src/java/org/mxchange/pizzaapplication/database/frontend/category/PizzaCategoryDatabaseFrontend.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.pizzaapplication.database.frontend.category;
  18
  19 import org.mxchange.pizzaapplication.category.product.ProductCategory;
  20 import java.io.IOException;
  21 import java.sql.ResultSet;
  22 import java.sql.SQLException;
  23 import java.text.MessageFormat;
  24 import java.util.Iterator;
  25 import org.mxchange.jcore.criteria.searchable.SearchCriteria;
  26 import org.mxchange.jcore.criteria.searchable.SearchableCritera;
  27 import org.mxchange.jcore.database.frontend.BaseDatabaseFrontend;
  28 import org.mxchange.jcore.database.result.DatabaseResult;
  29 import org.mxchange.jcore.database.result.Result;
  30 import org.mxchange.jcore.database.storage.Storeable;
  31 import org.mxchange.jcore.exceptions.BadTokenException;
  32 import org.mxchange.jcore.exceptions.UnsupportedDatabaseBackendException;
  33 import org.mxchange.pizzaapplication.category.Category;
  34 import org.mxchange.pizzaapplication.database.category.PizzaCategoryDatabaseConstants;
  35
  36 /**
  37  * Stores and retrieves Contact instances
  38  *
  39  * @author Roland Haeder
  40  */
  41 public class PizzaCategoryDatabaseFrontend extends BaseDatabaseFrontend implements CategoryFrontend {
  42         /**
  43          * Default constrcutor
  44          * @throws org.mxchange.jcore.exceptions.UnsupportedDatabaseBackendException If the configured backend is not supported
  45          * @throws java.sql.SQLException If any SQL error occurs
  46          */
  47         public PizzaCategoryDatabaseFrontend () throws UnsupportedDatabaseBackendException, SQLException {
  48                 // Trace message
  49                 this.getLogger().trace("CALLED!"); //NOI18N
  50
  51                 // Set "table" name
  52                 this.setTableName("category"); //NOI18N
  53
  54                 // Initalize backend
  55                 this.initBackend();
  56         }
  57
  58         /**
  59          * Adds given category title as new category, parent may be null if not selected.
  60          *
  61          * @param title Title of category
  62          * @param parent Parent id or null if not selected
  63          */
  64         @Override
  65         public void addCategory (final String title, final Integer parent) throws SQLException {
  66                 // Trace message
  67                 this.getLogger().trace(MessageFormat.format("title={0},parent={1} - CALLED!", title, parent));
  68
  69                 // Title should not be null
  70                 if (title == null) {
  71                         // Abort here
  72                         throw new NullPointerException("title is null");
  73                 }
  74
  75                 // Clear dataset from previous usage
  76                 this.clearDataSet();
  77
  78                 // Add title and parent
  79                 this.addToDataSet(PizzaCategoryDatabaseConstants.COLUMN_TITLE, title);
  80                 this.addToDataSet(PizzaCategoryDatabaseConstants.COLUMN_PARENT, parent);
  81
  82                 // Handle this over to the backend
  83                 Result<? extends Storeable> result = this.doInsertDataSet();
  84
  85                 // Debug message
  86                 this.getLogger().debug(MessageFormat.format("result={0}", result));
  87
  88                 // Trace message
  89                 this.getLogger().trace("EXIT!");
  90         }
  91
  92         /**
  93          * Shuts down the database layer
  94          * @throws java.sql.SQLException If an SQL error occurs
  95          * @throws java.io.IOException If any IO error occurs
  96          */
  97         @Override
  98         public void doShutdown () throws SQLException, IOException {
  99                 // Trace message
 100                 this.getLogger().trace("CALLED!"); //NOI18N
 101
 102                 // Shutdown backend
 103                 this.getBackend().doShutdown();
 104
 105                 // Trace message
 106                 this.getLogger().trace("EXIT!"); //NOI18N
 107         }
 108
 109         /**
 110          * Depending on column, an empty value may be converted to null
 111          *
 112          * @param key Key to check
 113          * @param value Value to check
 114          * @return Possible previous value or null
 115          */
 116         @Override
 117         public Object emptyStringToNull (final String key, final Object value) {
 118                 // Trace message
 119                 this.getLogger().trace(MessageFormat.format("key={0},value={1} - CALLED!", key, value));
 120
 121                 // Copy value
 122                 Object v = value;
 123
 124                 // Is the value empty?
