compoundprimarykeycolumnspec.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.lang.reflect.Field;

import java.sql.SQLException;
import java.util.ArrayList;

import java.util.Iterator;
import java.util.List;
import java.util.StringTokenizer;

/**
 * This implementer of ColumnSpec holds multiple AbstractColumnSpec subclass
 * instances that make up the primary key for a table.
 */
public class CompoundPrimaryKeyColumnSpec
         implements ColumnSpec
{

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

    protected static Class         s_class = null;

    private List                   i_columnSpecs = new ArrayList();


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

    /**
     * Constructor for the CompoundPrimaryKeyColumnSpec object
     * use the method addColumnSpec(...) in conjunction with this.
     */
    public CompoundPrimaryKeyColumnSpec()
    {
    }

    /**
     * Constructor for the CompoundPrimaryKeyColumnSpec object
     *
     * @param columnOne  a ColumnSpec
     * @param columnTwo  a ColumnSpec
     */
    public CompoundPrimaryKeyColumnSpec(
            ColumnSpec columnOne,
            ColumnSpec columnTwo)
    {
        this.addColumnSpec(columnOne);
        this.addColumnSpec(columnTwo);
    }


    /**
     * Constructor for the CompoundPrimaryKeyColumnSpec object
     *
     * @param columnOne    a ColumnSpec
     * @param columnTwo    a ColumnSpec
     * @param columnThree  a ColumnSpec
     */
    public CompoundPrimaryKeyColumnSpec(
            ColumnSpec columnOne,
            ColumnSpec columnTwo,
            ColumnSpec columnThree)
    {
        this(columnOne, columnTwo);
        this.addColumnSpec(columnThree);
    }

    /**
     * Constructor for the CompoundPrimaryKeyColumnSpec object
     *
     * @param columnOne    a ColumnSpec
     * @param columnTwo    a ColumnSpec
     * @param columnThree  a ColumnSpec
     * @param columnFour   a ColumnSpec
     */
    public CompoundPrimaryKeyColumnSpec(ColumnSpec columnOne, ColumnSpec columnTwo, ColumnSpec columnThree, ColumnSpec columnFour)
    {
        this(columnOne, columnTwo, columnThree);
        this.addColumnSpec(columnFour);
    }

    /**
     * Constructor for the CompoundPrimaryKeyColumnSpec object
     *
     * @param columnOne    a ColumnSpec
     * @param columnTwo    a ColumnSpec
     * @param columnThree  a ColumnSpec
     * @param columnFour   a ColumnSpec
     * @param columnFive   a ColumnSpec
     */
    public CompoundPrimaryKeyColumnSpec(ColumnSpec columnOne, ColumnSpec columnTwo, ColumnSpec columnThree, ColumnSpec columnFour, ColumnSpec columnFive)
    {
        this(columnOne, columnTwo, columnThree, columnFour);
        this.addColumnSpec(columnFive);
    }

    /**
     * Constructor for the CompoundPrimaryKeyColumnSpec object
     *
     * @param columnOne    a ColumnSpec
     * @param columnTwo    a ColumnSpec
     * @param columnThree  a ColumnSpec
     * @param columnFour   a ColumnSpec
     * @param columnFive   a ColumnSpec
     * @param columnSix    a ColumnSpec
     */
    public CompoundPrimaryKeyColumnSpec(ColumnSpec columnOne, ColumnSpec columnTwo, ColumnSpec columnThree, ColumnSpec columnFour, ColumnSpec columnFive, ColumnSpec columnSix)
    {
        this(columnOne, columnTwo, columnThree, columnFour, columnFive);
        this.addColumnSpec(columnSix);
    }


    /**
     * Adds a feature to the ColumnSpec attribute of the
     * CompoundPrimaryKeyColumnSpec object
     *
     * @param aColumnSpec  The feature to be added to the ColumnSpec attribute
     */
    public void addColumnSpec(ColumnSpec aColumnSpec)
    {
        aColumnSpec.setRequired(true);
        i_columnSpecs.add(aColumnSpec);
    }


    /**
     * Ask each of my ColumnSpec instances to get the appropriate column from
     * the helper and stick it into the PersistentObject.
     *
     * @param helper            a value of type 'JDBCHelper'
     * @param aPO               a value of type 'PersistentObject'
     * @exception SQLException  if an error occurs
     */
    public void copyColumnValueToPersistentObject(JDBCHelper helper,
            PersistentObject aPO)
        throws SQLException
    {
        ColumnSpec spec = null;
        Iterator iterator = i_columnSpecs.iterator();
        while (iterator.hasNext())
        {
            spec = (ColumnSpec) iterator.next();
            spec.copyColumnValueToPersistentObject(helper, aPO);
        }
    }


