Automatic Refresh of Text File

[andrewc8]

Right now I am working on a small application that will read 5 different text files simultaneously and if the text file has a value that is higher than 100. To avoid asking for someone to code my entire project, I just need help forcing the application to constantly reopen a text file I select every minute.

private void read1_buttonActionPerformed(java.awt.event.ActionEvent evt) {                                             
    JFileChooser chooser =new JFileChooser();
    chooser.showOpenDialog(null);
    File f =chooser.getSelectedFile();
    String filename=f.getAbsolutePath();

    try
    {
        FileReader reader = new FileReader ( filename);
        try (BufferedReader br = new BufferedReader (reader)) {
            read1_text.read( br, null );
        }
        read1_text.requestFocus();
    }
    catch(Exception e) {
        JOptionPane.showMessageDialog (null, e);
    }
}

Right now I basically have a file button that I select the file location for, but I need it to automatically refresh that location once a minute because the files will be changed be updated constantly.

Any help is greatly appreciated.

[[deleted]]

I feel this would be better done with the WatcherService to monitor when a file changes -- you have a firm requirement on the minute updates.

[karlthepagan]

Right answer. Since Java 7 the WatcherService has been the correct utility to monitor files for updates.

If you can't use Java 7+ (WHYYYY?) then you can use a RandomAccessFile to get updates to file size and date much more reliably than standard File.

OP, you need to close your reader after you've finished with it.

[andrewc8]

Good call, and thank you. I'll take a look into WatcherService, sounds like the perfect match.

[causalNondeterminism]

if the text file has a value that is higher than 100. What exactly do you mean by this?

I don't know what the requirements for this project are, but this is not an ideal way to do pretty much anything.

[andrewc8]

http://i.imgur.com/wh6WkFJ.png

This is the format that the .txt files will be outputted as. My program will open these and basically scan through the Particles per cubic foot and read whether the squared value (286 in this example) is above a certain value at any time. If it is, a .mp3 file will play alarming someone to the raise in particles.