Running other programs from Java

Question

I need to run a couple of other programs from my own Java program, basically I need to run these command line statements.

svn log --xml -v > svn.log
         


        

Answer 1

The redirection > (like the pipe |) is a shell construct and only works when you execute stuff via /bin/sh (or equivalent). So the above isn't really going to work. You could execute

/bin/sh -c "svn log --xml -v > svn.log"

and read svn.log.

Alternatively, you can read the output from the process execution and dump that to a file (if you need to dump it to a file, or just consume it directly as you read it). If you choose this route and consume stdout/stderr separately, note that when you consume the output (stdout), you need to consume stderr as well, and concurrently, otherwise buffers will block (and your spawned process) waiting for your process to consume this. See this answer for more details.