Java String Empty to Null emptyToNull(String s)

Description

empty To Null

License

Open Source License

Declaration

public static String emptyToNull(String s) 

Method Source Code

//package com.java2s;
/*//from w  ww . j a  v  a2  s . c o m
 * (c) Copyright 2007-2012 by Volker Bergmann. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, is permitted under the terms of the
 * GNU General Public License.
 *
 * For redistributing this software or a derivative work under a license other
 * than the GPL-compatible Free Software License as defined by the Free
 * Software Foundation or approved by OSI, you must first obtain a commercial
 * license to this software product from Volker Bergmann.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * WITHOUT A WARRANTY OF ANY KIND. ALL EXPRESS OR IMPLIED CONDITIONS,
 * REPRESENTATIONS AND WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE
 * HEREBY EXCLUDED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

public class Main {
    public static String emptyToNull(String s) {
        if (s == null || s.length() == 0)
            return null;
        String trimmed = trim(s);
        return (trimmed.length() != 0 ? s : null);
    }

    /** Trims a String by removing white spaces (including nbsp) from left and right. */
    public static String trim(String s) {
        if (s == null || s.length() == 0)
            return s;
        int beginIndex;
        for (beginIndex = 0; beginIndex < s.length() && isWhitespace(s.charAt(beginIndex)); beginIndex++) {
        }
        int endIndex;
        for (endIndex = s.length() - 1; endIndex > 0 && isWhitespace(s.charAt(endIndex)); endIndex--) {
        }
        if (beginIndex > endIndex)
            return "";
        return s.substring(beginIndex, endIndex + 1);
    }

    public static String trim(String source, char padChar) {
        if (source == null)
            return null;
        int i0 = 0;
        while (i0 < source.length() && source.charAt(i0) == padChar)
            i0++;
        if (i0 == source.length())
            return "";
        int i1 = source.length() - 1;
        while (i1 > i0 && source.charAt(i1) == padChar)
            i1--;
        return source.substring(i0, i1 + 1);
    }

    /** interprets an nbsp as space character */
    public static boolean isWhitespace(char c) {
        return Character.isWhitespace(c) || c == 160;
    }
}

Related

1. emptyStringToNull(String string)
2. emptyToDefault(String value, String def)
3. emptyToDefault(T[] values, T[] def)
4. emptyToNull(final String text, final boolean doTrim)
5. emptyToNull(String field)
6. emptyToNull(String s)
7. emptyToNull(String str)
8. emptyToNull(String str)
9. emptyToNull(String str)