Java Boolean From toBoolean(String str)

Description

Converts a String to a boolean (optimised for performance).

License

Open Source License

Parameter

Parameter	Description
str	the String to check

Return

the boolean value of the string, false if no match

Declaration

public static boolean toBoolean(String str) 

Method Source Code

//package com.java2s;
/*/* w w  w . j a  va 2 s .c  om*/
 * Metadata Editor
 * 
 * Metadata Editor - Rich internet application for editing metadata.
 * Copyright (C) 2011  Matous Jobanek (matous.jobanek@mzk.cz)
 * Moravian Library in Brno
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * 
 */

public class Main {
    /**
     * <p>
     * Converts a String to a boolean (optimised for performance).
     * </p>
     * <p>
     * <code>'true'</code>, <code>'on'</code> or <code>'yes'</code> (case
     * insensitive) will return <code>true</code>. Otherwise, <code>false</code>
     * is returned.
     * </p>
     * <p>
     * This method performs 4 times faster (JDK1.4) than
     * <code>Boolean.valueOf(String)</code>. However, this method accepts 'on'
     * and 'yes' as true values.
     * 
     * <pre>
     *   BooleanUtils.toBoolean(null)    = false
     *   BooleanUtils.toBoolean("true")  = true
     *   BooleanUtils.toBoolean("TRUE")  = true
     *   BooleanUtils.toBoolean("tRUe")  = true
     *   BooleanUtils.toBoolean("on")    = true
     *   BooleanUtils.toBoolean("yes")   = true
     *   BooleanUtils.toBoolean("false") = false
     *   BooleanUtils.toBoolean("x gti") = false
     * </pre>
     * 
     * @param str
     *        the String to check
     * @return the boolean value of the string, <code>false</code> if no match
     */
    public static boolean toBoolean(String str) {
        // Previously used equalsIgnoreCase, which was fast for interned 'true'.
        // Non interned 'true' matched 15 times slower.
        //
        // Optimisation provides same performance as before for interned 'true'.
        // Similar performance for null, 'false', and other strings not length
        // 2/3/4.
        // 'true'/'TRUE' match 4 times slower, 'tRUE'/'True' 7 times slower.
        if (str == "true") {
            return true;
        }
        if (str == null) {
            return false;
        }
        switch (str.length()) {
        case 2: {
            char ch0 = str.charAt(0);
            char ch1 = str.charAt(1);
            return (ch0 == 'o' || ch0 == 'O') && (ch1 == 'n' || ch1 == 'N');
        }
        case 3: {
            char ch = str.charAt(0);
            if (ch == 'y') {
                return (str.charAt(1) == 'e' || str.charAt(1) == 'E')
                        && (str.charAt(2) == 's' || str.charAt(2) == 'S');
            }
            if (ch == 'Y') {
                return (str.charAt(1) == 'E' || str.charAt(1) == 'e')
                        && (str.charAt(2) == 'S' || str.charAt(2) == 's');
            }
            return false;
        }
        case 4: {
            char ch = str.charAt(0);
            if (ch == 't') {
                return (str.charAt(1) == 'r' || str.charAt(1) == 'R')
                        && (str.charAt(2) == 'u' || str.charAt(2) == 'U')
                        && (str.charAt(3) == 'e' || str.charAt(3) == 'E');
            }
            if (ch == 'T') {
                return (str.charAt(1) == 'R' || str.charAt(1) == 'r')
                        && (str.charAt(2) == 'U' || str.charAt(2) == 'u')
                        && (str.charAt(3) == 'E' || str.charAt(3) == 'e');
            }
        }
        }
        return false;
    }
}

Related

1. toBoolean(String s)
2. toBoolean(String s)
3. toBoolean(String str)
4. toBoolean(String str)
5. toBoolean(String str)
6. toBoolean(String string)
7. toBoolean(String string)
8. toBoolean(String string, boolean defaultValue)
9. toBoolean(String text)