Java reading standard output from an external program using inputstream

Question

I am trying to develop a class that reads the standard output of an external program(using an instance of Process, Runtime.getRuntime().exec(cmdLine, env, dir)). The program

Answer 1

For the benefit of others looking for solutions to this type of problem I just want to add that I had a very similar problem. But in my case the program was also waiting for a single line of input. So there need to be three threads involved to asynchronously handle all three channels.

Without writing to the output (i.e. the stdin of the executing program) caused the input (i.e. the output from the executing program) not to be captured completely. Writing to it hanged the process.

The solution was the three words by Jon Skeet: "and flush it". After adding the flush, no hang. Thanks!