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Thread: check to see if a file exists using the current directory

  1. #1
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    Default check to see if a file exists using the current directory

    I have a program, that after the user puts in some information, they click a button to exectute the program. I want the code to check to see if a file exists before executing the program.
    I need my program to look in the same directotry that it is running from for a .lic file. Then if it does not exeist to alert the user that there is no license installed and to follow the readme instrucitons found in the running directory.

    Here is my coding for the button execution.
        private void btnRunRelapActionPerformed(java.awt.event.ActionEvent evt) {                                            
          String in = tfIntdta.getText();
          String rst = tfRstplt.getText();
          String out = tfOutdta.getText(); 
          String strip = tfStpdta.getText();
          String guistring = "-n gui";
          String wd = System.getProperty("user.dir");
          String osver = System.getProperty("os.name");
          String exec = "";
            if (osver.contains("Mac OS X")){
               exec = "/Users/brian.allison/rs40/relap5.x";
            } else if (osver.contains("linux")) {
               exec = "relap5.x";
            } else if (osver.contains("windows")) {
                exec = "relap5.exe";
     
            }
     
           try{
     
            String Fileout = tfOutdta.getText();
            //Delete if tempFile exists
            File fileout = new File(Fileout);
              if (fileout.exists()){
                 fileout.delete();
              }   
          }catch(Exception e){
              // if any error occurs
     
          }
            //
            if (cbDelRstplt.isSelected()) {
             try{
     
            String Filerst = tfOutdta.getText();
            //Delete if File exists
            File filerst = new File(Filerst);
              if (filerst.exists()){
                 filerst.delete();
              }   
          }catch(Exception e){
                 // if any error occurs
     
          }   
            }
            String[] cmd = {exec, "-i", in, "-r", rst, "-o", out};
            if (tfStpdta.isVisible()) {
            String[] cmd2  = {exec, "-i", in, "-r", rst, "-o", out, "-s", strip};
            cmd = cmd2;
            } else if (cb3DGui.isSelected()) {
             String[] cmd3  = {exec, "-i", in, "-r", rst, "-o", out, "-n", "gui"};
             cmd = cmd3;
            } 
            System.out.println(strip);
        if 
     
    //
            try{
            Runtime.getRuntime().exec(cmd);
     
            } catch (IOException ex) {
          }

  2. #2
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    Default Re: check to see if a file exists using the current directory

    Check out the File class in the Java JDK.

    Regards,
    Jim

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    Default Re: check to see if a file exists using the current directory

    Quote Originally Posted by jim829 View Post
    Check out the File class in the Java JDK.

    Regards,
    Jim
    I am a newb to Java programming. where do I find info on file class.

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    Default Re: check to see if a file exists using the current directory

    Here is link to the API doc: https://docs.oracle.com/javase/8/docs/api/index.html
    Find the entry for the File class in the lower left window, click on it and the API doc for the class will show in the main window.
    If you don't understand my answer, don't ignore it, ask a question.

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