 125                 if ((value instanceof String) && ("".equals(value))) {
 126                         // This value may need to be changed
 127                         switch (key) {
 128                                 case PizzaCategoryDatabaseConstants.COLUMN_PARENT: // Convert this
 129                                         v = null;
 130                                         break;
 131                         }
 132                 }
 133
 134                 // Trace message
 135                 this.getLogger().trace(MessageFormat.format("v={0} - EXIT!", v));
 136
 137                 // Return it
 138                 return v;
 139         }
 140
 141         @Override
 142         @SuppressWarnings ("unchecked")
 143         public Iterator<Category> getCategories () throws IOException, BadTokenException, SQLException {
 144                 // Trace message
 145                 this.getLogger().trace("CALLED!"); //NOI18N
 146
 147                 // Instance search criteria
 148                 SearchableCritera critera = new SearchCriteria();
 149
 150                 // Run the query
 151                 Result<? extends Storeable> result = this.getBackend().doSelectByCriteria(critera);
 152
 153                 // Debug message
 154                 this.getLogger().debug(MessageFormat.format("result={0}", result)); //NOI18N
 155
 156                 // Get iterator
 157                 Iterator<?> iterator = result.iterator();
 158
 159                 // Trace message
 160                 this.getLogger().trace(MessageFormat.format("iterator={0} - EXIT!", iterator)); //NOI18N
 161
 162                 // Get iterator and return it
 163                 return (Iterator<Category>) iterator;
 164         }
 165
 166         /**
 167          * Gets a Result back from given ResultSet instance
 168          *
 169          * @param resultSet ResultSet instance from SQL driver
 170          * @return A typorized Result instance
 171          * @throws java.sql.SQLException If any SQL error occurs
 172          */
 173         @Override
 174         public Result<? extends Storeable> getResultFromSet (final ResultSet resultSet) throws SQLException {
 175                 // Trace message
 176                 this.getLogger().trace(MessageFormat.format("resultSet={0} - CALLED!", resultSet));
 177
 178                 // Init result instance
 179                 Result<? extends Storeable> result = new DatabaseResult();
 180
 181                 // Reset result set before first row
 182                 resultSet.beforeFirst();
 183
 184                 // "Walk" through all entries
 185                 while (resultSet.next()) {
 186                         // Get id, title and parent id
 187                         Integer id = resultSet.getInt(PizzaCategoryDatabaseConstants.COLUMN_ID);
 188                         String title = resultSet.getString(PizzaCategoryDatabaseConstants.COLUMN_TITLE);
 189                         Integer parent = resultSet.getInt(PizzaCategoryDatabaseConstants.COLUMN_PARENT);
 190
 191                         // Debug message
 192                         this.getLogger().debug(MessageFormat.format("id={0},title={1},parent={2}", id, title, parent));
 193
 194                         // Instance new object
 195                         Category category = new ProductCategory(id, title, parent);
 196
 197                         // Debug log
 198                         this.getLogger().debug(MessageFormat.format("category={0}", category));
 199
 200                         // Add it to result
 201                         result.add(category);
 202                 }
 203
 204                 // Trace message
 205                 this.getLogger().trace(MessageFormat.format("result({0})={1} - EXIT!", result.size(), result));
 206
 207                 // Return result
 208                 return result;
 209         }
 210
 211         /**
 212          * Checks if given category title is already used
 213          *
 214          * @param title Title to check
 215          * @return Whether the title has been used
 216          */
 217         @Override
 218         public boolean isCategoryTitleUsed (final String title) throws IOException, SQLException, BadTokenException {
 219                 // Trace message
 220                 this.getLogger().trace(MessageFormat.format("title={0} - CALLED!", title));
 221
 222                 // Get search criteria
 223                 SearchableCritera criteria = new SearchCriteria();
 224
 225                 // Add criteria
 226                 criteria.addCriteria(PizzaCategoryDatabaseConstants.COLUMN_TITLE, title);
 227
 228                 // Only one entry is find
 229                 criteria.setLimit(1);
 230
 231                 // Run it on backend
 232                 Result<? extends Storeable> result = this.getBackend().doSelectByCriteria(criteria);
 233
 234                 // Debug log
 235                 this.getLogger().debug(MessageFormat.format("result({0}={1}", result, result.size()));
 236
 237                 // Now check size of the result
 238                 boolean isFound = (result.size() == 1);
 239
 240                 // Trace message
 241                 this.getLogger().trace(MessageFormat.format("isFound={0} - EXIT!", isFound));
 242
 243                 // Return it
 244                 return isFound;
 245         }
 246
 247         /**
 248          * Parses given line from database backend into a Storeable instance. Please
 249          * note that not all backends need this.
 250          *
 251          * @param line Line from database backend
 252          * @return A Storeable instance
 253          */
 254         @Override
 255         public Storeable parseLineToStoreable (final String line) throws BadTokenException {
 256                 // Trace message
 257                 this.getLogger().trace(MessageFormat.format("line={0} - CALLED!", line)); //NOI18N
 258
 259                 // Call inner method
 260                 Category category = this.parseLineToCategory(line);
 261
 262                 // Debug message
 263                 this.getLogger().trace(MessageFormat.format("category={0} - EXIT!", category)); //NOI18N
 264
 265                 // Return it
 266                 return category;
 267         }
 268
 269         /**
 270          * Parses given line to a Category instance
 271          *
 272          * @param line Raw, decoded line from a file-based backend
 273          * @return A Category instance from given line
 274          */
 275         private Category parseLineToCategory (final String line) {
 276                 throw new UnsupportedOperationException(MessageFormat.format("Not supported yet: line={0}", line)); //NOI18N
 277         }
 278 }