Ok, basically I have a game that I want to be able to upload and download data (highscores) so the user can see it.
My trouble is that I don't know how to upload their score to the server. I would not know where to start with making the program download the information (I want it to only download the needed information. In the past I have had to download an entire website to scan it for the needed information!).
If this question has already been asked, I'm sorry but I have searched for answer for over 2 hours now!
HttpRequest needs to be used here. You can send data (JSON recommended) from your JAVA code to the server, and the server stores it in DB. This topic is too broad, so I recommend you to look through HttpRequest first.
Ok here's how this works :
You'll have 3 main components - JSP(because you tagged Java), Servlet and
Java class.
JSP, the web page will be loaded on client machine and the other 2 will be on
server along with the db.
From JSP or the web page you'll make a request
(either synchronous or asynchronous).
synchronous : by submitting a form to the servlet
asynchronous : by calling servlet method without submitting any for(AJAX)
Now this request will either be for saving HighScore or retrieving HighScore,
therefore it will call the respective method from server(the servlet)
and which in turn will call methods from Java Class(DAO, data access object).
DOA will return the required value or will store the value depending
on the request.
You do not need to download any website and search data in it. Just make requests and handle responses.
Guide for servlets : http://www.tutorialspoint.com/servlets/
Related
So, I have my script page and I want to get an output that generates on this page. It could've been done with default http client but the problem is that google requires authorization to access this page.
So how can I do it right?
I also asked about this before but now I realize that my question wasn't clear.
It is possible to post web app page to be accessible by "anyone even anonymous". So no auth is needed
I am building a web application using Spring framework that requires users to make a payment. When the user posts a form, it redirects to Hp's payment website and processes the payments there before returning to my application. This method however leaves my applications vulnerable to security threats and form manipulations.
I now want to post the form to my server, validate users inputs and if necessary post data to hp's web server. I have already written a java code for posting a form from my code and getting the response back into a file from hp's site but am unable to figure out how to redirect the user to the hp website using the java form post. Can someone please help? I am new to Spring so am open to suggestions that would help me accomplish this task either using this method or another way to do so.
Thanks
Obviously you need to perform the redirect on the server side, not on the client side. Redirection is basically returning HTTP 302 with Location header pointing to new location. When browser receives such response it opens the URL in question rather than rendering the response like it is with 200.
If you can receive and validate your form all you have to do is send the redirect back to the browser. I don't know which web framework do you use. In servlets you simply say:
response.sendRedirect("http://www.example.com/payment/...");
In spring-mvc return the following string from your controller as opposed to a view name:
return "redirect:http://www.example.com/payment/...";
Can we read cookies using core-java, that has been written using .NET MVC code? I have not find any help how to read cookies using core java code?
More Background Details -
Actually we have a java desktop application and we are planning to launch that java desktop application using JWS and that is working absolutely fine.
The issue is -- we ask some user related information from user on web page and launch java desktop application using JWS. Now we would like to have that information provided by user on web page in our java application.
We have write that information into cookies and how can we read that information from java code ?
Yes, you can receive cookies that have been set by another application (as long as the path value in the cookie matches). Cookies are part of the HTTP protocol and it does not matter how thay were defined. The client sends them in future requests depending on the URL path.
To access cookies in Java, have a look at getCookies() in HttpServletRequest.
update
The cookies set by your web-application that launches the Java client will have been set in the context of the browser client. Cookies are added to a HTTP response and cached by the client receiving them.
In the case that you describe you cannot access the same server-session from the Java client without trickery.
The solution I would use is to generate a unique ID in the web-app that is passed as argument to the Java client which can in turn request the values needed from the other session using a fetch of a URL using the generated ID as parameter. (This in essence connects the two HTTP sessions as being part of the same user process.)
For instance you could use a HttpURLConnection and a URL like <web-app>/data?id=<ID> to fetch/download the values as XML from your web application.
Core-java? Then try java.net.*:
A cookie is just a header line with "Set-Cookie: " before the URL content.
http://www.hccp.org/java-net-cookie-how-to.html
I have a web application in which one of the workflows, users can download files that are dynamically generated. The input is a form which has parameters needed to generate the file.
My current solution is to let them submit this form & on the servlet side I change the response header - content disposition to be an attachment & also provide an appropriate mime-type.
But I find this approach to be inadequate. Because there are chances that the generation of file can take a very long time, in such cases after a certain timeout I directly get 500 or 503 errors in the browser. I guess this is to be expected for the current approach.
I want my workflow to be flexible enough to tell the users as soon as they submit the form that it might take time for the file to generate & that we will display the link to the file as soon as it is ready. I guess I can also email the file or this message to them, but this is not ideal.
Can you guys suggest me an approach for this problem? Should I be more specific in providing information? Any help appreciated.
If you want to do this synchronously (i.e. make the user wait for the document to be ready rather than have them go off and do other things while waiting) a traditional approach is to bring them to a "report loading" page.
This would be a page that:
1) informs them that the report is loading.
2) refreshes itself (either using the meta refresh tag or javascript)
3) upon refresh, checks to see if the report is ready and either:
a) goes back to step 1 if it isn't ready
b) gives them the document if it is ready.
Synchronous is kind of old-school, but your question sounded like that was the approach you wanted.
Asynchronous approaches would include:
Use Ajax to make a link to the document appear on the page once it is ready.
Have a separate page that shows previously generated documents. The use can go to this page at their leisure, and, meanwhile, they can browse the rest of the site. This requires keeping a history of generated documents.
As you suggested, send it via e-mail.
You can make an asynchronous Ajax Call to the server with the form data instead of submiting the form direct.
On the server you create a temp file and return a link to the client with the download URL.
After submitting the answer via Javascript you can show the user a hint, that the download link will appear in a minute. Don't forget to cleanup the temp file!
For submitting the Ajax Call I would suggest using an Javascript Framework. Have a look at JQuery:
http://api.jquery.com/category/ajax/
This problem relates to the Restlet framework and Java
When a client wants to discover the resources available on a server - they must send an HTTP request with OPTIONS as the request type. This is fine I guess for non human readable clients - i.e. in code rather than a browser.
The problem I see here is - browsers (human readable) using GET, will NOT be able to quickly discover the resources available to them and find out some extra help documentation etc - because they do not use OPTIONS as a request type.
Is there a way to make a browser send an OPTIONS/GET request so the server can fire back formatted XML to the client (as this is what happens in Restlet - i.e. the server response is to send all information back as XML), and display this in the browser?
Or have I got my thinking all wrong - i.e. the point of OPTIONS is that is meant to be used inside a client's code and not meant to be read via a browser.
Use the TunnelService (which by default is already enabled) and simply add the method=OPTIONS query parameter to your URL.
(The Restlet FAQ Q19 is a similar question.)
I think OPTIONS is not designed to be 'user-visible'.
How would you dispatch an OPTIONS request from the browser ? (note that the form element only allows GET and POST).
You could send it using XmlHttpRequest and then get back XML in your Javascript callback and render it appropriately. But I'm not convinced this is something that your user should really know about!