integercolumnspec.java

把java对象映射成数据库表中的一条记录

/*
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at
 *
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations under
 * the License.
 *
 * The Original Code is jRelationalFramework.
 *
 * The Initial Developer of the Original Code is is.com.
 * Portions created by is.com are Copyright (C) 2000 is.com.
 * All Rights Reserved.
 *
 * Contributor(s): Jonathan Carlson ([e-mail])
 * Contributor(s): ____________________________________
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License (the "GPL") or the GNU Lesser General
 * Public license (the "LGPL"), in which case the provisions of the GPL or
 * LGPL are applicable instead of those above.  If you wish to allow use of
 * your version of this file only under the terms of either the GPL or LGPL
 * and not to allow others to use your version of this file under the MPL,
 * indicate your decision by deleting the provisions above and replace them
 * with the notice and other provisions required by either the GPL or LGPL
 * License.  If you do not delete the provisions above, a recipient may use
 * your version of this file under either the MPL or GPL or LGPL License.
 *
 */
package com.is.jrf;


import com.is.util.sql.JDBCHelper;

import java.sql.SQLException;


/**
 * This subclass of AbstractColumnSpec does Integer-specific things.
 */
public class IntegerColumnSpec
    extends AbstractColumnSpec
  {


  /* ===============  Static Variables  =============== */

  protected static final Class s_class = Integer.class;


  /* ===============  Constructors  =============== */

  public IntegerColumnSpec(
      String  columnName,
      String  getter,
      String  setter,
      Object  defaultValue)
    {
    super(columnName,
          getter,
          setter,
          (Integer) defaultValue);
    }

  public IntegerColumnSpec(
      String  columnName,
      String  getter,
      String  setter,
      Object  defaultValue,
      int     option1)
    {
    super(columnName,
          getter,
          setter,
          (Integer) defaultValue,
          option1);
    }

  public IntegerColumnSpec(
      String  columnName,
      String  getter,
      String  setter,
      Object  defaultValue,
      int     option1,
      int     option2)
    {
    super(columnName,
          getter,
          setter,
          (Integer) defaultValue,
          option1,
          option2);
    }

  public IntegerColumnSpec(
      String  columnName,
      String  getter,
      String  setter,
      Object  defaultValue,
      int     option1,
      int     option2,
      int     option3)
    {
    super(columnName,
          getter,
          setter,
          (Integer) defaultValue,
          option1,
          option2,
          option3);
    }


  /**
   * This method overrides the superclass implementation.
   *
   * @param obj a value of type 'Object'
   * @param dbPolicy a value of type 'DatabasePolicy'
   * @return a value of type 'String'
   */
  public String formatForSql(Object obj, DatabasePolicy dbPolicy)
    {
    Integer integer = (Integer)obj; // force a runtime error if not an Integer
    return (integer == null ? "null" : integer.toString());
    } // formatForSql(...)


  public Class getColumnClass()
    {
    return s_class;
    }


  /**
   * This ensures we get an Integer (instead of a BigInteger or something
   * else) from the JDBC driver.
   *
   * @param helper a value of type 'JDBCHelper'
   * @return a value of type 'Object'
   * @exception SQLException if an error occurs
   */
  public Object getColumnValueFrom(JDBCHelper helper)
          throws SQLException
    {
    return helper.getInteger(this.getColumnName());
    }


  /**
   * This method goes with encode().  The String parameter must have been
   * created by the encode() method.
   *
   * @param aString a value of type 'String'
   * @param aPO a value of type 'PersistentObject'
   */
  public Object decode(String aString)
    {
    Integer returnValue = null;
    if (aString.trim().equals("null"))
        {
        return null;
        }
    try
        {
        returnValue = Integer.valueOf(aString);
        }
    catch (NumberFormatException e)
        {
        throw new DatabaseException(
            "Invalid parameter to IntegerColumnSpec.getValueFrom(aString))");
        }
    return returnValue;
    }


  /**
   * Return the ANSI standard SQL column type.
   *
   * @param dbPolicy a value of type 'DatabasePolicy'
   * @return a value of type 'String'
   */
  public String getSQLColumnType(DatabasePolicy dbPolicy)
    {
    return "INTEGER";
    }


  /**
   * This is an override that converts Longs into Integers.  This is needed
   * for sequenced primary keys that are Integers.
   *
   * @param aValue a value of type 'Object'
   * @param aPO a value of type 'PersistentObject'
   */
  public void setValueTo(Object aValue,
                         PersistentObject aPO)
    {
    if (aValue instanceof Long)
        {
        Long aLong = (Long) aValue;
        aValue = new Integer(aLong.intValue());
        }
    super.setValueTo(aValue, aPO);
    }


  public Object optimisticLockDefaultValue()
    {
    return new Integer(0);
    }

  public JoinColumn buildJoinColumn()
    {
    return new IntegerJoinColumn(this.getColumnName(),
                                 this.getSetter());
    }


  } // IntegerColumnSpec