I am using SWFUpload to upload files to java servlet (spring framework). The problem is that the current web session is lost during file upload (it creates a new session). I read that it is a known bug and there are some workarounds somewhere but I can't find anything. Does anyone know how to make it work?
Thanks.
Have a look at this post on the SWFUpload forums. Adding ;jsessionid=XXX to the upload URL may work for you, or it may not; the exact cause of the problem appears unclear. Note that Flash uses the Wininet stack (same as IE), so if you are using a different browser you need to somehow get the session cookie (known to your browser) into the IE cookie.
Had this on the .NET platform as well. The problem is that the Flash Object runs in a different session context than your Java App (it's effectively treated like a new client). One way to get around all of this is to effectively have the object post any necessary information needed to commit the uploads back in the querystring.
The known bug you describe sounds like this one. If you have the time please sign up just to say "I have this problem too" so we can make it really clear to Adobe that it is affecting a lot of people.
It is hard to give an example of the best way to do it for your particular situation as I don't know much about spring.
That said, the usual way to work around it is to append a GET variable with the session to the upload url, then take that and manually set it to be the session on the server-side.
Here's another SO thread about this problem that has a good answer (unfortunately not specific to java+spring, but might give you a better idea).
Hopefully that's enough detail to get you off to a good start.
Related
I am coding an intricate method in a Spring Controller that takes as input request.getParameterMap(). In developing the method iteratively, each time I make a tweak, I have to Deploy, and then go through the steps on the web form.
That process can take minutes, just to tweak a small code change.
Are there any tricks or methods to speed up this process? All I really need is the input from request.getParameterMap(). Can I serialize that Map data somehow, and re-use it?
I am using Netbeans, if that is relevant.
In my experience the best is to setup a JUnit test, which doesn't use the web server at all, but just instantiates the controller, calls the method and checks the result.
Since your controller wasn't written from the ground up for this kind of approach, it might be quite some work to get this going at this stage. If you post the method in question we might help with this.
The next best thing is setting up an integration test, which starts up the application server, executes the request (possibly through the actual web gui using selenium or something).
Still a lot of work, but the difficulties are less dependent on the current workstyle.
As a final work around you can try to make the roundtrip for a manual test faster. There might be IDE dependent possibilities so you would have to let us know about the IDE in use.
I haven't tested it, but many people praise JRebel for this kind of thing, so you might want to give it a try.
If you don't want to fill the web form again and again try Jmeter(It's a free load testing tool).
Create a test plan with -> set number of threads to 1 --> http request sampler -> set method to post and add post parameters. Once everthing is setup fire the request
please check this link below for reference
http://community.blazemeter.com/knowledgebase/articles/65142-the-new-http-sampler-in-jmeter-2-6
I have a third party application which has lot of servlets and jsp. I wanted to debug that by putting breakpoints on my local jboss server. How do I know that, for a particular request, the request is being processed by particular java classes and jsp, so that I can put breakpoints in the right files? I am thinking of going through the code, before setting the breakpoints, to know where to put them. But I feel this is not an efficient way to do it (as it is a very big application). Can you please suggest if there is any better way to do this?
Thanks in advance.
The web.xml file contains servlet-mapping elements indicating which servlets are mapped to which URLs. So if you know the URL, you should easily find the corresponding servlet. Now you can read the servlet code to see which other classes are involved.
I think fastest way for debugging applications like this, is profiling application for specific usecase, in this way you can understand which classes used for this scenario and after finding classes, you can debug these classes.
for profiling application there are lots of tools.
commercial: Yourkit, JProfiler, JProbe
open source:VisualVM, Javacalltracer (create run-time sequence diagram)
before asking, please understand that my english is not good.
I'm using Class.forName(...) class in a servlet programming. when I access the servlet, I get a row of detailed controller information from Database indicating which controller to use.
This is Class.forName(...) I coded:
Class c = Class.forName(row.getControllerInfo);
c.newInstance();
This works fine, but there's a problem, i'm using Eclipse. The problem is that when I modified the Controller file, the changed contents were not applied to the server.,,.
Probably the easiest way is not to support dynamic loading. Much better to achieve something like dynamic update by supporting multiple servers. For development, you could get around redeploy delays by using JRebel (there might be others).
If you really do want dynamic loading of classes then the answer is "class loaders". I suggest having a look at those, and come back with any specific questions.
If I understood your problem true,
When you change any file of your project, you must deploy your project to server. If you use server from eclipse, republish may solve your problem.
have you tried clean - re-built and then deploying your application?
I am validating my login form. I have created a validation.xml, added the plugin in struts-config.xml, created ApplicationResource.properties file etc. I have done all the necessary things for validation frame work, my application is also running without errors but it is not validating the data. I have rechecked many times. Please anyone tell me where should I check for probable errors.
