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Trying to run java program for running windows command, but program is not working

I'm trying to run windows commands by using java code, but code is not working and giving exception error.
Following is the code
import java.io.*;
public class run_command
{
public static void main(String args[])
{
try
{
String command = "start firefox";
Process process = Runtime.getRuntime().exec(command);
}
catch(IOException e){ System.out.println(e); }
}
}
And following is the exception error
java.io.IOException: Cannot run program "start firefox": Create
Process error=2, The system cannot find the file specified.
This error is occurring for every windows commands. Please suggest some solution on this.
thanks.

You have to run program start with parameter firefox:
Process process = Runtime.getRuntime().exec("start", "firefox");
start is an executable, so is firefox, but there is no such executable named start firefox.

Java need process to return when finished

my problem would take 2 questions, but I'll keep it short. So I need to launch a bat file. Right now I do it like this:
public static void check() throws InterruptedException{
try {
Runtime.getRuntime().exec("cmd /c start build.bat");
Thread.sleep(3000);
} catch (IOException e) {
e.printStackTrace();
}
}
The bat file launches the java compiler to compile another java file and direct the error messages into a txt file. This is what the bat file looks like:
#echo off
javac -Xstdout error.txt MainApp.java
exit
Now the problem is, that I have to include a 3 second sleep, in order to be sure, that the error.txt has been created and filled with errors. This is very unsatisfying. I'd either need a return value from the bat file, so I the rest of the program waits, until it's done or a way to launch the java compiler out of the program and direct the error messages into a txt file.
Thanks everybody.

You can use Process#waitFor:
Causes the current thread to wait, if necessary, until the process
represented by this Process object has terminated
Process p = Runtime.getRuntime().exec("cmd /c start build.bat");
p.waitFor();

Running a command-line operation from within Java

I built a very simple program to test running a command line operation separate of Java. That is: later I want to be able to modify this code from using "move" to any other command I can enter into the command line (including calling other, non-Java, software).
I did search and read probably two dozen answers, but they all either suggested I was trying this correctly, were irrelevent to my simple test or proposed other solutions which did not work (like using the .exec(String[]) method instead of .exec(String) - same result!).
Here is my code:
import java.io.IOException;
public class RunCommand {
private static final String PATH_OUT = "C:\\Users\\me\\Desktop\\Temp\\out\\";
private static final String FILE = "sample.txt";
private static final String PATH_IN = "C:\\Users\\me\\Desktop\\Temp\\in\\";
public static void main(String[] args) {
try {
String command = "move "+PATH_IN+FILE+" "+PATH_OUT;
System.out.println("Command: "+command);
Runtime.getRuntime().exec(command);
} catch (IOException e) {
e.printStackTrace();
}
}
}
Here is what I see output when I run:
Command: move C:\Users\myingling\Desktop\CDS\Temp\in\sample.txt C:\Users\myingling\Desktop\CDS\Temp\out\
java.io.IOException: Cannot run program "move": CreateProcess error=2, The system cannot find the file specified
at java.lang.ProcessBuilder.start(Unknown Source)
at java.lang.Runtime.exec(Unknown Source)
at java.lang.Runtime.exec(Unknown Source)
at java.lang.Runtime.exec(Unknown Source)
at RunCommand.main(RunCommand.java:13)
Caused by: java.io.IOException: CreateProcess error=2, The system cannot find the file specified
at java.lang.ProcessImpl.create(Native Method)
at java.lang.ProcessImpl.<init>(Unknown Source)
at java.lang.ProcessImpl.start(Unknown Source)
... 5 more
Note that when I copy/paste the command into a command prompt window, the file moves successfully though.
What am I missing? All the other questions I've read seem to indicate this should work.
Thanks!
EDIT Works now, thanks for the help everyone! It's annoying that it's hidden the way "move" is a parameter of cmd.exe. I wish they had made it so if it worked when copy/pasted it worked when you called the .exec() method. Oh well.

