how to launch and work within an external software using java

[qwertyuiop415263]

hello. I am new to java and using eclipse IDE. i have a software known as QEMU which work only on command line i.e no gui and we have to work in this software from command line

e.g i write this line "qemu-system-arm.exe -M realview-eb -kernel D:\test.out -serial file:test.out" on command line its works fine.

now i have to lanch this command using java.
here is my code


import java.util.*;
import java.io.*;
public class Command{


public static void main(String args[])
{
try {
String fileName = "C:\\Documents and Settings\\Ali\\Desktop\\qemu-0.13.0-arm-win32\\qemu-system-arm.exe";
String[] commands = {"cmd.exe","/c","start","-M -realview-eb-kernal",fileName};
Runtime rt = Runtime.getRuntime();
Process pr = rt.exec(fileName);


BufferedReader input = new BufferedReader(new InputStreamReader(pr.getInputStream()));

String line=null;
while((line=input.readLine()) != null) {
System.out.println(line);
}

int exitVal = pr.waitFor();
System.out.println("Exited with error code "+exitVal);

} catch(Exception e) {
System.out.println(e.toString());
e.printStackTrace();
}
}
}


but it didn't work

[Norm]

it didn't work

Was there anything written to the error stream?

What is the purpose of the commands String array?

[qwertyuiop415263]

sorry it should be

Process pr = rt.exec(commands);
there is no compile time error

[Norm]

Hard to debug code that is not what you are executing.

Was there anything written to the process's error stream?

[qwertyuiop415263]

i only want to know how to launch a software(no gui) on command line and how to work within that software? (using java).

only help me with these lines
how to use .exec command??

String fileName = "C:\\Documents and Settings\\Ali\\Desktop\\qemu-0.13.0-arm-win32\\qemu-system-arm.exe";
String[] commands = {"cmd.exe","/c","start","-M -realview-eb-kernal",fileName};
Runtime rt = Runtime.getRuntime();
Process pr = rt.exec(fileName);

[Junky]

Google "pitfalls of Runtime.exec". Your problem(s) may already be explained.

[qwertyuiop415263]

thankx for replying..
i have already search with this key word but didn't find any useful link. actullay online tutorials only teach how to lanch softwares using java but they dont give any information about how work in these software while residing in the commnd line.

any help will be appreciated

[Junky]

What do you mean by "work in these software"?

Are you saying that you want a Java app to launch another app such as Word and interact with it? Then I have to ask why? There is the Apache libraries that allow you to read/write Word docs, Excel spreadsheets but there is no need to actually launch Word or Excel.

[DarrylBurke]

When Runtime.exec() won't

db

[qwertyuiop415263]

YES exactly .
because the software i am using "QEMU" works only in command line. when i write qemu-system-arm.exe i enter in the qemu command line.

[Norm]

You are not responding to this question:
Was there anything written to the process's error stream?

Also what is commands used for in your code:

String[] commands = {"cmd.exe","/c","start","-M -realview-eb-kernal",fileName};
Runtime rt = Runtime.getRuntime();
Process pr = rt.exec(fileName);

[qwertyuiop415263]

there is no error written in the error stream.

it should be
Process pr = rt.exec(commands);
instead of
Process pr = rt.exec(fileName);

[Norm]

To make sure your code and classes are correct, try using another command.
Try using it several ways, including some that will cause the command to write to the error stream. This will validate that your code is working correctly.