How to Execute Windows Commands Using Java - Change Network Settings

How to Execute Windows Commands Using Java - Change Network Settings

Runtime.getRuntime().exec("netsh");

See Runtime Javadoc.

EDIT: A later answer by leet suggests that this process is now deprecated. However, as per the comment by DJViking, this appears not to be the case: Java 8 documentation. The method is not deprecated.

Run cmd commands through Java

One way to run a process from a different directory to the working directory of your Java program is to change directory and then run the process in the same command line. You can do this by getting cmd.exe to run a command line such as cd some_directory && some_program.

The following example changes to a different directory and runs dir from there. Admittedly, I could just dir that directory without needing to cd to it, but this is only an example:

import java.io.*;

public class CmdTest {
    public static void main(String[] args) throws Exception {
        ProcessBuilder builder = new ProcessBuilder(
            "cmd.exe", "/c", "cd \"C:\\Program Files\\Microsoft SQL Server\" && dir");
        builder.redirectErrorStream(true);
        Process p = builder.start();
        BufferedReader r = new BufferedReader(new InputStreamReader(p.getInputStream()));
        String line;
        while (true) {
            line = r.readLine();
            if (line == null) { break; }
            System.out.println(line);
        }
    }
}

Note also that I'm using a ProcessBuilder to run the command. Amongst other things, this allows me to redirect the process's standard error into its standard output, by calling redirectErrorStream(true). Doing so gives me only one stream to read from.

This gives me the following output on my machine:

C:\Users\Luke\StackOverflow>java CmdTest
 Volume in drive C is Windows7
 Volume Serial Number is D8F0-C934

 Directory of C:\Program Files\Microsoft SQL Server

29/07/2011  11:03    <DIR>          .
29/07/2011  11:03    <DIR>          ..
21/01/2011  20:37    <DIR>          100
21/01/2011  20:35    <DIR>          80
21/01/2011  20:35    <DIR>          90
21/01/2011  20:39    <DIR>          MSSQL10_50.SQLEXPRESS
               0 File(s)              0 bytes
               6 Dir(s)  209,496,424,448 bytes free

How to run Windows commands in JAVA and return the result text as a string

You can use the following code for this

import java.io.*; 

    public class doscmd 
    { 
        public static void main(String args[]) 
        { 
            try 
            { 
                Process p=Runtime.getRuntime().exec("cmd /c dir"); 
                p.waitFor(); 
                BufferedReader reader=new BufferedReader(
                    new InputStreamReader(p.getInputStream())
                ); 
                String line; 
                while((line = reader.readLine()) != null) 
                { 
                    System.out.println(line);
                } 

            }
            catch(IOException e1) {e1.printStackTrace();} 
            catch(InterruptedException e2) {e2.printStackTrace();} 

            System.out.println("Done"); 
        } 
    }

Running windows command line from Java

Take a look at OCR.java file of VietOCR, which uses ProcessBuilder to invoke Tesseract executable.

How to execute cmd commands via Java

The code you posted starts three different processes each with it's own command. To open a command prompt and then run a command try the following (never tried it myself):

try {
    // Execute command
    String command = "cmd /c start cmd.exe";
    Process child = Runtime.getRuntime().exec(command);

    // Get output stream to write from it
    OutputStream out = child.getOutputStream();

    out.write("cd C:/ /r/n".getBytes());
    out.flush();
    out.write("dir /r/n".getBytes());
    out.close();
} catch (IOException e) {
}

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