Process output from apache-commons exec

Question

I am at my wits end here. I\'m sure this is something simple and I most likely have huge holes in my understanding of java and streams. I think there are so many classes tha

Answer 1

Its a very old thread but I had to use Apache Commons Exec and had to solve the same problem. I trust with last version of Apache Commons Exec published in 2014, below solution works well both with and without watchdog;

class CollectingLogOutputStream implements ExecuteStreamHandler {
private final List lines = new LinkedList();
public void setProcessInputStream(OutputStream outputStream) throws IOException 
{
}
//important - read all output line by line to track errors
public void setProcessErrorStream(InputStream inputStream) throws IOException {
    InputStreamReader isr = new InputStreamReader(inputStream);
    BufferedReader br = new BufferedReader(isr);
    String line="";
    while( (line = br.readLine()) != null){
        //use lines whereever you want - for now just print on console
        System.out.println("error:"+line);
    }
}
//important - read all output line by line to track process output
public void setProcessOutputStream(InputStream inputStream) throws IOException 
{
    InputStreamReader isr = new InputStreamReader(inputStream);
    BufferedReader br = new BufferedReader(isr);
    String line="";
    while( (line = br.readLine()) != null){
        //use lines whereever you want - for now just print on console
        System.out.println("output:"+line);
    }
  }

public void start() throws IOException {
}

public void stop() throws IOException {
}
}

Above class can be set as StreamHandler for the executor as below;

//set newly created class stream handler for the executor
executor.setStreamHandler(new CollectingLogOutputStream());

Complete code is available here; https://github.com/raohammad/externalprocessfromjava