Not able to call a bat file from JAVA

[Praveen Kumar Jayaram]

Hi

I am trying to call a .bat file from Java.
The .bat file works perfectly if I am running it manually.

Now I need it to be called from Java. But it shows a blank console window, without executing the .bat file (it is not able to load the .bat file).

Here is the code:

[B]cmdStr= new String[]{"cmd", "/C", "start","\""+SystemFilesDir.getAbsolutePath()+"\\Batch.bat"+"\""};
Process fortranExecutor = Runtime.getRuntime().exec(cmdStr);[/B]

Please suggest what is wrong in my code.
Thanks in advance

[Rob Spoor]

Try removing the quotes around your path. Although it is usually necessary if you type the command as one whole, this method should remove that need. Remember, you're not passing the file as an entire parameter, but the file wrapped in quotes.

Consider the following:

String s = ".";
File file = new File(s);
System.out.printf("%s, %s: %b%n", s, file.getAbsolutePath(), file.exists());
s = "\"" + file.getAbsolutePath() + "\"";
file = new File(s);
System.out.printf("%s, %s: %b%n", s, file.getAbsolutePath(), file.exists());

When run from D:, the results are as follows:

D:\>java Test
., D:\\.: true
"D:\\.", D:\\"D:\.": false

[Steve Fahlbusch]

If you are calling a bat file, the you should not be using Java......

You should rethink what you are doing...

While it can be done...

SHOULD IT???

[Joe Ess]

Originally posted by Steve Fahlbusch:
If you are calling a bat file, the you should not be using Java......

We know precious little about Praveen's situation to pass such a judgment. If he wants to invoke a batch file from java, let's help him. If he asks if it is a good idea or not and fills in details about what he's dealing with, then we can help him make an informed decision.

[Ernest Friedman-Hill]

You probably want to add

System.out.println(SystemFilesDir.getAbsolutePath()+"\\Batch.bat")

to see what it actually looks like. And it's entirely possible that those extra quotes are causing the problem; Windows CMD is really funny about quotes.

[William Brogden]

Read the JavaDocs on java.lang.Process

Note the critical point about consuming the standard out and standard err output streams. If you don't, it just sits there.

This has come up a LOT on this forum.

Bill

[Geo Joseph]

Also you need to read this article from JavaWorld

regards,

Geo

[G Estes]

Try this...then read through what is going on...should help...

   private void execCommand()
   {
      // gather the environment settings
      final Map<String, String> env = System.getenv();
 
      // I am using USERPROFILE, but can be whatever your pre-set is
      String filePath = env.get("USERPROFILE");
 
      try
      {
         // the directory where the batch file is located
         File fileDir = new File(filePath);
         // get the runtime object
         Runtime rt = Runtime.getRuntime();
         // execute the batch file found in a specific location
         rt.exec("run testfile.bat", null, fileDir);
      }
      catch(Exception e)
      {
         // if there is an error, it will show up here
         e.printStackTrace();
      }
   }
 

[ September 08, 2008: Message edited by: G Estes ]