Java Boolean From toBoolean(final String source)

Description

Returns true if the source string evaulates (case insensative and trimmed) to true, yes, or on.

License

Open Source License

Parameter

Parameter	Description
source	the string to check

Return

true if the source string evaulates to true or similar value, false otherwise.

Declaration

public static boolean toBoolean(final String source)

Method Source Code

//package com.java2s;
/*!/*from w w w. ja v a 2 s . c  o  m*/
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* 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 Lesser General Public License for more details.
*
* Copyright (c) 2002-2013 Pentaho Corporation..  All rights reserved.
*/

public class Main {
    private static final String TRUE = "true";
    private static final String YES = "yes";
    private static final String ON = "on";

    /**
     * Returns <code>true</code> if the source string evaulates (case insensative and trimmed) to <code>true</code>,
     * <code>yes</code>, or <code>on</code>. It will return <code>false</code> otherwise (including <code>null</code>).
     *
     * @param source the string to check
     * @return <code>true</code> if the source string evaulates to <code>true</code> or similar value, <code>false</code>
     * otherwise.
     */
    public static boolean toBoolean(final String source) {
        return toBoolean(source, false);
    }

    /**
     * Returns <code>true</code> if the source string evaulates (case insensative and trimmed) to <code>true</code>,
     * <code>yes</code>, or <code>on</code>. It will return <code>false otherwise. If the source string is
     * <code>null</code>, it will return the value of the default.
     *
     * @param source      the string to check
     * @param nullDefault to value to return if the source string is <code>null</code>
     * @return <code>true</code> if the source string evaulates to <code>true</code> or similar value, <code>false</code>
     * otherwise.
     */
    public static boolean toBoolean(String source, final boolean nullDefault) {
        // If the source is null, use the default
        if (source == null) {
            return nullDefault;
        }

        // Check for valid values
        source = source.trim().toLowerCase();
        return (TRUE.equals(source) || YES.equals(source) || ON.equals(source));
    }

    /**
     * Trims a string: removes the leading and trailing spaces of a String.
     *
     * @param str The string to trim
     * @return The trimmed string.
     */
    public static final String trim(String str) {
        if (str == null) {
            return null;
        }

        int max = str.length() - 1;
        int min = 0;

        while (min <= max && isSpace(str.charAt(min))) {
            min++;
        }
        while (max >= 0 && isSpace(str.charAt(max))) {
            max--;
        }

        if (max < min) {
            return "";
        }

        return str.substring(min, max + 1);
    }

    /**
     * Determines if the two Strings are equals (taking nulls into account).
     *
     * @param s1 the first string to compare.
     * @param s2 the second string to compare.
     * @return <code>true</code> if both string are null or the contain the same value, <code>false</code>otherwise
     */
    public static boolean equals(final String s1, final String s2) {
        return ((s1 == null && s2 == null) || (s1 != null && s1.equals(s2)));
    }

    /**
     * Determines whether or not a character is considered a space. A character is considered a space in Kettle if it is a
     * space, a tab, a newline or a cariage return.
     *
     * @param c The character to verify if it is a space.
     * @return true if the character is a space. false otherwise.
     */
    public static final boolean isSpace(char c) {
        return c == ' ' || c == '\t' || c == '\r' || c == '\n' || Character.isWhitespace(c);
    }
}