Invoke external programs from Java

I am running a Java program which will be used to invoke other command line programs in Windows.
However, it seems Java has problem in checking the termination state of command line programs in Windows. In the example below, the pp.waitFor() will keep waiting even if the command completed execution. I try the same code below in Unix and it works without problem. Is there anyone has come across the same problem before ?
I am using JDK1.4.1.
try {
Process pp = null;
BufferedInputStream bi = null;
pp=Runtime.getRuntime().exec("dir");
bi = new BufferedInputStream(pp.getInputStream());
pp.waitFor();
int size=bi.available();
while (size>0) {
byte[] buf = new byte[size];
bi.read(buf);
System.out.println(new String(buf));
size=bi.available();
} catch (Exception e) {
System.out.println("Exceptions !!!");
System.out.println(e.getMessage());

I found this article rather helpful:
http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html

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Invoke External programs from inside App Server

hi,
How can I invoke an external program from a session bean (or from an MDB)?
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If so, are there any security considerations?
thanks,
Sundar

I found this article rather helpful:
http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html

Calling external programs from Java?

Hi All,
Is there a way of calling external applications from Java without using Runtime.exec(). That method seems quite messy when you are dealing with streaming data from an input file to an output file. Basically what I'm asking is there a way to run a command the same way you would type it in a command shell?
Thanks

LeWalrus wrote:
Ok, I've an external application that I want to be called inside a Java GUI. It has several input arguements, which the format looks something like:
programname inputfile > outputfile
Simple enough.
>
Works fine from a shell command line. From what I understand, this won't work using Runtime.exec() because that method will just start the application. Works fine from Runtime.exec(). Since you are'>' to write stdout to a file you need to us a shell to execute the command.
String[] command = {"sh", "-c","programname inputfile > outputfile"};
Process process = runtime.exec(command);
You need to read, digest and implement the recommendations given in http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html .
File input and output from the application has to be taken care of programatically (java.io stuff). Fine if you've only one input and output. But if you have several input files and hundreds of output files, where does this leave you. It would be much easier if you could pass a string command to the shell directly as if you typed it in the command line yoursel!

Invoking python program from java

I want to execute a parser program(which is in python) that parses log file from java interface.The design of Java user interface has to be such that the log file is obtained from the user into a text field.The file name has to be read from the text field and this has to be taken by the python log parser program.How can this be implemented?

You can invoke an external program using:
Runtime.getRuntime().exec("bla.exe");
See: http://java.sun.com/j2se/1.4.1/docs/api/

Starting a external program from java

hi iam trying to start MySQL server from java, the command in dos is as follows C:\mysql\bin\mysql -u username -p ,then the user hits return and the user is prompted to enter a password. i have got as far as entering the the C:\mysql\bin\mysql -u username -p but dont know how get the prompt back to the java program i would be greatfull if anyone could tell me where iam not doing,heres my code so far
try{
Runtime r=null;
r=r.getRuntime();
Process p=r.exec("C:/mysql/bin/mysql -u mark_r -p");
p.waitFor();}
catch(Exception ex){System.out.print("Error");}}

You should try using the getOutputStream() and getInputStream() methods for the Process object. Each returns either an inputStream or OutputStream object.
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Pocket PC -Problem executing external program from java

Hi,
I'm developing an application on Dell Axim x51 PDA. I am using mysaifu jvm. The application needs to execute an external program (.exe) for which I'm using the Runtime class.
I get java.io.IOException: The system cannot find the file specified.
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here's the part of code :
Runtime rt = Runtime.getRuntime ();
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You have acces to "java.lang.Runtime currentRuntime.exec()" method ? in my case NetBeans IDE dont give me for my compilation with :
          microedition.configuration     CLDC-1.1
          microedition.profiles     MIDP-2.0

Controlling external programs from Java

Hi,
I try to invoke an external command-line program in Windows 2000 fron Java. I do this by
Process proc = Runtime.getRuntime().exec(cmd);
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"cmd /c C:\\gnupg\\gpg --list-keys"
This works fine. But when I want to make a more advanced control, when gnupg waits for more than one input, and that input can't be put on the same line I get problems.
When running gpg --edit-key SomeKey on the command line I have to enter
trust - return - 5 - return - yes - return - quit
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this is how to do it! gotta listen to the output to prevent deadlock. you can pass in parameters o the initial call as well (a string array, where string[0] = command, string[...] = input argument) or write it to the output stream of the process.
hope this helps
public void run_command(String starting_command, String[] further_commands)
Process proc = Runtime.getRuntime().exec(starting_command);
Listener.make(proc.getInputStream());//these listen to the streams
Listener.make(proc.getErrorStream());//which prevents deadlock
PrintWriter writer = new PrintWriter(new OutputStreamWriter(proc.getOutputStream()));
for(int i = 0;i < further_commands.length;i++)
writer.println(further_commands);//you could put the extra stuff as the first string in this array
import java.io.*;
public class Listener extends Runnable
BufferedReader reader;
public static void make(InputStream in)
Listener l = new Listener(in);
Thread thread = new Thread(l);
thread.start();
public Listener(InputStream in)
reader = new BufferedReader(new InputStreamReader(in));
public void run()
String string;
while(true)
string = reader.readLine();
try
Thread.sleep(1000);
catch(Exception e)

