/*
* 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 .
*
* 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 the Venice Web Communities System.
*
* The Initial Developer of the Original Code is Eric J. Bowersox ,
* for Silverwrist Design Studios. Portions created by Eric J. Bowersox are
* Copyright (C) 2001 Eric J. Bowersox/Silverwrist Design Studios. All Rights Reserved.
*
* Contributor(s):
*/
package com.silverwrist.venice.db;
import java.sql.*;
import java.util.*;
import com.silverwrist.util.AnyCharMatcher;
import com.silverwrist.util.StringUtil;
/**
* Utility functions commonly used for passing string values to SQL commands, and interpreting the results.
*
* @author Eric J. Bowersox <erbo@silcom.com>
* @version X
* @see com.silverwrist.util.StringUtil
*/
public class SQLUtil
{
/*--------------------------------------------------------------------------------
* Static data members
*--------------------------------------------------------------------------------
*/
private static final String SQL_WILDCARD_CHARS = "%_'";
// used to convert dates and times to UTC for sending to SQL
private static SimpleTimeZone utc = new SimpleTimeZone(0,"UTC");
/*--------------------------------------------------------------------------------
* Internal functions
*--------------------------------------------------------------------------------
*/
/**
* Converts a date-and-time string (an SQL DATETIME value) to a standard Java date.
*
* @param dstr The date-and-time string to convert, presumed to be in UTC.
* @return The converted date and time.
* @exception java.sql.SQLException The date and time string was in an invalid format.
*/
private static java.util.Date convertDateTimeString(String dstr) throws SQLException
{
if (dstr==null)
return null; // null values are the same
try
{ // do almost the reverse process of formatting it into a string
GregorianCalendar cal = new GregorianCalendar(utc);
cal.set(Calendar.YEAR,Integer.parseInt(dstr.substring(0,4)));
cal.set(Calendar.MONTH,Integer.parseInt(dstr.substring(5,7)) - 1 + Calendar.JANUARY);
cal.set(Calendar.DAY_OF_MONTH,Integer.parseInt(dstr.substring(8,10)));
cal.set(Calendar.HOUR_OF_DAY,Integer.parseInt(dstr.substring(11,13)));
cal.set(Calendar.MINUTE,Integer.parseInt(dstr.substring(14,16)));
cal.set(Calendar.SECOND,Integer.parseInt(dstr.substring(17,19)));
return cal.getTime();
} // end try
catch (NumberFormatException e)
{ // the NumberFormatException becomes an SQLException
throw new SQLException("invalid DATETIME field format");
} // end catch
} // end convertDateString
/*--------------------------------------------------------------------------------
* External static operations
*--------------------------------------------------------------------------------
*/
/**
* Performs SQL encoding of an arbitrary string. When a string is SQL-encoded, all single-quote
* characters are doubled, and all other characters are left untouched.
*
* @param str The string to be SQL-encoded. May be null.
* @return The SQL-encoded equivalent of str. If str is
* null, returns null.
* @see com.silverwrist.util.StringUtil#encodeStringSQL(java.lang.String)
*/
public static String encodeString(String str)
{
return StringUtil.encodeStringSQL(str);
} // end encodeString
/**
* Performs SQL encoding of an arbitrary string, enclosing it in quotes, so that it may be passed as an
* argument in an SQL statement. When a string is SQL-encoded, all single-quote characters are doubled,
* and all other characters are left untouched.
*
* @param str The string to be SQL-encoded. May be null.
* @return The SQL-encoded equivalent of str, in quotes. If str is
* null, returns "NULL".
* @see com.silverwrist.util.StringUtil#encodeStringSQL(java.lang.String)
*/
public static String encodeStringArg(String str)
{
if (str==null)
return "NULL";
StringBuffer b = new StringBuffer("'");
b.append(StringUtil.encodeStringSQL(str)).append('\'');
return b.toString();
} // end encodeStringArg
/**
* Performs SQL-encoding of a string which may contain the SQL wildcard characters, '%' and '_'. The
* wildcard characters are escaped with '\', and the single-quote characters are doubled, but all other
* characters are left untouched.
