How to Open the Command Prompt and Insert Commands Using Java

How to open the command prompt and insert commands using Java?

I know that people recommend staying away from rt.exec(String), but this works, and I don't know how to change it into the array version.

rt.exec("cmd.exe /c cd \""+new_dir+"\" & start cmd.exe /k \"java -flag -flag -cp terminal-based-program.jar\"");

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

Execute commands in cmd using Java

run

Runtime runtime = Runtime.getRuntime();      
try { 
    Process p = runtime.exec("start cmd.exe /k \"ghci.exe test.hs\""); 

} catch (IOException ex) {
 Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex); 
}

referens
http://ss64.com/nt/cmd.html

more info at How to open the command prompt and insert commands using Java?

Enter commands in the command prompt after it's been opened in Java?

The normal way to do this would be to put the commands in a script and execute the script.

You will need to consume the output of the child process (stdout and stderr) on separate threads, or your process will block.

how to prompt open file window from command prompt in java?

You can use a JFileChooser to be able to select a file from a dialog box.

Assuming you want to launch it outside a Java Swing application, you could proceed as next:

final JFileChooser fc = new JFileChooser();
// Open the dialog using null as parent component if you are outside a
// Java Swing application otherwise provide the parent component instead
int returnVal = fc.showOpenDialog(null);
if (returnVal == JFileChooser.APPROVE_OPTION) {
    // Retrieve the selected file
    File file = fc.getSelectedFile();
    try (FileInputStream fis = new FileInputStream(file)) {
        // Do something here
    }
}

More details about How to Use File Choosers

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