Problems running external programs from java

Hello.
I wrote a pair of perl scripts and a GUI in java to run them. The first perl script just read the files in one directory makes some changes to the names of the files and then group all this files in a set of new directories. The other perl scripts takes all this new files and calls BLAST sequence alignment program and perform some alignments among these sequences. I tested this scripts and they work fine.
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Invoke /bin/sh -c and give it your program's full path with.
(To understand what I've written, maybe reading
http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps_p.html
http://mindprod.com/jgloss/exec.html
and
http://java.sun.com/j2se/1.4.2/docs/api/java/lang/Runtime.html
(especially the exec(String[] cmdarray) method)
might help)
-T-

Execute external program from java in the same virtual machine

hello,
I need some help. here is what i need: i'm developing a test tool and i need to execute the application to be tested from my test tool in the same virtual machine so that i can be able to connect to that application and catch events like clicking and so on.
problem is that i do not know how to launch the application i want to test in the same virtual machine as the test tool.
any help would be good,
thanks

problem is that i do not know how to launch the
application i want to test in the same virtual
machine as the test tool.Just invoke the main class of that application.
You probably don't want to hear this, but writing a test tool is not easy if you are going to try to catch events etc. It's probably a bit too hard for you if you don't know how to invoke an app within the same VM.
Kaj

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Hi NIlesh,
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Thanks and Regards,
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Hi,
I'm not able to invoke dos shell from java.
Can any one help me in this issue.
I'm providing the source code below:
try{
Runtime.getRuntime().exec("cmd.exe")
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Does it throw a different exception?
Or does it just do nothing at all?
It does nothing at all[/b
Is this a standalone Java app?
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I can probably get by with cgi on Apache's httpd server (or, I understand tomcat supports cgi, but I have yet to get that to work either), but whatever I do I need to be able to do it from within the button's event handler. And if I resort to cgi, I must be able to maintain session jumping from one server to the other and back.
So, then, how can I do this?
Thanks
Ted
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NB: In the following array_function_test.pl was placed in the same folder as the web application's jsp pages, (and I'd tried WEB-INF - with the same result), and I DID see the file in the application's war file.
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            java.lang.ProcessBuilder pn = new java.lang.ProcessBuilder("array_function_test.pl");
            //pn.directory(new java.io.File("K:\\work"));
            java.lang.Process pr = pn.start();
            java.io.BufferedInputStream bis = (java.io.BufferedInputStream)pr.getInputStream();
            String tmp = new String("");
            byte b[] = new byte[1000];
            int i = 0;
            while (i != -1) {
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                tmp += new String(b);
            getSelectionsDisplayTextArea().setText(getSelectionsDisplayTextArea().getText() + "\n\n" + tmp);
        } catch (java.io.IOException ex) {
            getSelectionsDisplayTextArea().setText(getSelectionsDisplayTextArea().getText() + "\n\n" + ex.getMessage());
        }

Hi Fonsi!
One way to execute an external program is to use the System Exec.vi. You find it in the functions pallet under Communication.
/Thomas

How can I run an external program from a PLSQL procedure?

Is there a package to run an external program from PLSQL? or is there another way to do that?
thanks.

here there is an example about how a PL/SQL procedure can
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http://download-east.oracle.com/docs/cd/A87860_01/doc/appdev.817/a76936/dbms_pi2.htm#1003384
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Java Stored Procedures Developer's Guide Contents / Search / Index / PDF
http://download-east.oracle.com/docs/cd/B10501_01/java.920/a96659.pdf
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How to execute external program in java?

My question is how to execute an external program in java.
I need to call a unix command in java.
Thanks.

it depends on what you are trying to do. Following are the two methods
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Invoking Microsoft Word from Java code

I want to invoke Microsoft word from Java code. How can i do this plz ............... Help

do something along these lines.... here is an example with notepad
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Invoke external programs from Java

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