*
* @param str The string to be SQL-encoded. May be null.
* @return The SQL-encoded equivalent of str. If str is
* null, returns null.
*/
public static String encodeStringWildcards(String str)
{
if (str==null)
return null; // safety feature
AnyCharMatcher nhc = new AnyCharMatcher(SQL_WILDCARD_CHARS);
int ndx = nhc.get(str);
if (ndx<0)
return str; // trivial short-circuit case
StringBuffer buf = new StringBuffer();
while (ndx>=0)
{ // append the matched "head" and then the encoded character
if (ndx>0)
buf.append(str.substring(0,ndx));
switch (str.charAt(ndx++))
{
case '%':
buf.append("\\%");
break;
case '_':
buf.append("\\_");
break;
case '\'':
buf.append("\'\'");
break;
} // end switch
if (ndx==str.length())
return buf.toString(); // munched the entire string - all done!
str = str.substring(ndx);
ndx = nhc.get(str);
} // end while
buf.append(str); // append the unmatched tail
return buf.toString();
} // end encodeStringWildcards
/**
* Encodes a date as an SQL date/time string, expressed in UTC.
*
* @param d The date to be encoded.
* @return The string equivalent of that date.
*/
public static String encodeDate(java.util.Date d)
{
// Break down the date as a UTC value.
GregorianCalendar cal = new GregorianCalendar(utc);
cal.setTime(d);
// Create the two string buffers converting the date.
StringBuffer rc = new StringBuffer();
StringBuffer conv = new StringBuffer();
String c;
// Encode the year first.
conv.append("0000").append(cal.get(Calendar.YEAR));
c = conv.toString();
rc.append(c.substring(c.length()-4)).append('-');
// Now the month...
conv.setLength(0);
conv.append("00").append(cal.get(Calendar.MONTH) - Calendar.JANUARY + 1);
c = conv.toString();
rc.append(c.substring(c.length()-2)).append('-');
// And the day...
conv.setLength(0);
conv.append("00").append(cal.get(Calendar.DAY_OF_MONTH));
c = conv.toString();
rc.append(c.substring(c.length()-2)).append(' ');
// And the hour...
conv.setLength(0);
conv.append("00").append(cal.get(Calendar.HOUR_OF_DAY));
c = conv.toString();
rc.append(c.substring(c.length()-2)).append(':');
// And the minute...
conv.setLength(0);
conv.append("00").append(cal.get(Calendar.MINUTE));
c = conv.toString();
rc.append(c.substring(c.length()-2)).append(':');
// And the second...
conv.setLength(0);
conv.append("00").append(cal.get(Calendar.SECOND));
c = conv.toString();
rc.append(c.substring(c.length()-2));
// This is the resulting date/time value.
return rc.toString();
} // end encodeDate
/**
* Returns the value of a DATETIME column in the current row of an SQL result set, formatted as a date.
*
* @param rs The result set to look in.
* @param column The name of the column to be returned.
* @return The value of the specified column, expressed as a date.
* @exception java.sql.SQLException If the column could not be retrieved or converted.
*/
public static java.util.Date getFullDateTime(ResultSet rs, String column) throws SQLException
{
return convertDateTimeString(rs.getString(column));
} // end getFullDateTime
/**
* Returns the value of a DATETIME column in the current row of an SQL result set, formatted as a date.
*
* @param rs The result set to look in.
* @param column The 1-based index of the column to be returned.
* @return The value of the specified column, expressed as a date.
* @exception java.sql.SQLException If the column could not be retrieved or converted.
*/
public static java.util.Date getFullDateTime(ResultSet rs, int column) throws SQLException
{
return convertDateTimeString(rs.getString(column));
} // end getFullDateTime
} // end class SQLUtil