Mega Code Archive
Fast lower case conversion
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//
// Copyright 2004-2005 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
//
/** Fast String Utilities.
*
* These string utilities provide both conveniance methods and
* performance improvements over most standard library versions. The
* main aim of the optimizations is to avoid object creation unless
* absolutely required.
*
* @author Greg Wilkins (gregw)
*/
class StringUtil
{
public static final String CRLF="\015\012";
public static final String __LINE_SEPARATOR=
System.getProperty("line.separator","\n");
public static String __ISO_8859_1;
static
{
String iso=System.getProperty("ISO_8859_1");
if (iso!=null)
__ISO_8859_1=iso;
else
{
try{
new String(new byte[]{(byte)20},"ISO-8859-1");
__ISO_8859_1="ISO-8859-1";
}
catch(java.io.UnsupportedEncodingException e)
{
__ISO_8859_1="ISO8859_1";
}
}
}
public final static String __UTF8="UTF-8";
private static char[] lowercases = {
'\000','\001','\002','\003','\004','\005','\006','\007',
'\010','\011','\012','\013','\014','\015','\016','\017',
'\020','\021','\022','\023','\024','\025','\026','\027',
'\030','\031','\032','\033','\034','\035','\036','\037',
'\040','\041','\042','\043','\044','\045','\046','\047',
'\050','\051','\052','\053','\054','\055','\056','\057',
'\060','\061','\062','\063','\064','\065','\066','\067',
'\070','\071','\072','\073','\074','\075','\076','\077',
'\100','\141','\142','\143','\144','\145','\146','\147',
'\150','\151','\152','\153','\154','\155','\156','\157',
'\160','\161','\162','\163','\164','\165','\166','\167',
'\170','\171','\172','\133','\134','\135','\136','\137',
'\140','\141','\142','\143','\144','\145','\146','\147',
'\150','\151','\152','\153','\154','\155','\156','\157',
'\160','\161','\162','\163','\164','\165','\166','\167',
'\170','\171','\172','\173','\174','\175','\176','\177' };
/* ------------------------------------------------------------ */
/**
* fast lower case conversion. Only works on ascii (not unicode)
* @param s the string to convert
* @return a lower case version of s
*/
public static String asciiToLowerCase(String s)
{
char[] c = null;
int i=s.length();
// look for first conversion
while (i-->0)
{
char c1=s.charAt(i);
if (c1<=127)
{
char c2=lowercases[c1];
if (c1!=c2)
{
c=s.toCharArray();
c[i]=c2;
break;
}
}
}
while (i-->0)
{
if(c[i]<=127)
c[i] = lowercases[c[i]];
}
return c==null?s:new String(c);
}
}
]]>