Thanks
If as you say, the application is running without errors and your data is not validated, then I think that the validator plugin isn't picked up by your application. That could occur if your login form is not extending ValidatorForm but your plain ActionForm. Are you extending ValidatorForm?
Recheck your code against a Struts validator guide. Even if you already did that, there is still something you might have missed or misunderstood.
Have a colleague or friend look at it. Someone with a fresh clean perspective might notice something you missed because you stared to long at your own code.
If that is not possible you can always delete everything (that is to be read as: save current solution somewhere then get a clean copy from source control) and start from scratch. If then it works, you can compare with what you saved from your initial solution and spot the difference.
I'm playing with a GWT/GAE project which will have three different "pages", although it is not really pages in a GWT sense. The top views (one for each page) will have completely different layouts, but some of the widgets will be shared.
One of the pages is the main page which is loaded by the default url (http://www.site.com), but the other two needs additional URL information to differentiate the page type. They also need a name parameter, (like http://www.site.com/project/project-name. There are at least two solutions to this that I'm aware of.
Use GWT history mechanism and let page type and parameters (such as project name) be part of the history token.
Use servlets with url-mapping patterns (like /project/*)
The first choice might seem obvious at first, but it has several drawbacks. First, a user should be able to easily remember and type URL directly to a project. It is hard to produce a human friendly URL with history tokens. Second, I'm using gwt-presenter and this approach would mean that we need to support subplaces in one token, which I'd rather avoid. Third, a user will typically stay at one page, so it makes more sense that the page information is part of the "static" URL.
Using servlets solves all these problems, but also creates other ones.
So my first questions is, what is the best solution here?
If I would go for the servlet solution, new questions pop up.
It might make sense to split the GWT app into three separate modules, each with an entry point. Each servlet that is mapped to a certain page would then simply forward the request to the GWT module that handles that page. Since a user typically stays at one page, the browser only needs to load the js for that page. Based on what I've read, this solution is not really recommended.
I could also stick with one module, but then GWT needs to find out which page it should display. It could either query the server or parse the URL itself.
If I stick with one GWT module, I need to keep the page information stored on server side. Naturally I thought about sessions, but I'm not sure if its a good idea to mix page information with user data. A session usually lives between user login and logout, but in this case it would need different behavior. Would it be bad practise to handle this via sessions?
The one GWT module + servlet solution also leads to another problem. If a user goes from a project page to the main page, how will GWT know that this has happened? The app will not be reloaded, so it will be treated as a simple state change. It seems rather ineffecient to have to check page info for every state change.
Anyone care to guide me out of the foggy darkness that surrounds me? :-)
I'd go with History tokens. It's the standard way of handling such situations. I don't understand though, what you mean by "It is hard to produce a human friendly URL with history tokens" - they seem pretty human friendly to me :) And if you use servlets for handling urls, I think that would cause the whole page to be reloaded - something which I think you'd rather want to avoid.
Second, I'm using gwt-presenter and
this approach would mean that we need
to support subplaces in one token,
which I'd rather avoid.
If you are not satisfied with gwt-presenter (like I was :)), roll out your own classes to help with MVP - it's really easy (you can start from scratch or modify the gwt-presenter classes) and you'll get a solution suited to your needs. I did precisely that, because gwt-presenter seemed to "complicated"/complex to me - to generic, when all I needed was a subset of what it offered (or try to offer).
As for the multiple modules idea - it's a good one, but I'd recommend using Code Splitting - this type of situation (pages/apps that can be divided into "standalone" modules/blocks) is just what it's meant to be used for, plus you bootstrap your application only once, so no extra code downloaded when switching between pages. Plus, it should be easier to share state that way (via event bus, for example).
Based on what you have posted I presume you come from building websites using a server side framework: JSP, JSF, Wicket, PHP or similar. GWT is not the solution for building page-based navigational websites, like you would with the aforementioned frameworks. With GWT, you load a webapp in the browser and stay there. Handle user events, talk with the server and update widgets; using gwt-presenter is a good thing here as you are forced to think about separation of controller logic and view state.
You can really exploit all features of GWT to build a high-performance app-in-the-browser, but it is definately not meant for building websites (using hyperlinked pages that transfer request parameters via the server session).
This is by far the most widely asked question about GWT here # StackOverflow :)
"How do I define pages and navigation between them in GWT?" Short answer: "You don't."
Use Wicket instead, it runs on the App Engine just fine and enables you to define page bookmarks and all stuff you mentioned above. Look here: http://stronglytypedblog.blogspot.com/2009/04/wicket-on-google-app-engine.html