevel, "PATIENT");
query.putAndInsertOFStringArray(DCM_PatientID, <ThePatientId>);
OFCondition condition = sendMOVERequest(findPresentationContextID(pc, ""), getAETitle(), &query, nullptr);
return condition.good();
I've also tried using UID_MOVEStudyRootQueryRetrieveInformationModel instead of UID_MOVEPatientRootQueryRetrieveInformationModel, with the same result : my application shows the error
DIMSE No valid Presentation Context ID
As I understand, a presentation context is concatenation of one or more transfer syntax and one SOP class. I read that the problem could come from the PACS that won't accept my presentation contexts. To be sure, I used the movescu tool (from DCMTK). It worked, and I saw this in the logs from de server DCM4CHEE :
received AAssociatedRQ
pc-1 : as=<numbers>/Patient Root Q/R InfoModel = FIND
ts=<numbers>/Explicit VR Little Endian
ts=<numbers>/Explicit VR Big Endian
ts=<numbers>/Implicit VR Little Endian
That means that the movescu tool does a find before attempting an actual move ?
Therefore, I changed my application context creation with :
OFList<OFString> ts;
ts.push_back(UID_LittleEndianExplicitTransferSyntax);
ts.push_back(UID_BigEndianExplicitTransferSyntax);
ts.push_back(UID_LittleEndianImplicitTransferSyntax);
OFString pc1 = UID_FINDPatientRootQueryRetrieveInformationModel;
OFString pc = UID_MOVEPatientRootQueryRetrieveInformationModel;
addPresentationContext(pc1, ts);
addPresentationContext(pc, ts);
(also tried study root)
But this didn't do the trick.
The problem seems to lie on the client side, as findPresentationContextID(pc, ""); alwasy return 0, no matter what.
I don't feel like it's possible to adapt the code of the movescu tool, as it appears to be very complex and not adequat for simple retrieve operations.
I don't know what to try. I hope someone can help me understand what's going on. That's the last part of my application, as the storage SCP already works.
Regards
It looks like you are not negotiating the association with the PACS.
After adding the presentation contexts and before sending any command, the SCU must connect to the PACS and negotiate the PresentationContexts with DcmSCU::initNetwork and then DcmSCU::negotiateAssociation.
I am trying to make this working code to check if URL exists (coded Visual C++):
void urlexists()
{
try
{
LPCWSTR pfile(NULL);
HRESULT hRez = URLDownloadToFile(NULL, _T("http://google.com"), (pfile), 0, NULL);
if (hRez != 0)
return;
}
catch (...)
{
return;
}
}
and make it portable for linux distros. What should I do? I didn't found nothing on Internet
As far as the process goes, if you make a GET request to the URL, you will get a 200/OK code back if the resource exists. You will receive a 404 if it does not. Your file will be in the body of the request if the request succeeds. You then copy the request body to the file on disk.
There isn't a good way to make this portable without writing a libcurl, winhttp, and possibly a core foundation implementation. You either need to abstract this and write an implementation for each platform, or use a library that does it for you. There are a few options. Boost has an http client you could use. Also, the AWS SDK for C++ has an http implementation that will do this for you.
Your other option is to read the HTTP spec, open the socket yourself and make the request manually. Fair warning however, this is non-trivial especially if TLS is involved.
If you want to write it yourself, I recommend libcurl for your linux implementation. You are more than welcome to use the examples here as a starting point. https://github.com/awslabs/aws-sdk-cpp/tree/master/aws-cpp-sdk-core/include/aws/core/http
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'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.
I am a beginner in writing web application, so please co-operate if its a silly question. Our web application is hosted using tomcat 6. I have some C++ code to be executed in server when user click on corresponding button. Client side is written in html/JS and hosted using tomcat.
So, My problem is I dont know how this C++ code will be executed when a button is clicked in html page. Can anyone please help me?
[updated]
I can change from tomcat to any other server but code has to be in c++. So if you have any other server(wamp or smthing) or links to do the same. Please let me know
Tomcat, a Java Servlet container is definitely not the most appropriate vehicle to execute C++ code in. You could try to use JNI to make a servlet run the C++ code, but it seems to me that there are much easier and reliable ways, like good old CGI's. Tomcat can do CGI, as explained here, with some limitations and restrictions.
Update: I think we can agree that the CGI route is the way to go. Most webservers allow you to run cgi's, and it will definitely be simpler than with Tomcat. I also suggest you delegate the work of connecting your code to the web server to a library, like gnu cgicc (nice tutorial here) or cgic. A plain old WAMP (you'll just use the WA part here) and that sample code should get you up to speed in no time. The rest will be pretty standard Web development.
https://stackoverflow.com/questions/175507/c-c-web-server-library answers may well help you out.
Given that Tomcat is no longer a requirement, using a different http front end may well make your life easier.
If you do decide to use Tomcat Which C++ Library for CGI Programming? may help you pick a library.
Barring that, if you use Apache, you can write a plugin module itself, instead of CGI, which will give you much better performance. (Other web servers generally have similar plug-in methodologies also...)
Good Luck
I'm not sure any of these answers addressed the question. Coding a CGI using C++ would mean reading environment variables that are set by the web server, regardless of whether or not you use a third party library or which web server is run, including tomcat. The following example is a quick-and-dirty way to grab the most interesting input, the query string. If you are starting out, it's I think better to start with basics so if you decide to use some sort of external library it will seem less mystical. This should give you enough to hit google and work out what's happening.
#include <stdlib.h>
#include <iostream>
using namespace std;
int
main(int argc, char** argv)
{
string method = getenv("REQUEST_METHOD");
string query;
if (method == "GET")
query = getenv("QUERY_STRING");
else if (method == "POST")
cin >> query;
else
query = "Not sure what to do with method " + method;
cout << "Content-Type: text/html" << endl << endl
<< "<html>" << endl
<< query << endl
<< "</html>" << endl;
}
Note Content-Type in the output. That's a HTTP header. You can add any number of headers before the double endl. For a light bulb moment try changing Content-Type to text/plain.
Compile the example code to shiney_cpp_cgi, copy it to your cgi dir (for tomcat that's generally tomcat_root/webapps/ROOT/WEB-INF/cgi), then hit it with your browser as such to use the GET method:
myserver.mydomain:myport/cgi-bin/shiney_cpp_cgi?foo=bar
To send in a post request, use CURL as such:
curl --data 'foo=bar' myserver.mydomain:myport/cgi-bin/shiney_cpp_cgi
To serve C++ from tomcat, you can edit tomcat_root/conf/web.xml and change executable to an empty string. By default, tomcat will try to run your C++ as a perl script, which perl will (hopefully!) not be able to parse.
<servlet>
<servlet-name>cgi</servlet-name>
<servlet-class>org.apache.catalina.servlets.CGIServlet</servlet-class>
...
<init-param>
<param-name>executable</param-name>
<param-value></param-value>
</init-param>
...
</servlet>