Easily Open a File in Java

Say you wanted to open a file in Java, either for reading or writing. But it’s not clear how to do it, and whether you need a GUI, and blah blah blah, wouldn’t it be nice to just find a minimal example? ¬†Well then, here you go.

import javax.swing.*;   // for JFileChooser
import java.io.*;       // for File
import java.util.*;     // for Scanner (if you want to read it in)

class FileOpener {

    public static void main(String[] args) {
        JFileChooser fc = new JFileChooser();
        int returnVal = fc.showOpenDialog(null);
        if(returnVal == JFileChooser.APPROVE_OPTION) {
            File f = fc.getSelectedFile();
            // it's in your hands now...

Solid. Now say you want to read from the file:

            try {
                // read in the file
                Scanner s = new Scanner(f);
                String str = s.nextLine();
                // ...
            } catch(FileNotFoundException e) {
                // Couldn't find the file for some reason

Or writing to the file:

            try {
                FileWriter fw = new FileWriter(f);
                fw.write("Hello, World!");
                // ...
            } catch(IOException e) {
                // didn't work

Ta-da! Protip: If you’re using this as part of a GUI with a Component “comp” showing your main GUI screen, set “comp” to be the parent of the filechooser dialog by calling fc.showOpenDialog(comp);.

Other protip: if you really want, you can subject yourself to the official tutorial here.


Painless Backups on Linux

Being new to Linux, I’ve been trying to discover the “right” way to do things without a) becoming an expert hacker overnight, b) installing and configuring a bunch of complex programs, c) destroying my computer.

Well, here’s one task down: Turns out there is a very easy way to do simple backups on Linux. Continue reading