I have an experience of using shell script to ftp some file. And some files could just missed. For example for I have 100000 files to be ftp, there might be 1 or 2 files haven't been ftp and there is no obvious error.
The shell didn't stop when one of the files failed to be ftp, although we don't want the script to stop due to only 1 missing file, we still want it to have some feedback to know there is a problem.
Would it be better if we use java to ftp?
You should probably not use ftp at all -- but rather consider something like rsync which can restart failed transfers and only transfer the files which has been updated since last.
The fact that you are asking if java is better makes me think you are more proficient in java. It's probably best to use whatever language you are more comfortable with.
Unless it's perl ;) j/k
Related
I need to execute a java simulation program for a very long time, many hours or maybe days, and i wish i could do it on a server.
I've been heard about Cloud Computing, and i'm searching a free platform, or a very cheap one.
For example, i found Oracle Cloud, but i am open to any type of solution.
On the link there are several points to follow to deploy an application, it seems a bit complicated and you also have to install Maven.
Do you think there is a simpler solution, or that this one could be my best try?
I mean, my program consists on a few .class files, i wish i could edit/compile/run the main class very easily, like with a kind of shell or cmd.
Unfortunately, i know very little about web programming, so i don't know even if this would be possible.
However, assuming i can launch my program, and log in after a very long time, will i be able to read the results?
Or is it possible to write a text file to read the results later?
i wish i could do it on a server. I've been heard about Cloud Computing
A possible solution is using AWS Lambda. You only provide your Java code in a ZIP file and it will run in a "server-less" environment. What this means is that you don't have to setup a server yourself instead AWS will manage everything for you.
i'm searching a free platform, or a very cheap one.
It's not for free, but it's pretty cheap though: https://aws.amazon.com/lambda/pricing/
However, assuming i can launch my program, and log in after a very long time, will i be able to read the results? Or is it possible to write a text file to read the results later?
I would not recommend writing it to a text file, instead look at solutions such as S3 Buckets or Elasticsearch with Kibana
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.
I'm trying to find a way to duplicate a series of files/folders from one section on a server, to a new directory on the same server. I looked into doing this with FTP, but it seems to be strictly for transfer and not so much changing files on the server itself. As such, I've been looking into SSH and wondering if it might be possible that way. Is it possible? If not, is there another way, or perhaps and easier way to do this? Any help would be much appreciated thanks!
I'm not sure if this is the best way, but, if you have SSH access to the server, you can SSH in and use the system's native copy command. I would recommend you use the Jsch library to SSH into the box and then just call the appropriate command (cp or copy).
Jsch supplies no documentation, but they include tons of example code. You can follow the Exec.java file to show you how to execute commands on the remote server. Also, fyi, they use tons of swing code in their examples. You can easily remove all of that if you don't want swing username/password prompts.
Yeah, both FTP and SFTP (which is the file transfer mode of SSH) are mainly for transferring files between client and server. Additionally they also support some management tasks (like creating directories, setting modes, listing files, removing files/directories, even renaming files), but no copying of files without downloading and uploading again.
As Jon7 and Mark proposed, you can (per ssh) invoke the remote server's native copy command (copy or xcopy on Windows, cp on Unix-like systems) to do the job, assuming you have shell access (not only SFTP or some forced command).
If using JSch, an exec channel would be the thing to use here.
I'm trying to create a web application which will get input from system.
What this application should do is to listen what happens when some shell scripts are executing and reporting the status trough web.
An example :
I'm copying thousands of records with shell script, and while this is still executing I'd like pass the current status of the script to the web interface. From shell script side I could echo something like "The files are being copied please wait for it to finnish".
Using which programming language from shell side would be the easiest way to pass this to the web interface? I intended to use JSP/JAVA for web.
Is this even the right way to think about this? Every suggestion is welcome
EDIT
Would something like http://nodejs.org/ be useful for this?
I'd use a named pipe (FIFO) instead. You simply write your output to the pipe and let the application read it. I'm not sure if there is any other way to get a more live system than this.
I'd recommend Perl as the back-end.
EDIT:
named pipes are a special type of files on UNIX. The abbreviation FIFO stands for "First In First Out". On LINUX Journal you can find an interesting read about named pipes.
Perl is a very powerful scripting language with many ready-to-use modules which you can find on http://cpan.org. You can find some answers here on SO about how/where to start learning Perl.
The Web part of your application can easily read a file or a database, so you just need to make sure that your shell scripts are outputting something for your Java code to update.
For example, if you run your shell script like this
./myscript.sh > mylog.log
Then in your Java code (note that you should not have logic in your JSP), you can read in the file to determine the status of the update, and output the result to your JSP.
It would be better to read the data in from a database, but that would involve you changing your shell script to output the data to a database.
You could put shell script output to some storage on server. And use AJAX on the web page to poll the server and get updates from that storage to the page.
If you will decide to use JSF for web page creation I can recommend "a4j:poll" component from ajax2jsf library. It is very simple and straightforward. Very easy way to poll server from the web page.
Writing to log file would be the simplest solution. And in programming, simple often means good.
If you really need very fast/realtime system, you should probably make these logs a database.
As for language, use what you like best. They all do support SQLite, including bash.
If I understand your question correctly you want to display a web page on a client machine that reports the status of a long running task on a server machine. If that is the case then you need to focus on something called AJAX IMO.
For what it is worth the simplest and easiest to understand implementation of AJAX that I know of is Apache Wicket.
I need to create an application "dll, script or exe" which when the user upload on a folder on his server using his ftp, it will automatically run on the current folder and do some image manipulations in the folder images,
My Question is how to make something like this, which the user will not need to configure anything on his server, all what he want is upload in the right folder, and it will run automatically and keep running
Is it possible? How do it? Which Language to use?
UPDATE: I am targeting shared hosting server, which the user have no way to configure his server OS, about the OS, lets start saying its just windows.
I know that "Not possible" may be the right answer, and also "its a virus" may be another answer, i just want to know if its possible or should i think in another new way.
Everything I have read in this question screams "security vulnerability exploit". Since it's one of the main things hosting companies are making sure doesn't happen, I would say your chances are very slim to have that work.
However, if it's a web server, with something like CGI or PHP enabled, you could leverage that by uploading a CGI or PHP script in a place it can be run, and then calling it through a browser, thus doing whatever file manipulations you need... Things like safe mode, reserved or virtual directories could get in the way, but I think there is a better chance of that working.
Hmmm... is this a Window's or Linux machine? If this were on Windows, I would say create a C# service that uses FileSystemWatcher to listen for changes to the FTP folder and do your processing. As a service, it has no user interface and can run automatically on bootup.
Yes, there is!
http://en.wikipedia.org/wiki/Self_(programming_language)
One way I can think of is to use C# directory monitor. So whenever it found out a file is created in the folder it opens it up, checks the file type and executes it if it is an executable. However, you do have to watch out for incomplete file uploads though.
which the user will not need to configure anything on his server
What's the rationale of this requirement?
What's wrong with doing an initial configuration?
What's the target server? Is it linux, window, both?
Please be more specific.