    /**
     * Convert the attribute for this object to a String that can be unconverted
     * later by the decodeToPersistentObject(...) method. The result of this
     * method is not for use in SQL.
     *
     * @param aPO              a value of type 'PersistentObject'
     * @return                 Description of the Returned Value
     */
    public String encodeFromPersistentObject(PersistentObject aPO)
    {
        StringBuffer buffer = new StringBuffer();
        ColumnSpec spec = null;
        Iterator iterator = i_columnSpecs.iterator();
        while (iterator.hasNext())
        {
            spec = (ColumnSpec) iterator.next();
            buffer.append(spec.encodeFromPersistentObject(aPO));
            if (iterator.hasNext())
            {
                buffer.append("|");
            }
        }// while
        return buffer.toString();
    }// encodeFromPersistentObject(aPO)


    /**
     * The String parameter must have been encoded with the
     * encodeFromPersistentObject(...) method. This is used by
     * AbstractDomain.decodePrimaryKey(aString). Parse out the String into
     * tokens. Ask each columnspec to convert the string to the appropriate
     * object, then for each of my column specs, convert the given String into a
     * PersistentObject.
     *
     * @param aString  a value of type 'String'
     * @param aPO      a value of type 'PersistentObject'
     */
    public void decodeToPersistentObject(String aString,
            PersistentObject aPO)
    {
        StringTokenizer tokenizer = new StringTokenizer(aString, "|");
        Iterator iterator = i_columnSpecs.iterator();
        while (tokenizer.hasMoreTokens())
        {
            String token = tokenizer.nextToken();
            AbstractColumnSpec spec = (AbstractColumnSpec) iterator.next();
            spec.decodeToPersistentObject(token, aPO);
        }
    }// decodeToPersistentObject(aString, aPO)


    /**
     * This is an override of the method in ColumnSpec.
     *
     * @param aPO1  a value of type 'PersistentObject'
     * @param aPO2  a value of type 'PersistentObject'
     */
    public void copyAttribute(PersistentObject aPO1,
            PersistentObject aPO2)
    {
        ColumnSpec spec = null;
        Iterator iterator = i_columnSpecs.iterator();
        while (iterator.hasNext())
        {
            spec = (ColumnSpec) iterator.next();
            spec.copyAttribute(aPO1, aPO2);
        }
    }// copyAttribute(aPO, aPO)


    /**
     * Build a compound where clause (without the WHERE).
     *
     * @param aPO        a value of type 'PersistentObject'
     * @param separator  a value of type 'String'
     * @param tableName  a value of type 'String'
     * @param dbPolicy   a value of type 'DatabasePolicy'
     * @return           a value of type 'String'
     */
    public String buildWhereClause(Object aPO,
            String separator,
            String tableName,
            DatabasePolicy dbPolicy)
    {
        if (!(aPO instanceof PersistentObject))
        {
            throw new IllegalArgumentException(
                    "This primary key is compound.  Must pass in a PersistentObject "
                     + "with it's primary keys populated.");
        }
        ColumnSpec spec = null;
        Iterator iterator = i_columnSpecs.iterator();
        StringBuffer buffer = new StringBuffer();
        while (iterator.hasNext())
        {
            spec = (ColumnSpec) iterator.next();
            buffer.append(spec.buildNameValuePair(aPO,
                    separator,
                    tableName,
                    dbPolicy));
            if (iterator.hasNext())
            {
                buffer.append(" AND ");
            }
        }// for
        return buffer.toString();
    }// buildWhereClause(...)


    /**
     * Make sure the PersistentObject object has these attributes. All compound
     * primary key columns are required by definition.
     *
     * @param aPO                            a value of type 'PersistentObject'
     * @return                               Description of the Returned Value
     * @exception MissingAttributeException  if an error occurs
     */
    public Object validateRequired(PersistentObject aPO)
        throws MissingAttributeException
    {
        ColumnSpec spec = null;
        Iterator iterator = i_columnSpecs.iterator();
        while (iterator.hasNext())
        {
            spec = (ColumnSpec) iterator.next();
            spec.validateRequired(aPO);
        }
        return null;
    }// validateRequired(aPO)