I have a Java application and now I want to make it an web app.
Now I think about how to make the architecture of this app.
In fact, I have many resources, matlab, exe files and XML files and a MySQL database.
so we will have a 3-tier architecture.
Client: Browser
Treatment: Java EE server (maybe Servlet and EJB container)
Data: matlab, exe files and XML files and a MySQL database
So, how can I create this application without having a problem even if we have several clients connected which sends many queries at the same time?
Knowing that the processing is calling an EXE and reading and writing XML files, and execute MATLAB.
More details
INPUT -RESSOURCE-> OUTPUT
image(query) -exe-> XML
XML -JDOM-> Java Objects (List)
Java Objects -JDOM-> n XML files
n XML files -JDOM-> txt files
txt files -matlab-> txt files
txt files -MYSQL-> java objects (List)
txt files --> Images (results)
This is pretty broad question. So I will keep my answer at a high level and we can dig deeper as you have more questions.
Initially this is how I would structure the application.
Pick a MVC framework. I would pick JSF2 but anything else is fine too. Your view and controller layer will be defined here.
Create 3 DAO classes at bare minimum - one for reading data from XML, one for reading data from mySql, and one for reading text files. To parse XML files you can use XPath and ofcourse SQLs to get data from the database.
Create a MDB to asynchronously kick off the EXE process via JMS.
Package the application as an EAR file.
Tools you can use:
Eclipse for IDE
JBoss-AS (or any other container that you have access to)
Some sort of build/packaging tool (ANT, Maven, etc)
I am not familiar with image manipulation so I can't comment on that part. However, I think you need to break down your design into various components first. That's why I started listing the ones that I could think of without enough details. So image query will be one of the components. Try to create a black box diagram of the system with each major component in & out. After that start developing each of them and then I bet a lot more folks here can help you with more specific questions. Does this make sense?
Related
I am currently developing a web application for a local company using Java, Spring Framework and MySQL no ORM. This is the first time I have dealt with uploading files.
My situation is that part of the system allows an admin user to upload images for store items.
currently all my resources such as images are organised and located like such: (located in the unpacked .war at the ROOT of my tomcat server)
/resources/img/items/
/resources/img/items/thumbnails
However I have come to the realisation that when the web app is deployed and a user uploads an image, it will be stored in the above locations. Therefore when I redeploy, the uploaded images will not be present.
My question, is there a better location to store these images? Or am I missing something. I have been researching for the past couple of hours and seem to have not gotten far. I'd be very thankful to anyone who could offer some knowledge. Thanks in advance.
There are many options where to store files.
MySQL: Store them in your MySQL database using the BLOB datatype. The advantage is that you have all your persistent data in a single location which is handy when doing backups. On the other hand, image data may bloat your database quickly.
In the file system: Store them in the file system, e.g. in /var/yourapp/uploaded-images. You need to tell your application about where to find that directory. There are many ways to do this:
create a configuration table in your MYSQL and put the folder there
let your web container/server provide that variable
via JNDI service
...
Make sure you have a rescue plan when that disk crashes with tons of data ^^
Separate Database
Since image data may bloat your database quickly, you may want to use another database for your images. In many architectures binary data are separated from the "real" business data.
I guess these are the typical solutions to your problem. However, there is no standard recommendation what to choose for it depends on facts you didn't provide, or cannot provide at the moment:
Are the images business-critical (technical drawings)
Size of the images (8kB JPEG vs. 200 MB raw image)
What are the demands of your users and who are they (SaaS vs small intranet application)
... many more ;)
Whatever you choose, it is better than storing files in the exploded war :)
I'm using a java framework, Tapestry5. I have millions of pages and I'd like to generate my sitemaps with a nightly cron job rather than dynamically generate them on the fly. The problem I'm facing is I don't seem to know how to place the xml sitemaps dynamically in a directory that can be read publicly. Currently I have a manually written xml sitemap that points to dynamically written ones. The manually written sitemap is placed in the Web Pages / webapp directory along side the robots.txt file. How do I place a file there with java?
It's generally a bad idea to write to areas within your WAR directory. Fortunately, all the popular web and app servers (except perhaps some cloud hosting environments like Google App Engine) have the ability to configure an arbitrary directory on the file system as the path corresponding to particular URL patterns. This gives you the freedom to put the sitemap files anywhere you want.
I am trying to create a java standalone program and was wondering if there is a way to have some sort of data storage within my jar?
