Re: create web service inside GWT project
Hi Jeff,
I think I figured things out, thanks to your pointers.
I'll try to explain what I did in case someone with the same question
stumbles upon this thread.
First, I created a class that extends HttpServlet. Thats different
from the classes that are made to communicate with GWT-client.
HttpServlet is a fairly simple way to create a respons to a webquery.
See this page for some general info:
http://www.apl.jhu.edu/~hall/java/Servlet-Tutorial/Servlet-Tutorial-First-Servlets.html
Second, I used a library to simplify creating XML responses. I used
jdom. See this page for some info:
http://www.ibm.com/developerworks/java/library/j-jdom/
Then I edited web.xml so the app server will connect requests to a
certain URI to my newly created class:
servlet
servlet-nameMyJustCreatedExternalInterfaceImpl/servlet-name
servlet-classnet.arianprins.advsys.server.ExternalInterfaceImpl/
servlet-class
/servlet
servlet-mapping
servlet-nameMyJustCreatedExternalInterfaceImpl/servlet-name
url-pattern/advsys/ExternalInterfaceImpl/url-pattern
/servlet-mapping
Just in case someone is interested; I'll add my test-class at the
bottom.
I'm now going to research the best method to do xml requests in
vba / .net but that's for another group :-)
Jeff, thanks for taking the time to help me.
Arian.
---
public class ExternalInterfaceImpl extends HttpServlet {
public void init(ServletConfig config) throws ServletException {
// Initialise anything if neede
}
public void doGet(HttpServletRequest request, HttpServletResponse
response)
throws IOException, ServletException {
try {
// This gets the id in the request ie
http://www.x.com/ExternalInterfaceImpl?id=5
Integer eszId = Integer.parseInt(request.getParameter(id));
// Build some example xml:
Element carElement = new Element(car);
Document myDocument = new Document(carElement);
// Output the xml document:
try {
XMLOutputter outputter = new XMLOutputter();
response.setContentType(text/xml);
response.setHeader(Cache-Control, no-cache);
outputter.output(myDocument, response.getWriter());
} catch (java.io.IOException e) {
e.printStackTrace();
}
// id request variable didn't contain a valid integer:
} catch (NumberFormatException e) {
response.setContentType(text/xml);
response.setHeader(Cache-Control, no-cache);
response.getWriter().write(messageinvalid request:
+request.getParameter(id)+/message);
}
}
}
On 9 jul, 17:23, Jeff Chimene jchim...@gmail.com wrote:
Hi Arian,
I don't have a good answer for you, as I really don't do server-side Java.
I've got to believe that there are quite a few examples out there of
how a Java servlet can participate in CGI traffic on some arbitrary
port. Such CGI traffic is what a non-Java RPC client request looks like
to a CGI server. Your servlet is written in Java, but doesn't use GWT
Java RPC. IOW, this servlet doesn't extend and implement
RemoteServiceServlet. This doesn't change what the Office macro sends. I
could produce a Perl script that interacts with your Office macro, and
the macro would never know that it's not talking to a Java servlet.
Your servlet then decodes the request parameters and replies with a
CGI-compatible response.
BTW, the reference to .NET objects in my earlier post referred to the
client side as well as the server side. Although you're using Java on
the server side, I think you'll still need .NET classes for the client
(MS Office) side.
On 07/09/2010 07:19 AM, Arian Prins wrote:
Hi Jef,
Thanks for taking the time to answer my questions.
I'll try to remove the fuzziness.
I have already built a lot of objects using server side java, so I'm
not going to build any services using .NET. I've used the eclipse GWT
plugin and that takes care of everything needed to get the GWT-client
talking to the java objects on the server. Hence my misnomer GWT
server. It's java, it uses GWT-RPC (i presume) as a protocol to talk
to the client.
So now I have a complete server that talks to my client. Both created
in Java, both arranged through eclipse. Now I want to add some way for
an office macro (but actually it could be anything, eg. an rss feed
you want to publish) to query the server.
