postfix-api/src/main/java/de/gurkengewuerz/postfix_rest_send/MySQL.java

package de.gurkengewuerz.postfix_rest_send;

import java.sql.*;
import java.util.logging.Logger;

/**
 * Simple wrapper for database abstraction.
 *
 * @author Nijiko
 * @url https://raw.githubusercontent.com/iConomy/SimpleShop/master/com/nijiko/simpleshop/database/Wrapper.java
 */
public class MySQL {
    private static final Logger log = Logger.getLogger("MySQL");

    /**
     * Database Types
     */
    public enum Type {
        SQLITE,
        MYSQL
    }

    ;

    /**
     * Fetch type from string.
     *
     * @param type
     * @return
     */
    public static Type getType(String type) {
        for (Type dbType : Type.values()) {
            if (dbType.toString().equalsIgnoreCase(type)) {
                return dbType;
            }
        }

        return Type.SQLITE;
    }

    /*
     * Database Settings
     */
    public Type database = null;

    /*
     * Database Connection Settings
     */
    private String db;
    private String user;
    private String pass;

    /*
     * Database Memory
     */
    private Connection connection;
    private Statement Stmt;
    private PreparedStatement Statement;
    private ResultSet ResultSet;

    /**
     * Create a new instance of the wrapper for usage.
     *
     * @param database
     * @param db
     * @param user
     * @param pass
     */
    public MySQL(Type database, String db, String user, String pass) {
        this.database = database;
        this.db = db;
        this.user = user;
        this.pass = pass;
    }

    /**
     * Initialize the wrapper
     *
     * @return Connection
     * @throws ClassNotFoundException
     * @throws SQLException
     */
    public void initialize() {
        try {
            this.connection();
        } catch (SQLException ex) {
            log.severe("[" + this.database.toString() + " Database] Failed to connect: " + ex);
        } catch (ClassNotFoundException e) {
            log.severe("[" + this.database.toString() + " Database] Connector not found: " + e);
        }
    }

    /**
     * Connect to the database, return connection.
     *
     * @return Connection
     * @throws ClassNotFoundException
     * @throws SQLException
     */
    private Connection connection() throws ClassNotFoundException, SQLException {
        if (this.database.equals(database.SQLITE)) {
            Class.forName("org.sqlite.JDBC");
            this.connection = DriverManager.getConnection(this.db);
        } else {
            Class.forName("com.mysql.jdbc.Driver");
            this.connection = DriverManager.getConnection(this.db, this.user, this.pass);
        }

        return this.connection;
    }

    /**
     * Check to see if table exists.
     *
     * @param table
     * @return boolean
     */
    public boolean checkTable(String table) {
        initialize();

        try {
            DatabaseMetaData dbm = this.connection.getMetaData();
            this.ResultSet = dbm.getTables(null, null, table, null);
            return this.ResultSet.next();
        } catch (SQLException ex) {
            log.severe("[" + this.database.toString() + " Database] Table check failed: " + ex);
        } finally {
            this.close();
        }

        return false;
    }

    /**
     * Execute pure SQL String.
     *
     * @param query
     * @return
     */
    public ResultSet executeQuery(String query) {
        initialize();

        try {
            this.Statement = this.connection.prepareStatement(query);

            return this.Statement.executeQuery();
        } catch (SQLException ex) {
            log.severe("[" + this.database.toString() + " Database] Could not execute query: " + ex);
        }

        return null;
    }

    /**
     * Execute Query with variables.
     *
     * @param query
     * @param variables
     * @return
     */
    public ResultSet executeQuery(String query, Object... variables) {
        initialize();

        try {
            this.Statement = this.connection.prepareStatement(query);
            int i = 1;
            for (Object obj : variables) {
                this.Statement.setObject(i, obj);
                i++;
            }
            return this.Statement.executeQuery();
        } catch (SQLException ex) {
            log.severe("[" + this.database.toString() + " Database] Could not execute query: " + ex);
        }

        return null;
    }

    /**
     * Execute pure SQL String.
     *
     * @param query
     * @return
     */
    public int executeUpdate(String query) {
        initialize();

        try {
            this.Stmt = this.connection.createStatement();
            return this.Stmt.executeUpdate(query);
        } catch (SQLException ex) {
            log.severe("[" + this.database.toString() + " Database] Could not execute query: " + ex);
        }

        return 0;
    }

    /**
     * Execute Query with variables.
     *
     * @param query
     * @param variables
     * @return
     */
    public int executeUpdate(String query, Object... variables) {
        initialize();

        try {
            this.Statement = this.connection.prepareStatement(query);
            int i = 1;

            for (Object obj : variables) {
                this.Statement.setObject(i, obj);
                i++;
            }

            return this.Statement.executeUpdate();
        } catch (SQLException ex) {
            log.severe("[" + this.database.toString() + " Database] Could not execute query: " + ex);
        }

        return 0;
    }

    public void close() {
        try {
            if (this.Statement != null) {
                this.Statement.close();
            }

            if (this.ResultSet != null) {
                this.ResultSet.close();
            }

            if (this.connection != null) {
                this.connection.close();
            }

        } catch (SQLException ex) {
            log.severe("[" + this.database.toString() + " Database] Failed to close connection: " + ex);

            // Close anyway.
            this.connection = null;
            this.Statement = null;
            this.ResultSet = null;
        }
    }

    protected void finalize() {
        close();
    }
}