value.java

Town是一个100% 纯Java API

package com.workingdogs.town;

import java.sql.*;
import java.math.*;
import java.util.Calendar;

/*
Town, a Java JDBC abstraction layer
Copyright (C) 1999  Serge Knystautas, Jon S. Stevens

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.

This library 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
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA  02111-1307, USA.
*/
/**
A Value represents a single cell in a database table. In other words, it is the
cross between a row and column and contains the information held there.

@author Jon S. Stevens <A HREF="mailto:[e-mail]">[e-mail]</A>
@author Serge Knystautas <a href="mailto:[e-mail]">[e-mail]</a>
@version 1.0
*/
public class Value
{
    /** the object that is stored in this object */
    private Object valueObject;
    /** the column number that this object came from */
    private int columnNumber;
    /** what sql type of object is this? */
    private int type;
	
	private Value ()
	{
	}
	
    /**
     * Creates a new Value object based on the ResultSet, columnNumber and type
     *
     * @param   rs
     * @param   columnNumber
     * @param   type
     * @exception   ConnectionException
     */
    public Value (ResultSet rs, int columnNumber,
            int type) throws ConnectionException
    {
        this.columnNumber = columnNumber;
        this.type = type;
        this.valueObject = null;

        try
        {
            if (rs == null)
                return;

            switch (type())
            {
                case Types.BIT:
                    String tmp = rs.getString (columnNumber);
                    if (tmp == null)
                        valueObject = new Boolean (false);
                    else if (tmp.equalsIgnoreCase ("true") ||
                            tmp.equalsIgnoreCase ("yes") ||
                            tmp.equals ("1"))
                        valueObject = new Boolean (true);
                    else
                        valueObject = new Boolean (false);
                    break;

                case Types.TINYINT:
                    valueObject = new Byte (rs.getByte (columnNumber));
                    break;

                case Types.BIGINT:
                    valueObject = new Long (rs.getLong (columnNumber));
                    break;

                case Types.SMALLINT:
                    valueObject = new Short (rs.getShort (columnNumber));
                    break;

                case Types.INTEGER:
                    valueObject = new Integer (rs.getInt (columnNumber));
                    break;

                case Types.REAL:
                    valueObject = new Float (rs.getFloat (columnNumber));
                    break;

                case Types.FLOAT:
                case Types.DOUBLE:
                    valueObject = new Double (rs.getDouble (columnNumber));
                    break;

                case Types.NUMERIC:
                case Types.DECIMAL:
                    valueObject =
                            new BigDecimal (rs.getDouble (columnNumber));
                    break;

                case Types.LONGVARBINARY:
                case Types.VARBINARY:
                case Types.BINARY:
                    valueObject = rs.getBytes (columnNumber);
                    break;

                case Types.LONGVARCHAR:
                case Types.CHAR:
                case Types.VARCHAR:
                case Types.OTHER:
                    valueObject = rs.getString (columnNumber);
                    break;

                case Types.DATE:
                    valueObject = rs.getDate (columnNumber);
                    break;

                case Types.TIME:
                    valueObject = rs.getTime (columnNumber);
                    break;

                case Types.TIMESTAMP:
                    valueObject = rs.getTimestamp (columnNumber);
                    break;

                case Types.NULL:
                    valueObject = null;
                    break;

                default:
                    valueObject = rs.getString (columnNumber);
                    break;
            }

