I searched a lot regarding this topic but did not get any good answer.
Scenario:
We have Rest web service bases implementation in our project. Ideally frontEnd (Flex) call web service and backend send huge data point to frontEnd. Then frontEnd create chart of these data points and display to end user.
Our requirement is that user can export these charts and save as pdf file on the server. We are able to create JPG file from flex server and save as pdf file.
Problem occurs when end user has scheduled that chart report. Now that report can run at any time and may be browser is not opened at that time. So how backEnd will interact with frontEnd (flex) functions. Problems are:
browser is not opened so swf file is not loaded.
java/jsp need to interact with frontEnd(flex) as a reverseAjax so that frontEnd send JPG file back to server.
Does anybody face this issue before?
Is it somehow possible??
Asnwers/any leads are highly appreciated.
Please provide comments on this
Probably the only way to do this is to run a version of your Flex application (at least the charting part) on your server, and have your Java server interact with it.
I have faced a similar problem and have asked a similar question before. It is not very elegant, but what I mentioned before seems to be the only way to go.
Related
I am new to front end developing. I have so far a back-end program written in java with Eclipse that does all I want, saves the output in an object and prints it in the console (for my convenience).
My goal is to display this output information dynamically (meaning that the backend part of the program might update and send new output) in a webpage on a local server.
Hence I have "transformed" or "added" a Dynamical webpage to my Eclipse project using "Project Facets" in Eclipse Project Properties, and created an index.jsp file hosted on a tomcat server (See picture of the File organisation).
Ultimately, I want to have my index.jsp file open in my browser and when my backend program (which I assume I have to compile in an executable jar) detects changes , display those changes in the webpage. Also, I have a button on my webpage for which I would like to send information back to my backend program when it is clicked.
Should I use POST request in my backend with the URL of the index.jsp (although I don t want to display the information in a form, just regular text and images)?
or create a Javabean class in the webcontent/WEB-INF/ (if I can access and modify it dynamically from my backend) and then use that to get and set data from the jsp page?
or am I obliged to use something like Spring ?
I ve heard I should seperate backend and front end, but I don t really understand how they communicate dynamically !
Thank you for your help !
Seeing your project structure I believe you want to build a simple Java Web, you don't need to separate your front-end and back-end unless you want to build something complex.
I'm not quite sure about your experience with Java Web, but if this is your first time I suggest to learn more about Servlet because this is the fundamental in building Java Web project. After knowing how Java handle Http Request is up to you to build pure Java Web project, or using something like Spring MVC even if you want to build a separate front-end that communicate using REST API towards the back-end.
I asked this question before but it was unanswered for a week or so I think so I decided to ask again but with a different formula.
I have a JFX desktop app. one of the features of one of the modules contains a video upload to the server. I searched this around a lot but the solutions I found are in two categories
using servlet / jsp on the server and service in the desktop app
copying the file locally (not what I want)
now I am ok with havign a service doing it the upload that's what I expect but I dont see the need of having a deployment on the server plus I already have a webapp. Is it possible to just have a webservice in the server and call it in the desktop app code? I haven't found anything on this.
Yes, it's possible and preferable choice.
The potential solution I see would be:
deploy a file REST service on your File server where the videos would be held.
Example Rest service in Java: https://github.com/polopolyps/fileserver
Then in your java FX application you simply send user file (a video) using REST lib, see: http://square.github.io/retrofit/
and Voila you have your functionality.
I am using DynamicReports which uses Jasper Reports in a web application I am making. I got it to work and all seemed good until I noticed that when I closed the Jasper Viewer it stopped my tomcat server. Upon further investigation I found out that the viewer (Java Desktop App) is just showing on my machine because it's also the server machine and doing it on a remote client, the pdf viewer is still showing on my server machine.
Is there a good way to get jasper reports to show on the client computer with a web app?
Or is there a good alternative framework to generate reports and either embed them in JSP or download to the clients machine?
May be it's a bit late to answer the question. But may be the others need help to.
So, I used DynamicReports in my projects with java and jsf. What you need to do is, convert the report object into PDF, Excel or HTML format and display it in webbrowser with url (PDF and HTML), or download it for Excel format. So, the DynamicReports will not open the JasperViewer (don't use report.show() -> it will open JasperViewer in local machine).
OR alternative what you can also do, create desktop application to receive jasper report object through websocket communication and print direct to default printer.
If there are others ways, may be someone can share it.
Unfortunately, DynamicReports project is discountinued or down somehow. May be it's time to find an other alternative, because there is no further development. The reachable site https://github.com/dynamicreports/dynamicreports and https://dynamicreports.lbayer.com/
I hope it can help.
I am a C# developer who recently decided to venture into the mobile dev world specifically android dev using java. It has been a smooth ride until now. While I'm usually able to follow the tutorials on the android developers site and other sites easily, uploading an image/video to the app engine blobstore or cloud storage seems to be a bit over my head. I cant seem to wrap my head around the process.
