JFileChooser to open multiple txt files

Question

How can I use JFileChooser to open two text files and after I selected these files, I want to compare them, show on the screen etc. Is this possible?

Pepsinate

Answer 1

You can have your JFileChooser select multiple files and return an array of File objects instead of one

JFileChooser chooser = new JFileChooser();
chooser.setMultiSelectionEnabled(true);
chooser.showOpenDialog(frame);
File[] files = chooser.getSelectedFiles();

The method showOpenDialog(frame) only returns once you click the ok button

EDIT

So do this:

JFileChooser chooser = new JFileChooser();
chooser.setMultiSelectionEnabled(true);
chooser.showOpenDialog(frame);
File[] files = chooser.getSelectedFiles();
if(files.length >= 2) {
    compare(readFileAsList(files[0]), readFileAsList(files[1]));
}

And change your readFileAsList to:

private static List<String> readFileAsList(File file) throws IOException {
    final List<String> ret = new ArrayList<String>();
    final BufferedReader br = new BufferedReader(new FileReader(file));
    try {
        String strLine;
        while ((strLine = br.readLine()) != null) {
            ret.add(strLine);
        }
        return ret;
    } finally {
        br.close();
    }
}

Stockholder

What you get from the file chooser is an array of Files. you can access them using compare(readFileAsList(files[0]), readFileAsList(files[1])); but you'd need to change readFileAsList to accept File instead of String – Stockholder

docs.oracle.com/cd/E26232_01/doc.11122/easjavaapi/com/essbase/… If you're using Java's built in method, you don't need to do anything as it already accepts File objects But it's really difficult to help you without seeing your current code – Stockholder

Also, when you ask a question, once someone gave you the right answer here in StackOverflow, please mark it as accepted (the V under the answer) it helps if someone searches for a similar question, he can tell that this answer is correct – Stockholder

Just edit your answer to include your code, and i'll try and help you – Stockholder

la bla bla firstly thank you so much but is it neccessary that i change this part? leftList = (ArrayList<String>) readFileAsList("C:\\Files\\file1.txt"); rightList = (ArrayList<String>) readFileAsList("C:\\Files\\file2.txt"); – Pepsinate

also choosing a file only I only choose file1.txt after that programme compiles, i cant choose both txt files because of error – Pepsinate

also i cant choose any file from D driver – Pepsinate

If you won't change leftList = .. and rightList = .. then you will just be selecting the files you write in your code. not using the JFileChooser. What error are you getting? send me an email: [email protected] so we won't flood the comments here. I'll answer as soon as I can. – Stockholder

Also when I change my code at your comment, the compare method doesnt not compile – Pepsinate

Answer 2

You can use:

JFileChooser chooser = new JFileChooser();
chooser.setMultiSelectionEnabled(true);

// Show the dialog; wait until dialog is closed
chooser.showOpenDialog(frame);

// Retrieve the selected files.
File[] files = chooser.getSelectedFiles();

You can then use the file handles returned to do the compare.

Agitate

Answer 3

In my case I solved it declaring frame as an initialized local variable set to null:

JFileChooser chooser = new JFileChooser();
chooser.setMultiSelectionEnabled(true);

Component frame = null;

chooser.showOpenDialog(frame);
File[] files = chooser.getSelectedFiles();

Blasphemous