        }
        catch (SQLException sqle)
        {
            throw new ConnectionException (sqle);
        }
        return;
    }
    /**
       * Get the value as a BigDecimal
       *
       * @return     a BigDecimal
       * @exception   DataSetException
       */
    public BigDecimal asBigDecimal() throws DataSetException
    {
        try
        {
            if (isNull())
                return null;
            else if (isBigDecimal())
                return (BigDecimal) valueObject;
            else if (isString() || isDouble() || isFloat() || isInt() ||
                    isLong())
                return new BigDecimal (asString());
            else
                return null;
        }
        catch (Exception e)
        {
            throw new DataSetException("Illegal conversion: " +
                    e.toString());
        }
    }
    /**
       * Get the value as a BigDecimal
       *
       * @return     a BigDecimal
       * @exception   DataSetException
       */
    public BigDecimal asBigDecimal(int scale) throws DataSetException
    {
        try
        {
            if (isNull())
                return null;
            else if (isBigDecimal())
                return ((BigDecimal) valueObject).setScale (scale);
            else if (isString() || isDouble() || isFloat() || isInt() ||
                    isLong())
                return new BigDecimal (asString()).setScale (scale);
            else
                return null;
        }
        catch (Exception e)
        {
            throw new DataSetException("Bad conversion: " + e.toString());
        }
    }
    /**
       * Get the value as a asBoolean
       *
       * @return     a boolean
       * @exception   DataSetException
       */
    public boolean asBoolean() throws DataSetException
    {
        try
        {
            if (isNull())
                return false;
            else if (isBoolean())
                return ((Boolean) valueObject).booleanValue();

            String check = asString();
            if (check == null)
                return false;
            else if (check.equalsIgnoreCase ("yes") ||
                    check.equalsIgnoreCase ("true") || check.equals ("1"))
                return true;
            else
                return false;
        }
        catch (Exception e)
        {
            throw new DataSetException("Bad conversion: " + e.toString());
        }
    }
    /**
       * Get the value as a asByte
       *
       * @return     a byte
       * @exception   DataSetException
       */
    public byte asByte() throws DataSetException
    {
        try
        {
            if (isNull())
                return 0;
            else if (isByte())
                return ((Byte) valueObject).byteValue();
            else if (isString())
                return Integer.valueOf((String) valueObject).byteValue();
            else if (isShort())
                return ((Short) valueObject).byteValue();
            else if (isInt())
                return ((Integer) valueObject).byteValue();
            else if (isLong())
                return ((Long) valueObject).byteValue();
            else if (isDouble())
                return ((Double) valueObject).byteValue();
            else if (isFloat())
                return ((Float) valueObject).byteValue();
            else if (isBigDecimal())
                return ((BigDecimal) valueObject).byteValue();
            else
                return Integer.valueOf(asString()).byteValue();
        }
        catch (Exception e)
        {
            throw new DataSetException("Bad conversion: " + e.toString());
        }
    }
    /**
       * Get the value as a asBytes
       *
       * @return     a byte array
       * @exception   DataSetException
       */
    public byte[] asBytes() throws DataSetException
    {
        try
        {
            if (isNull())
                return null;
            else if (isBytes())
                return (byte[]) valueObject;
            else if (isString())
                return ((String) valueObject).getBytes();
        }
        catch (Exception e)
        {
            throw new DataSetException("Bad conversion: " + e.toString());
        }
        return null;
    }
    /**
       * Get the value as a asDate
       *
       * @return     a java.sql.Date
       * @exception   DataSetException
       */
    public java.sql.Date asDate() throws DataSetException
    {
        try
        {
            if (isNull())
                return null;
            else if (isDate())
                return (java.sql.Date) valueObject;