You see, my initial idea was to use xml files within the jar for reading and writing stuff in. I had no problem reading stuff from the xml files but I was told you cant really edit/create new files within a jar.
I want it so when i send the executable jar to my friend, initial data I have put in will be in it already and then they can just add to or change the data. I find it pretty tricky as it has to be a form of data storage without the internet access or any need for my friend to install anything more.
I decided to go for sqlite in the end. It works exactly how i want it to work. I might look into javaDB in the future as it seems to have better SQL language support sqlite.org/cvstrac/wiki?p=SqliteVersusDerby
As far as I know, JAR files are read-only, which cannot be rewritten to.
My suggestion is to use MS Access database as your JAR's data keeper.
As it is portable, the only weakness is that you have to bring both of your JAR and MDB files together (or put them in 1 folder).
I've searched and searched, coming across questions that address parts of the problem, but nothing comprehensive. I'm using GWT and eclipse to develop a website that uses highcharts to make some fancy plots.
The idea is that the user will be able to select one of their local data files of type csv and upon selection of the file, the plot will be rendered using their data and our fancy algorithms.
We don't want to send enormous amounts of data to the server as this will become costly and time consuming for the user. Is there a way to process or at least pre-process the user's data using Java code to be implemented in a GWT-eclipse project?
Any help is greatly appreciated!
This is a duplicate of GWT Toolkit: preprocessing files on client side
One of the answers points to these links:
http://code.google.com/p/gwt-nes-port/wiki/FileAPI - GWT wrapper for HTML5 File API
http://www.html5rocks.com/en/tutorials/file/dndfiles/ - HTML5 FileAPI
But, alas, the FileAPI is pretty new: http://caniuse.com/fileapi
The other alternative you have, to avoid server, is a text area to paste the CSV file into, then read that using GWT. This is a common trick and I think you can even copy+paste from certain spreadsheet programs this way.
You cannot do it in a universal way in GWT in all browsers currently. GWT translates to javascript and it does not have the required privileges to process client side the files.
For more detailed answer you can reference - How to retrieve file from GWT FileUpload component?
I have developed a command-line (read: no GUI) Java application which crunches through numbers based on a given dataset and a series of parameters; and spits out a series of HTML files as resultant reports. These reports hold a large amount of data in tables, so in order to give the users a easy and quick overview of the results, I utilized the JUNG2 library and created a nice graph.
Here's where it gets interesting; since I would like the graph to be interactive it should be deployed after the application has run and files are generated, whenever the user wants to view the reports. I decided to go with an applet based deployment, however I am not too happy with the current setup due to the following reasons:
I want to make the software as simple to use as possible (my users won't be tech-savvy, and even tech-intimidated in most cases). I would really like to distribute one JAR only, which forced me to put the applet with everything else it needs in a package in the same JAR as the main application.
The applet and the main application need to communicate the results, so I create a xML-based report which is used to hold information. As long as the files are on a local machine and are not moved around it all works fine. Unfortunately I also need the files to be moved around. A user should be able to take the "results" folder to a USB stick, go anywhere plug the stick to another computer and be able to use the report as he/she likes.
For the time being the applets are implemented with the following html code:
<applet code="package.myapp.visualization.GraphApplet.class"
codebase="file:/home/user/myApp"
archive="myApp-0.2.6-r28.jar"
width="750" height="750">
<param name=input value="results/test_name/results.fxml">
</applet>
As you can see this applet will not work if the parent folder is moved to another location.
As far as I know I have a couple of alternatives:
a) Change codebase to point to an URL on our webserver where I could put the jar file. This however creates the problem with permissions, as the applet will not be able to read the results file. Alternative is to upload the results file to the server when the user wants to visualize the graph, although I am not sure if that's a good option due to server security and also if it could be made so that upload happens automatically without bothering the user.
b) I can use a relative path on the codebase attribute, but then the whole folder hierarchy needs to be intact upon copy. This could be a last resort, if I cant come up with a better way to do it.
c) change the deployment method (would like to avoid this alternative to not spend more time on the development phase)
Any ideas? Am I missing something? How could I tackle this problem?
Thanks,
I'm not sure I entirely understand your use-case, but from what I do understand, I would suggest this:
Dump the applet for an application launched using Java Web Start. Have the JNLP file declare a file association for the fxml file type. When the user double clicks an fxml file, it will be passed as an argument to the main(String[]) of the JWS application.
A sand-boxed JWS application can gain access to resources on the local file system using the JNLP API. Here is my demo. of the JNLP API file services.