SQLMetaData.java

/*
 * This program is free software; you can redistribute it and/or modify it under the 
 * terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software 
 * Foundation.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this 
 * program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html 
 * or from the Free Software Foundation, Inc., 
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; 
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * Copyright 2005 - 2009 Pentaho Corporation.  All rights reserved.
 *
 *
 * Created Sep 7, 2005 
 * @author wseyler
 */

package org.pentaho.platform.plugin.services.connections.sql;

import java.sql.ResultSetMetaData;
import java.sql.SQLException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.pentaho.commons.connection.AbstractPentahoMetaData;

/**
 * @author wseyler
 * 
 * TODO To change the template for this generated type comment go to Window -
 * Preferences - Java - Code Style - Code Templates
 */
public class SQLMetaData extends AbstractPentahoMetaData {

  protected static final Log logger = LogFactory.getLog(SQLMetaData.class);

  ResultSetMetaData nativeMetaData = null;

  private Object[][] columnHeaders;

  public SQLMetaData(final ResultSetMetaData nativeMetaData) {
    this.nativeMetaData = nativeMetaData;
  }

  public int[] getJDBCColumnTypes() throws SQLException {
    if ( nativeMetaData != null) {
      int colCount = nativeMetaData.getColumnCount();
      if (colCount > 0) {
        int[] rtn = new int[colCount];
        for (int i=0; i< colCount; i++) {
          rtn[i] = nativeMetaData.getColumnType(i+1); // JDBC is 1-based
        }
        return rtn;
      } else {
        return new int[]{};
      }
    } else {
      throw new IllegalStateException();
    }
  }

  /*
   * (non-Javadoc)
   * 
   * @see org.pentaho.connection.IPentahoMetaData#getColumnHeaders()
   * 
   * In the case of SQL data there is only 1 row
   */
  @Override
  public Object[][] getColumnHeaders() {
    if (columnHeaders == null) {
      try {
        int rowCount = 1;
        int columnCount = nativeMetaData.getColumnCount();
        Object[][] result = new Object[rowCount][columnCount];
        for (int column = 0; column < columnCount; column++) {
          result[0][column] = nativeMetaData.getColumnLabel(column + 1);
        }
        this.columnHeaders = result;
      } catch (SQLException e) {
        SQLMetaData.logger.error(null, e);
      }
    }
    return columnHeaders;
  }

  @Override
  public int getColumnCount() {
    try {
      return nativeMetaData.getColumnCount();
    } catch (SQLException ex) {
      SQLMetaData.logger.error(null, ex);
    }
    // TODO: Ripple the exception out of this package
    return -1;
  }

  @Override
  public Object[][] getRowHeaders() {
    return null;
  }
}