The "move" command is part of the cmd.exe interpreter, and not a executable by itself.
This would work:
cmd.exe /c move file1 file2

Try this:
Runtime.getRuntime().exec("cmd.exe /c move "+PATH_IN+FILE+" "+PATH_OUT);

In Windows, unlike UNIX, move isn't a separate program. You need to involke the command processor CMD with move as an argument. Read the command line help on CMD, there's a flag you have to set.

move isn't actually a program, its a shell built-in command. Use something like:
String command = PATH_TO_SYSTEM32 + "\\cmd.exe /c move \""+PATH_IN+FILE+"\" \""+PATH_OUT + "\"";
Good practice is to always use absolute paths for external programs. (Well, good practice in this case would be to use Files.move or an equivalent instead of a platform dependent shell call)

Not able to execute an exe file from java using ProcessBuilder

I am making a project to run C, C++ and Java, from within Java code itself. It works absolutely fine for Java, and the problem is faced when compiling and executing C and C++ files.
I got my compilation right with this code and I can get the executable file generated in my specified path. But now when I run the executable binary from ProcessBuilder I get an error saying that 'file was not found'. Please see to the code and tell me what is going wrong and where??
public void processCode(String path,String lang)throws IOException
{
String cmd="",s=null,out=null,file="";
totalTime=0;
ProcessBuilder process=new ProcessBuilder();
process.directory(new File(path));
if(lang.equals("c")||lang.equals("cpp"))
{
cmd=threadNum+".exe";
process.command(cmd);
}
else if(lang.equals("java"))
{
cmd="java";
file="Main"+threadNum;
process.command(new String[]{cmd,file});
}
process.redirectInput(new File(PATH+"Input\\" + prob + ".txt"));
process.redirectOutput(new File(PATH+"Output.txt"));
Process p=process.start();
long start=System.currentTimeMillis();
while (true)
{
try{
if(p.exitValue()==0)
{
totalTime=(int)(System.currentTimeMillis()-start);
break;
}
}
catch (Exception e)
{
}
if(System.currentTimeMillis()-start>2000)
{
res=1;
p.destroy();
break;
}
}
if(res!=1)
{
compareFile();
}
}
The method is called from here
And the error generated is :
Exception in thread "main" java.io.IOException: Cannot run program "19.exe" (in directory "C:\wamp\www\usercodes\lokesh"): CreateProcess error=2, The system cannot find the file specified
at java.lang.ProcessBuilder.start(ProcessBuilder.java:1029)
at Contest.processCode(Main.java:202)
at Contest.compileCode(Main.java:180)
at Contest.makeFile(Main.java:157)
at Contest.main(Main.java:53)
at Main.main(Main.java:15)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
Caused by: java.io.IOException: CreateProcess error=2, The system cannot find the file specified
at java.lang.ProcessImpl.create(Native Method)
at java.lang.ProcessImpl.<init>(ProcessImpl.java:188)
at java.lang.ProcessImpl.start(ProcessImpl.java:132)
at java.lang.ProcessBuilder.start(ProcessBuilder.java:1021)
... 10 more

Setting the directory of a ProcessBuilder does not have any effect on where the system will look for the executable when it tries to start a process. It merely sets the current working directory of the newly-created process to this directory, should it be able to launch a process successfully. Your program 19.exe may well exist in C:\wamp\www\usercodes\lokesh, but unless this folder is on the PATH, the system will not be able to start your process.
Try running the process using the full path of the executable instead of just 19.exe.
It does have to be said that the error message is somewhat misleading. It says that it couldn't find your executable, and then it says 'in directory ...', which implies that that was where it was looking for it.

error calling c++ from java program

I want to call a c++ executable from a java program. But after I call it, nothing happens. Then after I close the program, there an error window appears, which says abnormal program termination.
The code looks like this :
try {
Runtime rt = Runtime.getRuntime();
Process p = rt.exec("discretize.exe");
} catch (Exception exc) {/*handle exception*/
exc.printStackTrace();
}
and the windows error that appears look like this :
http://dc532.4shared.com/img/8e2-xhaG/debug.PNG

Finally I found the answer.
The problem was the command prompt didn't show up. So after searching google, I found a tip that suggested I simply put:
cmd /c start
before the path of the file. So I changed my code to look like this:
Process myProcess = Runtime.getRuntime().exec("cmd /c start D:\A_TA\KODINGAN\TA\src\discretize.exe");
.. and voila, the command prompt shows!

I would try doing this below as found from this site: http://www.boards.ie/vbulletin/showthread.php?t=218960
Example:
Process myProcess = Runtime.getRuntime().exec("path to exe");