I'm trying to make a money mod and I need to be able to store the variable in a file. Whats the best / easiest thing to use to do this, java db, yaml, or xml? Also I cant figure out how to use any of them to save and load data so any tutorials will be very helpful.

I think im going to try java db, im trying to use http://docs.oracle.com/javadb/10.8.2.2/getstart/index.html , so far I have

package economy.common;

import java.sql.*;

public class Data {

public static void init() throws SQLException{

    String sqlCreate = "CREATE TABLE IF NOT EXISTS Economy"
            + "  (player           VARCHAR(20),"
            + "   amount            INTEGER)";

	try {
		Connection db = DriverManager.getConnection("jdbc:derby:Economy;create=true");
		db.createStatement().execute(sqlCreate);
		System.out.println("Economy successfully connected to the database");
		} 
	catch (Throwable e) {	
		System.out.println("Economy failed to connected to the database");
		}

}

public void load() throws SQLException {
	Connection db = DriverManager.getConnection("jdbc:derby:economy;create=true");



	db.close();
}


public void save(String player, String amount) throws SQLException {
	Connection db = DriverManager.getConnection("jdbc:derby:economy;create=true");



	db.close();
}

}

 

but it wont start and connect to the database. Why is it not starting it?

Why use a db? For minecraft servers that is more than you need, you just need packet handling and a local map. I recommended using minecraft's built in compressor for saving and loading. maps can be saved directly to the disk and reloaded:

http://www.minecraftforge.net/forum/index.php/topic,3211.msg21401.html#msg21401

 

That is the easiest option because after the save and load, you just use the map normally. Forge offers an event on the event bus so you can save when the world saves.

Could you give me the link to a tutorial because I can't find any.

The code I posted is everything you need to know. If you need more info, your issue stems deeper than this...

that not what I was looking for I need to save the player names and how much money they have into the file and I need to load the file then change the amount of money and save it again.

I am not going to hold your hand, look up how maps work, and learn how java works in general, and then maybe I will help.

If you didn't want to help then please don't post