Source for org.jfree.report.modules.misc.tablemodel.ScrollableResultSetTableModel

   1: /**
   2:  * ========================================
   3:  * JFreeReport : a free Java report library
   4:  * ========================================
   5:  *
   6:  * Project Info:  http://reporting.pentaho.org/
   7:  *
   8:  * (C) Copyright 2000-2007, by Object Refinery Limited, Pentaho Corporation and Contributors.
   9:  *
  10:  * This library is free software; you can redistribute it and/or modify it under the terms
  11:  * of the GNU Lesser General Public License as published by the Free Software Foundation;
  12:  * either version 2.1 of the License, or (at your option) any later version.
  13:  *
  14:  * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
  15:  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  16:  * See the GNU Lesser General Public License for more details.
  17:  *
  18:  * You should have received a copy of the GNU Lesser General Public License along with this
  19:  * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  20:  * Boston, MA 02111-1307, USA.
  21:  *
  22:  * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
  23:  * in the United States and other countries.]
  24:  *
  25:  * ------------
  26:  * $Id: ScrollableResultSetTableModel.java 2725 2007-04-01 18:49:29Z taqua $
  27:  * ------------
  28:  * (C) Copyright 2000-2005, by Object Refinery Limited.
  29:  * (C) Copyright 2005-2007, by Pentaho Corporation.
  30:  */
  31: package org.jfree.report.modules.misc.tablemodel;
  32: 
  33: import java.sql.ResultSet;
  34: import java.sql.ResultSetMetaData;
  35: import java.sql.SQLException;
  36: import javax.swing.table.AbstractTableModel;
  37: 
  38: import org.jfree.util.Log;
  39: 
  40: /**
  41:  * A tableModel which is backed up by a java.sql.ResultSet. Use this to directly feed your
  42:  * database data into JFreeReport. If you have trouble using this TableModel and you have
  43:  * either enough memory or your query result is not huge, you may want to use
  44:  * <code>ResultSetTableModelFactory.generateDefaultTableModel (ResultSet rs)</code>. That
  45:  * implementation will read all data from the given ResultSet and keep that data in
  46:  * memory.
  47:  * <p/>
  48:  * Use the close() function to close the ResultSet contained in this model.
  49:  *
  50:  * @author Thomas Morgner
  51:  */
  52: public class ScrollableResultSetTableModel extends AbstractTableModel
  53:         implements CloseableTableModel
  54: {
  55:   /**
  56:    * The scrollable ResultSet source.
  57:    */
  58:   private ResultSet resultset;
  59:   /**
  60:    * The ResultSetMetaData object for this result set.
  61:    */
  62:   private ResultSetMetaData dbmd;
  63:   /**
  64:    * The number of rows in the result set.
  65:    */
  66:   private int rowCount;
  67:   /**
  68:    * Defines the column naming mode.
  69:    */
  70:   private final boolean labelMapMode;
  71:   /**
  72:    * The column types as read from the result set.
  73:    */
  74:   private Class[] types;
  75: 
  76:   /**
  77:    * Constructs the model.
  78:    *
  79:    * @param resultset    the result set.
  80:    * @param labelMapMode defines, whether to use column names or column labels to compute
  81:    *                     the column index.
  82:    * @throws SQLException if there is a problem with the result set.
  83:    */
  84:   public ScrollableResultSetTableModel (final ResultSet resultset,
  85:                                         final boolean labelMapMode)
  86:           throws SQLException
  87:   {
  88:     this.labelMapMode = labelMapMode;
  89:     if (resultset != null)
  90:     {
  91:       updateResultSet(resultset);
  92:     }
  93:     else
  94:     {
  95:       close();
  96:     }
  97:   }
  98: 
  99:   /**
 100:    * Creates a new scrollable result set with no resultset assigned and the specified
 101:    * label map mode.
 102:    *
 103:    * @param labelMapMode defines, whether to use column names or column labels to compute
 104:    *                     the column index.
 105:    */
 106:   protected ScrollableResultSetTableModel (final boolean labelMapMode)
 107:   {
 108:     this.labelMapMode = labelMapMode;
 109:   }
 110: 
 111:   /**
 112:    * Returns the column name mode used to map column names into column indices. If true,
 113:    * then the Label is used, else the Name is used.
 114:    *
 115:    * @return true, if the column label is used for the mapping, false otherwise.
 116:    *
 117:    * @see ResultSetMetaData#getColumnLabel
 118:    * @see ResultSetMetaData#getColumnName
 119:    */
 120:   public boolean isLabelMapMode ()
 121:   {
 122:     return labelMapMode;
 123:   }
 124: 
 125:   /**
 126:    * Updates the result set in this model with the given ResultSet object.
 127:    *
 128:    * @param resultset the new result set.
 129:    * @throws SQLException if there is a problem with the result set.
 130:    */
 131:   public void updateResultSet (final ResultSet resultset)
 132:           throws SQLException
 133:   {
 134:     if (this.resultset != null)
 135:     {
 136:       close();
 137:     }
 138: 
 139:     this.resultset = resultset;
 140:     this.dbmd = resultset.getMetaData();
 141: 
 142:     if (resultset.last())
 143:     {
 144:       rowCount = resultset.getRow();
 145:     }
 146:     else
 147:     {
 148:       rowCount = 0;
 149:     }
 150: 
 151:     fireTableStructureChanged();
 152:   }
 153: 
 154:   /**
 155:    * Clears the model of the current result set. The resultset is closed.
 156:    */
 157:   public void close ()
 158:   {
 159:     // Close the old result set if needed.
