MySQL.java

package com.skin_98.MySQL.DataBase;

import java.io.File;
import java.io.IOException;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.bukkit.configuration.file.FileConfiguration;
import org.bukkit.configuration.file.YamlConfiguration;

import com.mysql.jdbc.Connection;
import com.mysql.jdbc.PreparedStatement;

/**
* MySQL adatbázis util
*/
public class MySQL {

        //Alap változók
        public String HOST;
        public String PORT;
        public String DATABASE;
        public String USERNAME;
        private String PASSWORD; //<- Rejtett
        public int TIMEOUT;

        //Kapcsolat
        private Connection conn;

        //Instance
        private static MySQL instance = null;

        /**
         * Inicializálás
         * @throws Exception
         */
        public void init() throws Exception {
            if(instance != null) {
                throw new Exception("MySQL has already initialized!");
            }
            File MySQL_FILE = new File("plugins","MySQL.yml");
            FileConfiguration sql_file = YamlConfiguration.loadConfiguration(MySQL_FILE);

            //Konfiguráció alapértelmezett értékei
            String db = "MySQL.";
            sql_file.addDefault(db + "host", "127.0.0.1");
            sql_file.addDefault(db + "port", "3306");
            sql_file.addDefault(db + "username", "user");
            sql_file.addDefault(db + "password", "password");
            sql_file.addDefault(db + "database", "database");
            sql_file.addDefault(db + "timeout", new Integer(10000));

            sql_file.options().copyDefaults(true);
            try {
                sql_file.save(MySQL_FILE);
            } catch(IOException e) {
                e.printStackTrace();
            }

            this.HOST = sql_file.getString(db + "host");
            this.PORT = sql_file.getString(db + "port");
            this.USERNAME = sql_file.getString(db + "username");
            this.PASSWORD = sql_file.getString(db + "password");
            this.DATABASE = sql_file.getString(db + "database");
            this.TIMEOUT = sql_file.getInt(db + "password");

            this.openConnection();
            instance = this;
            System.out.println("[MySQL] This utility is created by Gerviba!");
        }

        /**
         * Kapcsolat megnyitása
         */
        public Connection openConnection() throws Exception{
            //MySQL URI generálása config alapján
            Class.forName("com.mysql.jdbc.Driver");
            Connection conn = (Connection) DriverManager.getConnection("jdbc:mysql://" + this.HOST + ":" + this.PORT + "/" + this.DATABASE+"?autoReconnect=true", this.USERNAME, this.PASSWORD);
            this.conn = conn;
            this.conn.setAutoReconnect(true);
            this.conn.setConnectTimeout(TIMEOUT);
            return null;
        }

        /**
         * Kapcsolat getter
         * @return Kapcsolat
         */
        public Connection getConnection() {
            try {
                if(this.conn == null || !this.conn.isValid(TIMEOUT)) {
                    System.out.println("[MySQL] Reconnecting!");
                    this.openConnection();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            return this.conn;
        }

        /**
         * Kapcsolat checker
         * @return true hogyha van kapcsolat
         */
        public boolean hasConnection() {
            try {
                return this.conn != null || this.conn.isValid(1);
            } catch(SQLException e) {
                return false;
            }

        }

        /**
         * Query kiadása
         * @param query INSERT, DELETE, UPDATE és egyéb query
         */
        public void query(String query) {
            PreparedStatement st = null;
            try {
                st = (PreparedStatement) this.getConnection().prepareStatement(query);
                st.executeUpdate();
            } catch(SQLException e) {
                System.err.println("MySQL Query error! {" + query + "}");
                e.printStackTrace();
            } finally {
                this.closeRessources(null, st);
            }
        }

        /**
         * Források bezárása
         * @param rs ResultSet
         * @param st PreparedStatement
         */
        public void closeRessources(ResultSet rs, PreparedStatement st) {
            if (rs != null) {
                try {
                    rs.close();
                } catch(SQLException e) {}
            }
            if (st != null) {
                try {
                    st.close();
                } catch(SQLException e) {}
            }
        }

        /**
         * Szétkapcsolás
         */
        public void closeConnection() {
            try {
                this.conn.close();
            } catch(SQLException e) {
                e.printStackTrace();
            } finally {}
            this.conn = null;
        }

        /**
         * Instance getter
         * @return MySQL
         */
        public static MySQL getInstance() {
            return instance;
        }

        /**
         * Tábla ellenőrző
         * @param table Tábla neve
         * @return true, hogyha létezik és false, hogyha nem
         * @throws Exception
         */
        public boolean isTableExists(String table) throws Exception {
            ResultSet rs = null;
            PreparedStatement st = null;
            try {
                st = (PreparedStatement) MySQL.getInstance().getConnection().prepareStatement("SHOW TABLES LIKE '"+table+"'");
                rs = st.executeQuery();
                rs.first();
                return rs.getRow() != 0;
            } catch(Exception ex) {
                throw ex;
            } finally {
                MySQL.getInstance().closeRessources(rs, st);
            }
        }

        /**
         * Tábla ellenőrző
         * @param table Tábla neve
         * @return true, hogyha létezik és false, hogyha nem vagy ha hiba történik.
         */
        public boolean isTableExistsSafe(String table) {
            ResultSet rs = null;
            PreparedStatement st = null;
            try {
                st = (PreparedStatement) MySQL.getInstance().getConnection().prepareStatement("SHOW TABLES LIKE '"+table+"'");
                rs = st.executeQuery();
                rs.first();
                return rs.getRow() != 0;
            } catch(Exception ex) {
                ex.printStackTrace();
            } finally {
                MySQL.getInstance().closeRessources(rs, st);
            }
            return false;
        }

}