asked on

How to run external program in java?

I try to run sqlldrin my java code. I wrote a small to test if exec is working. The code is as following:

try {
System.out.println("Starting");
Process p = Runtime.getRuntime().exec("ping 127.0.0.1");
p.waitFor();
if ( p.exitValue() ==0)
{
System.out.println("done");
}
}catch (IOException ioe){
System.out.println(ioe);
}catch (InterruptedException ie){
System.out.println(ie);
}

It doesn't work. It seems it will stop there forever.I run it on Windows 2000. Please help me figure out why?

Thanks.

ASKER CERTIFIED SOLUTION

JK2429

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kiranhk

Check out this link
http://www.idevelopment.info/data/Programming/java/PROGRAMMING_Java_Programming.shtml

in that check out Running External OS Commands

the following is the program from the site which u can use

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

/*
* Created on Oct 11, 2004
*
*/

public class TestCode {

public static void main(String[] args) {

String s = null;

try {

// run the Unix "ps -ef" command

Process p = Runtime.getRuntime().exec("ping localhost");

BufferedReader stdInput = new BufferedReader(new
InputStreamReader(p.getInputStream()));

BufferedReader stdError = new BufferedReader(new
InputStreamReader(p.getErrorStream()));

// read the output from the command

System.out.println("Here is the standard output of the command:\n");
while ((s = stdInput.readLine()) != null) {
System.out.println(s);
}

// read any errors from the attempted command

System.out.println("Here is the standard error of the command (if any):\n");
while ((s = stdError.readLine()) != null) {
System.out.println(s);
}

System.exit(0);

} catch (IOException e) {
System.out.println("[IOException]. Printing Stack Trace");
e.printStackTrace();
System.exit(-1);
}
}
}

GrandSchtroumpf

it works fine on my XP machine

GrandSchtroumpf

this is a version i found in my archives that echoes the output of the ping:

import java.io.*;

class ProcessReadOut {
public static void main(String[] args) {
try {
String command = "ping localhost";
Runtime rt = Runtime.getRuntime();
Process p = rt.exec(command);
InputStream in = p.getInputStream();
InputStreamReader inReader = new InputStreamReader(in);
BufferedReader bInReader = new BufferedReader(inReader);
String currRead;
while ((currRead = bInReader.readLine()) != null) {
System.out.println("from java -> " + currRead);
}
} catch (Exception e) {
e.printStackTrace();
}
}
}

Mick Barry

there's also an example of reading exec() output at:

http://www.objects.com.au/java/examples/util/ConsoleExec.do