ConnectionWithDB

package com.company;

import java.sql.*;

/**
 * Created by Максим on 03.03.2016.
 */
public class ConnectionWithDB {
    public static ResultSet connect() throws SQLException {
    try {
        Class.forName("org.postgresql.Driver");
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    }
    Connection connection = null;
    try {
        connection = DriverManager.getConnection("jdbc:postgresql://localhost:5432/Authentication","postgres","postgres");
    } catch (SQLException e) {
        e.printStackTrace();
    }
    Statement st = connection.createStatement();
    ResultSet rs = st.executeQuery("select * from authentication");
    if (connection != null) {
        try {
            connection.close();
            return rs;
        } catch (SQLException ex) {
            ex.printStackTrace();
        }
    } else {
    }
        return rs;
    }



    public static void connect(String login, String password) throws SQLException {
        try {
            Class.forName("org.postgresql.Driver");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        Connection connection = null;
        try {
            connection = DriverManager.getConnection("jdbc:postgresql://localhost:5432/Authentication","postgres","postgres");
        } catch (SQLException e) {
            e.printStackTrace();
        }
        String query = "insert into authentication values (?,?)";
        PreparedStatement pStatement = connection.prepareStatement(query);
            pStatement.setString(1, login);
            pStatement.setString(2, password);
            pStatement.executeUpdate();
        if (connection != null) {
            try {
                connection.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
    }
}