Calling external programs from Java?

Question

Hi All,
Is there a way of calling external applications from Java without using Runtime.exec(). That method seems quite messy when you are dealing with streaming data from an input file to an output file. Basically what I'm asking is there a way to run a command the same way you would type it in a command shell?
Thanks

Answer 1

LeWalrus wrote:
Ok, I've an external application that I want to be called inside a Java GUI. It has several input arguements, which the format looks something like:
programname inputfile > outputfile
Simple enough.
>
Works fine from a shell command line. From what I understand, this won't work using Runtime.exec() because that method will just start the application. Works fine from Runtime.exec(). Since you are'>' to write stdout to a file you need to us a shell to execute the command.
String[] command = {"sh", "-c","programname inputfile > outputfile"};
Process process = runtime.exec(command);
You need to read, digest and implement the recommendations given in http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html .
File input and output from the application has to be taken care of programatically (java.io stuff). Fine if you've only one input and output. But if you have several input files and hundreds of output files, where does this leave you. It would be much easier if you could pass a string command to the shell directly as if you typed it in the command line yoursel!