 160:     if (resultset != null)
 161:     {
 162:       try
 163:       {
 164:         resultset.close();
 165:       }
 166:       catch (SQLException e)
 167:       {
 168:         // Just in case the JDBC driver can't close a result set twice.
 169:         //  e.printStackTrace();
 170:       }
 171:     }
 172:     resultset = null;
 173:     dbmd = null;
 174:     rowCount = 0;
 175:     fireTableStructureChanged();
 176:   }
 177: 
 178:   /**
 179:    * Get a rowCount. This can be a very expensive operation on large datasets. Returns -1
 180:    * if the total amount of rows is not known to the result set.
 181:    *
 182:    * @return the row count.
 183:    */
 184:   public int getRowCount ()
 185:   {
 186:     if (resultset == null)
 187:     {
 188:       return 0;
 189:     }
 190: 
 191:     try
 192:     {
 193:       if (resultset.last())
 194:       {
 195:         rowCount = resultset.getRow();
 196:         if (rowCount == -1)
 197:         {
 198:           rowCount = 0;
 199:         }
 200:       }
 201:       else
 202:       {
 203:         rowCount = 0;
 204:       }
 205:     }
 206:     catch (SQLException sqle)
 207:     {
 208:       //Log.debug ("GetRowCount failed, returning 0 rows", sqle);
 209:       return 0;
 210:     }
 211:     return rowCount;
 212:   }
 213: 
 214:   /**
 215:    * Returns the number of columns in the ResultSet. Returns 0 if no result set is set or
 216:    * the column count could not be retrieved.
 217:    *
 218:    * @return the column count.
 219:    *
 220:    * @see java.sql.ResultSetMetaData#getColumnCount()
 221:    */
 222:   public int getColumnCount ()
 223:   {
 224:     if (resultset == null)
 225:     {
 226:       return 0;
 227:     }
 228: 
 229:     if (dbmd != null)
 230:     {
 231:       try
 232:       {
 233:         return dbmd.getColumnCount();
 234:       }
 235:       catch (SQLException e)
 236:       {
 237:         //Log.debug ("GetColumnCount failed", e);
 238:       }
 239:     }
 240:     return 0;
 241:   }
 242: 
 243:   /**
 244:    * Returns the columnLabel or column name for the given column. Whether the label or the
 245:    * name is returned depends on the label map mode.
 246:    *
 247:    * @param column the column index.
 248:    * @return the column name.
 249:    *
 250:    * @see java.sql.ResultSetMetaData#getColumnLabel(int)
 251:    */
 252:   public String getColumnName (final int column)
 253:   {
 254:     if (dbmd != null)
 255:     {
 256:       try
 257:       {
 258:         if (isLabelMapMode())
 259:         {
 260:           return dbmd.getColumnLabel(column + 1);
 261:         }
 262:         else
 263:         {
 264:           return dbmd.getColumnName(column + 1);
 265:         }
 266:       }
 267:       catch (SQLException e)
 268:       {
 269:         Log.info("ScrollableResultSetTableModel.getColumnName: SQLException.");
 270:       }
 271:     }
 272:     return null;
 273:   }
 274: 
 275:   /**
 276:    * Returns the value of the specified row and the specified column from within the
 277:    * resultset.
 278:    *
 279:    * @param row    the row index.
 280:    * @param column the column index.
 281:    * @return the value.
 282:    */
 283:   public Object getValueAt (final int row, final int column)
 284:   {
 285:     if (resultset != null)
 286:     {
 287:       try
 288:       {
 289:         resultset.absolute(row + 1);
 290:         return resultset.getObject(column + 1);
 291:       }
 292:       catch (SQLException e)
 293:       {
 294:         //Log.debug ("Query failed for [" + row + "," + column + "]", e);
 295:       }
 296:     }
 297:     return null;
 298:   }
 299: 
 300:   /**
 301:    * Returns the class of the resultset column. Returns Object.class if an error
 302:    * occurred.
 303:    *
 304:    * @param column the column index.
 305:    * @return the column class.
 306:    */
 307:   public Class getColumnClass (final int column)
 308:   {
 309:     if (types != null)
 310:     {
 311:       return types[column];
 312:     }
 313:     if (dbmd != null)
 314:     {
 315:       try
 316:       {
 317:         types = TypeMapper.mapTypes(dbmd);
 318:         return types[column];
 319:       }
 320:       catch (Exception e)
 321:       {
 322:         //Log.debug ("GetColumnClass failed for " + column, e);
 323:       }
 324:     }
 325:     return Object.class;
 326:   }
 327: 
 328: 
 329:   /**
 330:    * Returns the classname of the resultset column. Returns Object.class if an error
 331:    * occurred.
 332:    *
 333:    * @param column the column index.
 334:    * @return the column class name.
 335:    */
 336:   public String getColumnClassName (final int column)
 337:   {
 338:     if (dbmd != null)
 339:     {
 340:       return mckoiDBFixClassName(getColumnClass(column).getName());
 341:     }
 342:     return Object.class.getName();
 343:   }
 344: 
 345:   /**
 346:    * Just removes the word class from the start of the classname string McKoiDB version
 347:    * 0.92 was not able to properly return classnames of resultset elements.
 348:    *
 349:    * @param classname the class name.
 350:    * @return the modified class name.
 351:    */
 352:   private String mckoiDBFixClassName (final String classname)
 353:   {
 354:     if (classname.startsWith("class "))
 355:     {
 356:       return classname.substring(6).trim();
 357:     }
 358:     return classname;
 359:   }
 360: }