[Tutorial][Java 7 Only] Storing locations/information in a csv like database style

I don't know why but whenever I get on the forums I always see people asking how to save locations(or other information) to a file, so I just decided to make a small tutorial for those who want to learn a bit of the new Files and Path package in Java 7 and MORE importantly how to save data using those packages.

So for this example I'll just use a simple collection of locations, you will want to store the world,x,y,z into a file format with a delimiter of your choice, in my case a semi-colon like this :

world1;x1;y1;z1
world2;x2;y2;z2
......
.....

Create a new class and name LocationManager(or however you like),and assume you have a collection of locations like this:

Code:java

public static ArrayList<Location> locations = new ArrayList<Location>();

Define a Path object to your desired config file name:
I have also made a charset object reference because we will be using that a lot later on.

Code:java

private static final Path configPath = Paths.get(<PLUGININSTANCEHERE>.getDataFolder().toPath() + "/locations.yml");
private static final Charset charset = Charset.forName("UTF-8");

NOTE: Creating a Path object does not create the file, it only creates a reference to the file you want to process whether it is existent or non-existent!

Now to make a custom saveDefaults() method for your locations.yml:

Code:java

public static void saveDefaults() {
    if (Files.notExists(configPath)) {
        try {
            Files.createFile(configPath);
        } catch (IOException e) {
            //Handle the exception yourself
        }
    }
}

The code is pretty much self explanatory, but all this does is that it checks if the locations.yml exists, if not it will create a new empty file.
Ok so now we want to convert our location the format above:

Code:java

private static String locationToStorage(Location location){
    ArrayList<String> locationInfo = new ArrayList<String>();
    StringBuilder stringBuilder = new StringBuilder();
    for(String string : locationInfo){
        stringBuilder.append(string);
        stringBuilder.append(";");
    }
    return stringBuilder.toString();
}

Now we want to save the arraylist of locations to the file:

Code:java

private static void save() {
        try {
            BufferedWriter bufferedWriter = Files.newBufferedWriter(configPath, charset, StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING);
            for (Location location : locations) {
                String locationInfo = locationToStorage(location);
                bufferedWriter.append(locationInfo);
                bufferedWriter.newLine();
            }
            bufferedWriter.close();
        } catch (IOException e) {
            //Handle the exception yourself
        }
    }

Good so now you have a file with locations in it so how do we load it back? Easy

Code:java

public static void loadLocations() {
    try {
        saveDefaults();
        BufferedReader bufferedReader = Files.newBufferedReader(configPath, charset);
        String line;
        while ((line = bufferedReader.readLine()) != null) {
            String[] locationInfo = line.split(";");
            if(locationInfo.length < 4) continue; //If the string isn't longer than 4 skip it
            World world = Bukkit.getServer().getWorld(locationInfo[0]);
            if (world == null) {
                Path worldFolder = Paths.get(Bukkit.getServer().getWorldContainer().toPath() + "/" + locationInfo[1]);
                if (Files.exists(worldFolder)) {
                    Bukkit.getServer().createWorld(new WorldCreator(locationInfo[0]));
                    world = Bukkit.getServer().getWorld(locationInfo[0]);
                } else {
                    // Do something if server could not load world
                }
            }
            int x = Integer.parseInt(locationInfo[1]);
            int y = Integer.parseInt(locationInfo[2]);
            int z = Integer.parseInt(locationInfo[3]);
 
            Location location = new Location(world,x,y,z);
 
            locations.add(location);
        }
    } catch (IOException e) {
        //Handle exception yourself
    }
    // Do something if loading was a success
}

And so all you need to do add LocationManager.saveDefaults() and LocationManager.loadLocations to your onEnable() and LocationManager.save() to your onDisable(), though I prefer to save every time I add a new object to the arraylist to make sure its saved.

If you really don't know you save locations like this now:

Code:java

LocationManager.locations.add(location);
LocationManager.save();

Well that's it! Remember this only works if you compile on Java 7, that's goes for the server also!Hope you learned some java lol, waicool20 signing out.