how to execute command from textfile using runtime exec

[Jhovarie]

Hello im trying to execute a command from reading a text file. first my application read the content of textfile and the command from textfile will be executed using Runtime.getRuntime()
but it doest not work.

see my code.

public class Main_exec {

    public static void main(String[]args){
        try{ 
   //runtime test #1         
   // Runtime.getRuntime().exec("cmd /c start C:\\image.jpg"); // <- working  
      
    //runtime test #2
    //  String command = "cmd /c start C:\\image.jpg"; // <- working
    //  Runtime.getRuntime().exec(command); 
        
       //runtime test #3 <- not working    
      TextCommand fsd = new TextCommand();
       String readtextfile = fsd.ReadFile();
       
         System.out.println(readtextfile); 
         javax.swing.JOptionPane.showMessageDialog(null,readtextfile);
         Runtime.getRuntime().exec(readtextfile); //<--not working
        // Runtime.getRuntime().exec("".concat(readtextfile)); //<--not working
       
        }catch(Exception ex){
        }
    }
}

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;

class TextCommand {
    private static Reader rd;
    public static String ReadFile() throws IOException{
         File execute = new File("C:\\cmd.txt");
         rd = new FileReader(execute);
        String s = "";
      BufferedReader bfr = new BufferedReader(rd);
      String s2 = "";
       while((s = bfr.readLine())!=null){
          s2+=s;
          
      }
      rd.close();
      bfr.close();  
      System.out.println("from textCommand"+s2);
    return s2;
    }
}

text filename = "cmd.txt"
content = "del image.jpg"

thanks in advance

[JosAH]

Make the contents of that file:

cmd /c del image.jpg

The 'del' command is internal to your command processor cmd.exe

kind regards,

Jos

[Jhovarie]

cmd /c del image.jpg

working but if i tried a command with path like this

cmd /c del c:\image.jpg

or

cmd /c del c:\\image.jpg

nothings happen.

[Norm]

nothings happen.

Try reading the Process's error stream to see if there are any error messages

[JosAH]

nothings happen.

That is kind of vague; does the String come through when you read it from your file? Does the file exist before you execute that command? Can the process be started? As Norm already suggested: does the process complete with an error? Those are all things you have to check before you come here and complain that nothing happens.

kind regards,

Jos

[Jhovarie]

looks like my computer is infected by a virus no error message from my Process and no output ithink "cmd /c" is working

          Process pr = Runtime.getRuntime().exec(readtextfile); 
            BufferedReader bfr = new BufferedReader(new InputStreamReader(pr.getInputStream()));
		String s = "";
		while((s=bfr.readLine())!=null){
		System.out.println(s);
            }

[Norm]

To check your java code, try starting notepad.
To check the syntax of you command, try it in a command prompt window.

[Jhovarie]

i found the solution now. i just reformat my computer because it i infected by the virus. "cmd /c" is working.