I have already done the necessary steps to get my app running on app engine. I am able to register devices and save basic entities to the cloud but I cant seem to get any of the tutorials to work form me.
Basically my app allows users to take images or videos and then have them posted to my back end as part of a file sharing type of game.
I am not asking for someone to give me code that can accomplish this, instead pointing me to a very thorough tutorial would be great!
1.I need understand the role of a servlet (most examples use this for uploading to blobstore)
2.Where should the servlet reside?
3.Is there another way to do this without using a .jsp page for the file uploading ?
4. I have set up the app engine back end for my project including endpoints. Is there a way to send the images/video that way to the server and still be able to retrieve a serving url to fetch the image/video later?
I have been stuck on this for a week now and I'm getting quite discouraged as I cannot seem to adapt any of the tutorials that I have read to suite my needs. There are a few dark spots in my mind where the entire process is concerned. Since I am not familiar with java, servlets etc I'm stumbling in the dark and I just need a lamp to light my path. I think i'm just a step or two away.
BTW I have looked at these questions and tried the code suggested to no avail before deciding to post my own.
Upload to Appengine Blobstore in Android
BlobStore vs Cloud Storage for storing user uploaded images
Upload image from Android to Google Cloud Storage or Google App Engine Blobstore
Please help!
NOTE: I don't have an interface where the user gets to choose the image/video as it is to be taken directly from the camera and sent to the server(not sure that makes a difference).
You need to do a lot more reading. First understand servlets in general. Then learn how to use the blobstore or cloud storage api. Then read how to post directly to blobstore (not to the servlet) with a post-save servlet callback.
Welcome to the world of Java!
I'll try my best to explain the Servlets/JSPs part. I dont know a whole lot about Google app engine.
1) Servlets are nothing but Java objects but with more priveleges. Servlets know how to handle a web request! There are many things that come to mind when we talk about web request processing:
who maps the URL to this servlet?
Who gives this servlet user request parameters?
How can I guarantee only authorized users can access this servlet?
list goes on......
Answer to all above questions is a web container. And in the world of Java only one web container rules (others might differ): Apache Tomcat.
In short, servlets are Java objects created for you by Tomcat.
Where should the servlet reside?
They reside in Tomcat.
Is there another way to do this without using a .jsp page for the file
uploading ?
You dont need a JSP to send requests to a servlet. You can use jquery, python or anything else. As long as its a valid web request.
I have set up the app engine back end for my project including
endpoints. Is there a way to send the images/video that way to the
server and still be able to retrieve a serving url to fetch the
image/video later?
See the tutorial here. Especially 'Implementing Tweet My Picture' section.
Google app engine has Java API (along with python) and the best way to submit web request to that API using Java is servlets. That's why many example are in servlets. I think.
Here's what i would do if I were you:
Setup tomcat. There are many options. So reply if you are not sure.
Deploy your handler servlet that'll use Google app engine Java API.
Send your image files to blobstore (not the servlet). See the tutorial. App engine will forward blob related information to the handler servlet you created in step 2.
Use Blobstoreservice in that servlet so that users can access that uploaded image.
Let us know if this helped.
I am developing a new report engine for my company, our main web application is writing by PHP 5 and running on an Apache server. The new report server which I designed to use Apache FOP 1.0 ruing on Tomcat7,so far I created My own XSLT stylesheets and I can manage to generate a PDF report from the URL and let it display in my web browser.My goal on this project is to generate dynamic report from xml file which export from the PHP application.
Could anyone explain to me the logic behind How I can give those two talk to each others. I understand I could POST the XML and XSLT as string to the report server and POST it back the result I want(like PDF).
I know this will need Java involved,and as a PHP dev. I really don't have much background about Java,if you could show me some examples or links, it would be much appreciate.
I am using Saxon-B with Fop 1.0 on Tomcat 7 for the report server.
if you need more info from me,please also leave a comment. I will add it soon.
Thanks
There are two things your going to need to study.
http://www.w3schools.com/php/php_ajax_intro.asp This is a tutorial on using the XHR object from php. You should go through that. Also, if you aren't familiar with the XHR object, I would read this as well: http://www.w3schools.com/XML/xml_http.asp
You're going to have to create a servlet capable of responding to these requests. There are various tutorials on how to create a servlet.
Here is a link to a youtube video I fall back on when I forget how to do servlets: http://www.youtube.com/watch?v=EOkN5IPoJVs
In the video, he just uses straight up javascript; so you're php code is going to be doing what the javascript did in the video (item 1 on my list).
The video uses an older version of eclipse (I think ganymede), but it is pretty close to the same process in the newest version of eclipse.
Just to be blunt, this isn't something you're going to be able to figure out and make work properly. You've probably got at least a day to a weeks worth of learning here depending on your experience and aptitude; and this will only get you something basic. The servlet you make won't be secure, it won't have user authentication...my point is don't take anything for granted.