src/org/mxchange/jshopcore/model/customer/CustomerUtils.java

   1 /*
   2  * Copyright (C) 2015 Roland Haeder
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17 package org.mxchange.jshopcore.model.customer;
  18
  19 import java.sql.Connection;
  20 import java.sql.PreparedStatement;
  21 import java.sql.ResultSet;
  22 import java.sql.SQLException;
  23 import java.text.MessageFormat;
  24 import org.mxchange.jcore.BaseFrameworkSystem;
  25 import org.mxchange.jcoreeelogger.beans.local.logger.LoggerBeanLocal;
  26
  27 /**
  28  * An utilities class for customers
  29  *
  30  * @author Roland Haeder
  31  */
  32 public class CustomerUtils extends BaseFrameworkSystem {
  33
  34         /**
  35          * No instance from this class
  36          */
  37         private CustomerUtils () {
  38         }
  39
  40         /**
  41          * Generates an unique customer number by checking is existence
  42          *
  43          * @param connection Connection instance
  44          * @param logger Logger instance
  45          * @return Generated customer number (not used before)
  46          * @throws java.sql.SQLException If any SQL error occured
  47          */
  48         public static String generateCustomerNumber (final Connection connection, final LoggerBeanLocal logger) throws SQLException {
  49                 // logger cannot be null
  50                 if (null == logger) {
  51                         // Abort here
  52                         throw new NullPointerException("logger is null");
  53                 }
  54
  55                 // Trace message
  56                 logger.logTrace(MessageFormat.format("generateCustomerNumber: connection={0},logger={1} - CALLED!", connection, logger));
  57
  58                 // connection cannot be null
  59                 if (null == connection) {
  60                         // Abort here
  61                         throw new NullPointerException("connection is null");
  62                 }
  63
  64                 // Prepare statement
  65                 PreparedStatement statement = connection.prepareStatement("SELECT `id` FROM `customer` WHERE `customer_number` = ? LIMIT 1");
  66
  67                 // Generate number
  68                 String customerNumber = Long.toString(Math.round(Math.random() * 100000)) + "-" +  Long.toString(Math.round(Math.random() * 1000));
  69
  70                 // Default is found
  71                 boolean isFound = true;
  72
  73                 // Is the number used?
  74                 while (isFound) {
  75                         // Debug message
  76                         logger.logDebug(MessageFormat.format("generateCustomerNumber: customerNumber={0}", customerNumber));
  77
  78                         // Insert customer number
  79                         statement.setString(0, customerNumber);
  80
  81                         // Find it
  82                         statement.execute();
  83
  84                         // Get result
  85                         ResultSet result = statement.getResultSet();
  86
  87                         // Rewind it
  88                         result.beforeFirst();
  89
  90                         // Found a record?
  91                         if (result.isLast()) {
  92                                 // Not found
  93                                 isFound = false;
  94                                 break;
  95                         }
  96
  97                         // Generate new number
  98                         customerNumber = Long.toString(Math.round(Math.random() * 100000)) + "-" +  Long.toString(Math.round(Math.random() * 1000));
  99                 }
 100
 101                 // Trace message
 102                 logger.logTrace(MessageFormat.format("generateCustomerNumber: customerNumber={0} - EXIT!", customerNumber));
 103
 104                 // Found one
 105                 return customerNumber;
 106         }
 107 }