Checks if the CharSequence contains only whitespace - Android java.lang

Android examples for java.lang:String

Description

Checks if the CharSequence contains only whitespace

Demo Code

/*//from w  w  w.j a v  a  2  s .  c  o  m
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */
 
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.text.Normalizer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.regex.Pattern;

public class Main{

    /**
     * <p>Checks if the CharSequence contains only whitespace.</p>
     *
     * <p>{@code null} will return {@code false}.
     * An empty CharSequence (length()=0) will return {@code true}.</p>
     *
     * <pre>
     * StringUtils.isWhitespace(null)   = false
     * StringUtils.isWhitespace("")     = true
     * StringUtils.isWhitespace("  ")   = true
     * StringUtils.isWhitespace("abc")  = false
     * StringUtils.isWhitespace("ab2c") = false
     * StringUtils.isWhitespace("ab-c") = false
     * </pre>
     *
     * @param cs  the CharSequence to check, may be null
     * @return {@code true} if only contains whitespace, and is non-null
     * @since 2.0
     * @since 3.0 Changed signature from isWhitespace(String) to isWhitespace(CharSequence)
     */
    public static boolean isWhitespace(final CharSequence cs) {
        if (cs == null) {
            return false;
        }
        final int sz = cs.length();
        for (int i = 0; i < sz; i++) {
            if (Character.isWhitespace(cs.charAt(i)) == false) {
                return false;
            }
        }
        return true;
    }

}

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