            Calendar cal = Calendar.getInstance();
            if (isTimestamp())
            {
                cal.setTime ((Timestamp) valueObject);
                return java.sql.Date.valueOf (cal.get(Calendar.YEAR) +
                        "-" + (cal.get(Calendar.MONTH) + 1) + "-" +
                        cal.get(Calendar.DAY_OF_MONTH));
            }
            else if (isTime())
            {
                cal.setTime ((Time) valueObject);
                return java.sql.Date.valueOf (cal.get(Calendar.YEAR) +
                        "-" + (cal.get(Calendar.MONTH) + 1) + "-" +
                        cal.get(Calendar.DAY_OF_MONTH));
            }
            else if (isUtilDate())
            {
                cal.setTime ((java.util.Date) valueObject);
                return java.sql.Date.valueOf (cal.get(Calendar.YEAR) +
                        "-" + (cal.get(Calendar.MONTH) + 1) + "-" +
                        cal.get(Calendar.DAY_OF_MONTH));
            }
            else if (isString())
                return java.sql.Date.valueOf((String) valueObject);
            else
                return java.sql.Date.valueOf(asString());
        }
        catch (IllegalArgumentException a)
        {
            throw new DataSetException("Bad date value - Java Timestamp Objects cannot be earlier than 1/1/70");
        }
        catch (Exception b)
        {
            throw new DataSetException("Bad conversion: " + b.toString());
        }
    }
    /**
       * Get the value as a asDouble
       *
       * @return     a double
       * @exception   DataSetException
       */
    public double asDouble() throws DataSetException
    {
        try
        {
            if (isNull())
                return 0.0D;
            else if (isDouble())
                return ((Double) valueObject).doubleValue();
            else if (isString())
                return Integer.valueOf((String) valueObject).doubleValue();
            else if (isShort())
                return ((Short) valueObject).doubleValue();
            else if (isInt())
                return ((Integer) valueObject).doubleValue();
            else if (isLong())
                return ((Long) valueObject).doubleValue();
            else if (isFloat())
                return ((Float) valueObject).doubleValue();
            else if (isBigDecimal())
                return ((BigDecimal) valueObject).doubleValue();
            else
                return Integer.valueOf(asString()).doubleValue();
        }
        catch (Exception e)
        {
            throw new DataSetException("Bad conversion: " + e.toString());
        }
    }
    /**
       * Get the value as a asFloat
       *
       * @return     a float
       * @exception   DataSetException
       */
    public float asFloat() throws DataSetException
    {
        try
        {
            if (isNull())
                return 0.0F;
            else if (isFloat())
                return ((Float) valueObject).floatValue();
            else if (isString())
                return Integer.valueOf((String) valueObject).floatValue();
            else if (isShort())
                return ((Short) valueObject).floatValue();
            else if (isInt())
                return ((Integer) valueObject).floatValue();
            else if (isLong())
                return ((Long) valueObject).floatValue();
            else if (isDouble())
                return ((Double) valueObject).floatValue();
            else if (isBigDecimal())
                return ((BigDecimal) valueObject).floatValue();
            else
                return Integer.valueOf(asString()).floatValue();
        }
        catch (Exception e)
        {
            throw new DataSetException("Bad conversion: " + e.toString());
        }
    }
    /**
       * Get the value as a asInt
       *
       * @return     an int
       * @exception   DataSetException
       */
    public int asInt() throws DataSetException
    {
        try
        {
            if (isNull())
                return 0;
            else if (isInt())
                return ((Integer) valueObject).intValue();
            else if (isString())
                return Integer.valueOf((String) valueObject).intValue();
            else if (isLong())
                return ((Long) valueObject).intValue();
            else if (isDouble())
                return ((Double) valueObject).intValue();
            else if (isFloat())
                return ((Float) valueObject).intValue();
            else if (isBigDecimal())
                return ((BigDecimal) valueObject).intValue();
            else
                return Integer.valueOf(asString()).intValue();
        }
        catch (Exception e)
        {
            throw new DataSetException("Bad conversion: " + e.toString());
        }
    }
    /**
       * Get the value as a asLong
       *
       * @return     a long
       * @exception   DataSetException
       */
    public long asLong() throws DataSetException
    {
        try
        {
            if (isNull())
                return 0;
            else if (isLong())
                return ((Long) valueObject).longValue();
            else if (isString())
                return Integer.valueOf((String) valueObject).longValue();
            else if (isShort())
                return ((Short) valueObject).longValue();
            else if (isInt())
                return ((Integer) valueObject).longValue();
            else if (isDouble())
                return ((Double) valueObject).longValue();
            else if (isFloat())
                return ((Float) valueObject).longValue();
            else if (isBigDecimal())
                return ((BigDecimal) valueObject).longValue();
            else
                return Integer.valueOf(asString()).longValue();
        }