tablerow.java

dspace 用j2ee架构的一个数字图书馆.开源程序

/*
 * TableRow.java
 *
 * Version: $Revision: 1.10 $
 *
 * Date: $Date: 2005/04/20 14:22:42 $
 *
 * Copyright (c) 2002-2005, Hewlett-Packard Company and Massachusetts
 * Institute of Technology.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the Hewlett-Packard Company nor the name of the
 * Massachusetts Institute of Technology nor the names of their
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */
package org.dspace.storage.rdbms;

import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.dspace.core.ConfigurationManager;

/**
 * Represents a database row.
 * 
 * @author Peter Breton
 * @version $Revision: 1.10 $
 */
public class TableRow
{
    /** Marker object to indicate NULLs. */
    private static final Object NULL_OBJECT = new Object();

    /** The name of the database table containing this row */
    private String table;

    /**
     * A map of column names to column values. The key of the map is a String,
     * the column name; the value is an Object, either an Integer, Boolean,
     * Date, or String. If the value is NULL_OBJECT, then the column was NULL.
     */
    private Map data = new HashMap();

    /**
     * Constructor
     * 
     * @param table
     *            The name of the database table containing this row.
     * @param columns
     *            A list of column names. Each member of the List is a String.
     *            After construction, the list of columns is fixed; attempting
     *            to access a column not in the list will cause an
     *            IllegalArgumentException to be thrown.
     */
    public TableRow(String table, List columns)
    {
        this.table = table;
        nullColumns(columns);
    }

    /**
     * Return the name of the table containing this row, or null if this row is
     * not associated with a database table.
     * 
     * @return The name of the table containing this row
     */
    public String getTable()
    {
        return table;
    }

    /**
     * Return true if this row contains a column with this name.
     * 
     * @param column
     *            The column name (case-insensitive)
     * @return True if this row contains a column with this name.
     */
    public boolean hasColumn(String column)
    {
        return data.get(canonicalize(column)) != null;
    }

    /**
     * Return true if the column is an SQL NULL.
     * 
     * @param column
     *            The column name (case-insensitive)
     * @return True if the column is an SQL NULL
     */
    public boolean isColumnNull(String column)
    {
        if (!hasColumn(column))
        {
            throw new IllegalArgumentException("No such column " + column);
        }

        return data.get(canonicalize(column)) == NULL_OBJECT;
    }

    /**
     * Return the integer value of column.
     * 
     * If the column's type is not an integer, or the column does not exist, an
     * IllegalArgumentException is thrown.
     * 
     * @param column
     *            The column name (case-insensitive)
     * @return The integer value of the column, or -1 if the column is an SQL
     *         null.
     */
    public int getIntColumn(String column)
    {
        if (!hasColumn(column))
        {
            throw new IllegalArgumentException("No such column " + column);
        }

        String name = canonicalize(column);

        if (isColumnNull(name))
        {
            return -1;
        }

        Object value = data.get(name);

        if (value == null)
        {
            throw new IllegalArgumentException("Column " + column
                    + " not present");
        }

        if (!(value instanceof Integer))
        {
            throw new IllegalArgumentException("Value for " + column
                    + " is not an integer");
        }

        return ((Integer) value).intValue();
    }

    /**
     * Return the long value of column.
     * 
     * If the column's type is not an long, or the column does not exist, an
     * IllegalArgumentException is thrown.
     * 
     * @param column
     *            The column name (case-insensitive)
     * @return The long value of the column, or -1 if the column is an SQL null.
     */
    public long getLongColumn(String column)
    {
        if (!hasColumn(column))
        {
            throw new IllegalArgumentException("No such column " + column);
        }

        String name = canonicalize(column);

        if (isColumnNull(name))
        {
            return -1;
        }

        Object value = data.get(name);

        if (value == null)
        {
            throw new IllegalArgumentException("Column " + column
                    + " not present");
        }

        if (!(value instanceof Long))
        {
            throw new IllegalArgumentException("Value is not an long");
        }

        return ((Long) value).longValue();
    }

    /**
     * Return the String value of column.
     * 
     * If the column's type is not a String, or the column does not exist, an
     * IllegalArgumentException is thrown.
     * 
     * @param column
     *            The column name (case-insensitive)
     * @return The String value of the column, or null if the column is an SQL
     *         null.
     */
    public String getStringColumn(String column)
    {
        if (!hasColumn(column))
        {
            throw new IllegalArgumentException("No such column " + column);
        }

        String name = canonicalize(column);

        if (isColumnNull(name))
        {
            return null;
        }

        Object value = data.get(name);

        if (value == null)
        {
            throw new IllegalArgumentException("Column " + column
                    + " not present");
        }

        if (!(value instanceof String))
        {
            throw new IllegalArgumentException("Value is not an string");
        }

        return (String) value;
    }

    /**
     * Return the boolean value of column.
     * 
     * If the column's type is not a boolean, or the column does not exist, an
     * IllegalArgumentException is thrown.
     * 
     * @param column
     *            The column name (case-insensitive)
     * @return The boolean value of the column, or false if the column is an SQL
     *         null.
     */
    public boolean getBooleanColumn(String column)
    {
        if (!hasColumn(column))
        {
            throw new IllegalArgumentException("No such column " + column);
        }

        String name = canonicalize(column);

        if (isColumnNull(name))
        {
            return false;
        }

        Object value = data.get(name);

        // make sure that we tolerate integers or booleans
        if (value == null)
        {
            throw new IllegalArgumentException("Column " + column
                    + " not present");
        }

        if ((value instanceof Boolean))
        {
            return ((Boolean) value).booleanValue();
        }
        else if ((value instanceof Integer))
        {