java - how reflect a long running workflow process in GUI? - java

I have a workflow of functions that eventually lead to a deployment of something.
the steps are as followed:
run a python script the produces some output.
run a bash script that copies this output to a given location
run a bash script (depending on the output of 1,2) that runs a java program (running make take few hours)
run another bash script on this output - final step
i want to be able to initiate this workflow from a GUI giving a set of parameters.
Then, I want to be able to get status reports of each step - so that the running user will know which step is currently running.
The main issue here is that each of the steps may take long time to finish.
My experience with developing GUI in java is limited.
Any advice on the direction I should go to?

If you really want to write this in Java, then you should try to find a good wizard library. See this question for some details.
Then, if at all possible that your scripts provide some feedback like the percentage of the operation completed then you could have a JProgressBar for each step independently and an overall one to show the user an idea of how much is done at any moment.

Related

Call a dockerized python script from another dockerized java application?

I need to create a Java application which sends some input parameters to a python script and sends some output back to my java application.
I cannot run the script in my java code using jython Or similar things as the python scripts are build on demand and I may need to add new scripts every now and then. So this should not impact my java app.
My java application will be running on a container and based on a few condition check it might have to select 1 of the py scripts from suppose 100 scripts and run it. And again the condition later on may change and a different script has to run at that time
I went through many websites and tutorials on the net but did not find anything relevant.
Has someone tried anything similar?

JavaFX show looping Python print output

I built a GUI in JavaFX with FXML for running a bunch of different Python scripts. The Python scripts continuously collect data from a device and print it to the console as it's collected in a loop at anywhere from around 10 to 70 Hz depending on which script was being run, and they don't stop on their own.
I want the end-user to be able to click a button on my GUI which launches the scripts and lets them see the output. Currently, the best I have done was using Runtime.exec() with the command "cmd /c start cmd /k python some_script.py" which opens the windows command prompt, runs python some_script.py in it, and keeps the command prompt open so that you can see the output. The problem with this is that it only works on Windows (my OS) but I need to have universal OS support and that it relies on Java starting an external program which I hear is not very elegant.
I then tried to remedy this by executing the python some_script.py command in Java, capturing the process output with BufferedReader, creating a new JavaFX scene with just a TextArea in an AnchorPane to be a psuedo-Java-console and then calling .setText() on that TextArea to put the script output in it.
This kinda worked, but I ran into many problems in that the writing to the JavaFX console would jump in big chunks of several dozens of lines instead of writing to it line by line as the Python code was making Print() calls. Also, I got a bunch of NullPointerException and ArrayIndexOutOfBoundsException somewhat randomly in that Java would write a couple of hundred lines correctly but then throw those errors and freeze the program. I'm pretty sure both of these issues were due to having so much data at such high data rates which overflowed the BufferedReader buffer and/or the TextArea.setText() cache or something similar.
What I want to know is what approach I should take at this. I cannot migrate the Python code to Java since it relies on someone else's Python library to collect its data. Should I try to keep with the pseudo-Java-console idea and see if I can make that work? Should I go back to opening a command prompt window from Java and running the Python scripts and then add support for doing the same with Terminal in Mac and Linux? Is there a better approach I haven't thought of? Is the idea of having Java code call Python code and handle its output just disgusting and a horrible idea?
Please let me know if you would like to see any code (there is quite a lot) or if I can clarify anything, and I will try my best to respond quickly. Thank you!
My solution was to still call the Python code from the Java Processbuilder, but use the -u option like python -u scriptname.py to specify unbuffered Python output.

Java program running in background

I have a simple java program which is just a single piece of code that reads from a database and modifies the contents of the database based on certain conditions. Now, what I want is that this program should start automatically at the startup and silently run in the background unless someone kills it from the task manager.
I have never done something like this before and don't know exactly how to go about it. Can someone help me out as to how this can be done?
Thank you..
Follow the these steps to do the job :(Assuming you are using windows and jre is installed )
First compile your java program and place the class file at one location.
Now create a bat file and place java LOCATION TO THAT CLASS FILE/MyProgram in that.
Put your bat file in start up programs
Restart the system, you will get your program running in back ground..!
Hope this will help you.
There are two problems here
How to add this program to the startup
Windows - Run Java application at Windows startup
Linux - Linux start-up script for java application
Run the program as a daemon (background process)
Simplest way to do is using a while loop and sleep for required time interval in the while loop. Then perform the database
operation.
Also for windows, you can check this JSL
http://www.roeschter.com/
Thanks.
first create you jar bash and then add it to you crontab task list.

Using a Java program I made on a Web Server

I created a small application that, when run, creates or updates some tables in a database by extracting data from some PDF files. Everything works fine in this desktop application, but the next step for me would be to make it possible for an administrator on a website to upload a PDF file and my Java program would then run and update the tables accordingly.
The problem is I have no idea where to start with this (the site isn't done yet, but I'm running some tests and it is going to be coded in PHP). I'd like to know what kind of technologies I need to let the server run the program and update everything as it would in the offline version. Sometimes it takes a while to update everything, so ideally, the user uploading the PDF could continue browsing other pages while the server does its job. (I'll probably implement something that when the server is done processing the file, it says if the program ended successfully or not in a log file)
Can someone tell me what terms to search for on Google or give me some pointers? I haven't chosen where my website is going to be hosted either, so if someone could tell me what to look for to know if they support running applications like this, I'd really appreciate it as well!
This could also apply to other programming languages as I know a bit of Python and C++ as well, so in the future I might have some applications in those languages I'll want to use on the web.
If I'm not approaching this the right way, I'm open to other suggestions, but the best solution would be to keep my Java program intact as I know it works exactly like I want it to and I'd rather not have to start it all over again.
If your host is *NIX based you can use crontab (Automatic Task Scheduler) to run your program at set intervals. Make it check if a "new" PDF exists, and run the program if there is. There may be a way to use Windows Task Scheduler type programs to do it on Windows. This is probably the easiest way.
Alternately you can use You can use shell_exec() in your php to execute a command on your *NIX system directly to run your java program.

schedule java program

I want to run my java program in regular interval , lets say, in every 3 hours. I am thinking to write a .bat file and put command to call java class. But what is the best way to run .bat regularly in windows xp. Thanks in advance. I dont want to use third party tool.
Windows scheduled tasks are built for exactly that purpose.
You can run things on multiple schedules (so you can get your every-three-hour behaviour) and you can get your code to run whether or not logged in.
The multiple scheduling is a bit tricky. You basically set it up as a daily task to start with but, near the end, it will ask you if you want to do advanced features.
Select yes then you can set up multiple schedules at that point.
If you want a pure Java Based solution you can try QUARTZ SCHEDULER. But as paxdiablo already mentioned, Windows Task Scheduler will do that as well.

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