As a command it runs fine from cmd prompt but not from java code

The code given below actually tries running a command. This c开发者_C百科ommand when run from command prompt, produces the necessary output. But when i try to run the application from java code, it keeps on running and doesn't produce any output file.

String arg[]={"C:\\app1.exe", "C:\\app2.exe", "c:\\app3.exe"};
String pwd[]={"123","-x","-sf"};
String outputfile="c:\\output.xml"
String command=arg[0]+pwd[0]+arg[1]+pwd[1]+arg[2]+pwd[2]+output;
Process pr=rt.exec(command);

String command=arg[0]+pwd[0]+arg[1]+pwd[1]+arg[2]+pwd[3]+output;

At least you are missing the whitespace between the arguments!

You should not concatenate all arguments to one string. Instead, pass them as separate arguments to

Process exec(java.lang.String[])

I think you made mistake in generating command.

It would be

C:\\app1.exe123C:\\app2.exe-xc:\\app3.exe-sfc:\\output.xml 

Make sure the space

And use this exec(String[]

My guess is that you haven't tried this in a debugger or printed what it is trying to run.

My guess is that when you make this compile, you don't have a command called.

C:\app1.exe123C:\app2.exe-xc:\app3.exe-sfc:\output.xml

You cannot have more than one : in the path.

You concatenate all commands and args, but you never insert spaces between the commands and args. So your command looks like this: "C:\app1.exe123C:\app2.exe-xc:\app3.exe-sfc:\output.xml" And also pwd[3] doesn't exist. You have an array with 3 elements, so the highest element would be pwd[2]. You should get and ArrayIndexOutOfBoundsException here (or is it just a copy-paste-mistake)?

Well there's a couple of things wrong with the code:

A space is needed between the commands and the arguments and pwd[3] is out of bounds. I ran this code and it works.

String arg[]={"C:\\app1.exe", "C:\\app2.exe", "c:\\app3.exe"};
String pwd[]={" 123"," -x"," -sf"};
String outputfile="c:\\output.xml";
String command=arg[0]+pwd[0]+arg[1]+pwd[1]+arg[2]+pwd[2]+outputfile;
try {
    Process pr=Runtime.getRuntime().exec(command);
} catch (IOException e) {
    e.printStackTrace();
}

Try:

String[] command = new String[] { arg[0], pwd[0], arg[1], pwd[1],
                                  arg[2], pwd[2], output };

This is assuming the command you wish to run is

C:\app1.exe 123 C:\app2.exe -x C:\app3.exe -sf c:\output.xml

If you really want to run three separate commands, you will have to run exec() more than once.

See the javadoc at http://download.oracle.com/javase/1.4.2/docs/api/java/lang/Runtime.html#exec(java.lang.String[]) for details.

EDIT: As another answerer has pointed out, there is no pwd[3]!

If your apps "app1", "app2" ... are run from the command prompt you need open that before. by launching cmd.exe first of all. And then as others suggested add space between app and arguments.

Try by pasting this in the Run/Search input field in windows:

cmd.exe /K C:\app1.exe 123 C:\app2.exe -x c:\app3.exe -sf c:\output.xml

cmd.exe /K keeps the propmt open after executing commands