So I would need to use some java library to send incoming XHR requests
to a java object+method and I'd need to configure the server to
differentiate between requests coming from the GWT client and the XHR
requests coming from anywhere else.
I made a sketch of the different
parts:http://www.arianprins.net/downloads/advsys.gif
While i'm discussing my problems with you I think the solution lies in
these two questions:
- how to create an XHR service / servlet in java
Re: create web service inside GWT project
Hi Jeff, Just to explain my plan a little further: I'm building an application where the user normally interacts with the system using GWT in a browser (the most normal way of using GWT). But I'd also like to generate some documents (in MS-Word) using data and objects that are available in the GWT-server. There would probably be only a small number of methods that need to be available on the outside, so a very heavyweight library would be overkill. It all boils down to: I want to execute a function in a word-macro: String GetTheTextForThisWordDocument(documentId); :-) :-) XHR sounds good, but how can I get that to work? The way I think about it I would probably need to perform the following steps: - Create an object / methods that perform the function(s) that I want to be available (the GetTheText... method mentioned above); - Use some kind of library / construction that can make that object available to the outside world (just like GWT does in its own way). Is there some kind of standard XHR library? - Somehow configure the application server (in web.xml?) to respond to a certain URL using that library (example: http://localhost:8001/WordDocumentXHR) Those last two points I've never dealt with before (and I haven't found anything googling), so any advise would be appreciated. Arian. On 8 jul, 02:26, Jeff Chimene jchim...@gmail.com wrote: On 07/05/2010 02:28 PM, Arian Prins wrote: Hello people, I have a hard time figuring out what would be the best approach for my problem. I'd like to communicate some info from the server (side logic) to an MS-Office macro. I could always use ODBC to let the office macro query the database directly but that just feels like a kludge. I've got a lot of objects in my application in which a lot of processing is already implemented. So, I figure, the best way would be to create a web service (SOAP?) inside the gwt server-side implementation that can be queried by outside applications. I've done a lot of searching, but haven't really found any definitive way that would be best. Should I use an existing RPC/SOAP/JSON library and try to integrate it into GWT's structure (how to configure web.xml? etc. etc.)? Is there something already provided by google or in de code projects? Any thoughts and tips would be greatly appreciated. Arian Prins. Hi Arian, I've written some fairly complex Office macros. I'm not sure where GWT fits into your application. In your case, the client side is MS Office macros, not a browser JavaScript instance. The server side can be whatever you wish. You will probably want to use XMLHTTPRequests (XHR) to communicate with the server; I think SOAP is a bit heavy-handed to implement in an Office macro. I doubt RPC will work for you, as the serialization logic is also a bit much for an Office macro. This leaves JSON, application-specific XML (as opposed to the generalized SOAP DTD), CSV. If you are planning to use the Google App Engine, I'm not sure how to get Office macros to use Java RPC. I'm leaning towards the XHR solution: it's lightweight, can be tested independently of the macro environment, and straightforward to mock inside the macro environment. -- You received this message because you are subscribed to the Google Groups Google Web Toolkit group. To post to this group, send email to google-web-tool...@googlegroups.com. To unsubscribe from this group, send email to google-web-toolkit+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.
create web service inside GWT project
Hello people, I have a hard time figuring out what would be the best approach for my problem. I'd like to communicate some info from the server (side logic) to an MS-Office macro. I could always use ODBC to let the office macro query the database directly but that just feels like a kludge. I've got a lot of objects in my application in which a lot of processing is already implemented. So, I figure, the best way would be to create a web service (SOAP?) inside the gwt server-side implementation that can be queried by outside applications. I've done a lot of searching, but haven't really found any definitive way that would be best. Should I use an existing RPC/SOAP/JSON library and try to integrate it into GWT's structure (how to configure web.xml? etc. etc.)? Is there something already provided by google or in de code projects? Any thoughts and tips would be greatly appreciated. Arian Prins. -- You received this message because you are subscribed to the Google Groups Google Web Toolkit group. To post to this group, send email to google-web-tool...@googlegroups.com. To unsubscribe from this group, send email to google-web-toolkit+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.
