Execute command line command with arguments within Web Application

[Guillem Plasencia]

Hi,

I've been struggling through this for a while. I'm writing a Web application (run within Glassfish v3) where a Servlet will call a Class that will itself execute a command line program. The user provides an input file, which is saved in a temp folder (OK up to this point). Then,
i have to run this program passing it the absolute path to the input file, also the output of this program is another file which has to be set as a command-line argument (and other parameters). The program needs some libraries, so my app reads the needed environment variables (LD_LIBRARY_PATH in this case) from a configuration XML file, and sets it.

Here's the code:

try{
			logger.info("TB will now execute command line: |"+cline+"| with tempfolder:"+tempfolder);
			ProcessBuilder pb = new ProcessBuilder(cmds);
			Map<String, String> env = pb.environment();
                        // this retrieves environment variables set for this program
			env = VCCInitXMLParser.getProgram("Tauthor","1.0.3").getEnvVars();
			logger.info("TB loaded Environment Variables:"+env.toString());
 			String tempF = VCCInitXMLParser.getProgram("Tauthor","1.0.3").getTempFolder();
			logger.info("TB uses as Temporary Folder:"+tempF);
			pb.directory(new File(tempF));
			
			Process p = pb.start();
			BufferedReader breader = new BufferedReader(new InputStreamReader(p.getInputStream()));
                        BufferedReader ereader = new BufferedReader(new InputStreamReader(p.getErrorStream()));
			String line = breader.readLine();
                        String eline= ereader.readLine();
			logger.info("TB output first line:"+line);
                        logger.info("TauthorBroker error line:"+eline);
		}
		catch(Exception ex){
			logger.error("TB gave an Exception while trying to execute the commandline. Please re-submit task."+ex.getMessage()+" CAUSED BY:"+ex.getCause());
		}

As my log file reports, the (String-ified) program command line (with arguments) is:

/usr/software/program/tb.bin  --output=/usr/software/vcc_temp/tb/tb_output.sdf  -t 15 /usr/software/vcc_temp/input_comps.sdf

the temporary folder is:

/usr/software/vcc_temp/tb/ 

and the environment variables used is:

{LD_LIBRARY_PATH=/usr/software/program/:/lib} 

Unfortunately, i see no output at all in the expected temp folder, nor any Exception is raised/catched. The only clue i have about what might be wrong is the fact that Process API includes two methods: getInputStream(), getOutputStream() and getErrorStream().
The getErrorStream() gave me an error while loading shared libraries for one of the needed libraries,

-How do i set the environment variable that points to needed libraries for my command line program? (in command line it would be LD_LIBRARY_PATH, and this is just what i used but it does not recognize it properly)

-Do i have to use getInputStream() and getOutputStream() them to feed the input and read the output of the command line program? Isn't a bit misleading the fact that ProcessBuilder API includes a directory(File) to set the temporary folder, if the only way of setting program's input / reading program's output is through getInputStream and getOutputStream methods?

-I see that an OutputStream has methods to write in it, so i guess that should be my program's input, and the InputStream then would be my program's output, am i right?

Thank you very much,

Guillem