Could someone help me with class Process getErrorStream() ??

Question

Hello
I want to execute process "/usr/bin/octave" .So I have to write to its input and read its output and error stream. I have written program and it works good until I need to read error stream of process. After I read the error stream of process i receive the IOException Broken pipe. It looks like after read the data from error stream process is closed so I coudn't write anything to the input stream (what i could do before reading from error stream). The errors I receive :
java.io.IOException: Broken pipe
at java.io.FileOutputStream.writeBytes(Native Method)
at java.io.FileOutputStream.write(Unknown Source)
at java.io.BufferedOutputStream.flushBuffer(Unknown Source)
at java.io.BufferedOutputStream.flush(Unknown Source)
at sun.nio.cs.StreamEncoder$CharsetSE.implFlush(Unknown Source)
at sun.nio.cs.StreamEncoder.flush(Unknown Source)
at java.io.OutputStreamWriter.flush(Unknown Source)
at java.io.BufferedWriter.flush(Unknown Source)
at wazna$3.run(octave.java:116)
at java.lang.Thread.run(Unknown Source)
And here is my code:
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
public class octave{
public static void main(String[] args) throws IOException, InterruptedException {
Runtime r = Runtime.getRuntime();
final Process p= r.exec("/usr/bin/octave");
System.out.print(">>");
InputStream iss = p.getInputStream();
BufferedReader br =
new BufferedReader(new InputStreamReader(iss));
try {
while (iss.available() == 0) { }
while (br.ready())
System.out.println(br.readLine());
} catch (IOException e) { e.printStackTrace();}
String s=null;
do
System.out.print(">>");
BufferedReader in = new BufferedReader(new
InputStreamReader(System.in));
s = in.readLine();
if (s.equalsIgnoreCase("exit"))
System.out.print(">>");
System.out.print("END");
else
Thread reading = new Thread(
new Runnable()
synchronized public void run()
InputStream iss = p.getInputStream();
BufferedReader br =
new BufferedReader(new InputStreamReader(iss));
try {
while (iss.available() == 0) { }
while (br.ready()) {
System.out.println(br.readLine());
} catch (Exception e) {e.printStackTrace();                                                                                                                                } }
Thread error = new Thread(
new Runnable()
synchronized public void run()
InputStream err=p.getErrorStream();
BufferedReader er =
new BufferedReader(new InputStreamReader(err));
try {
while (err.available() == 0) {
while (er.ready()) {
System.err.println(er.readLine());
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
final String g=s;
Thread writing = new Thread(
new Runnable()
synchronized public void run()
OutputStream oos = p.getOutputStream();
BufferedWriter bw =
new BufferedWriter(new OutputStreamWriter(oos));
try {
bw.flush();
bw.write(g);
bw.newLine();
bw.flush(); //LINE 116 where is an error
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
writing.start();
reading.start();
error.start();
while (!s.equalsIgnoreCase("exit"));
Message was edited by:
tazja
Message was edited by:
tazja

Answer 1

I know it's a bit late for this. But I hope it will help all the people who encountered this problem.
The only way to let octave work with streams is to use the --interactive switch (otherwise it will crash on the first error). Rembember that using this will need a different way to read data (BufferedReader won't work well).
Hope this helps anyone, I spent very much time figuring this.
Bye