Mega Code Archive
Checks if the String contains only certain characters
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/**
* 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.
*/
/**
* <p>Operations on {@link java.lang.String} that are
* <code>null</code> safe.</p>
*
* @see java.lang.String
* @author <a href="http://jakarta.apache.org/turbine/">Apache Jakarta Turbine</a>
* @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
* @author Daniel L. Rall
* @author <a href="mailto:gcoladonato@yahoo.com">Greg Coladonato</a>
* @author <a href="mailto:ed@apache.org">Ed Korthof</a>
* @author <a href="mailto:rand_mcneely@yahoo.com">Rand McNeely</a>
* @author Stephen Colebourne
* @author <a href="mailto:fredrik@westermarck.com">Fredrik Westermarck</a>
* @author Holger Krauth
* @author <a href="mailto:alex@purpletech.com">Alexander Day Chaffee</a>
* @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
* @author Arun Mammen Thomas
* @author Gary Gregory
* @author Phil Steitz
* @author Al Chou
* @author Michael Davey
* @author Reuben Sivan
* @author Chris Hyzer
* @author Scott Johnson
* @since 1.0
* @version $Id: StringUtils.java 635447 2008-03-10 06:27:09Z bayard $
*/
public class Main {
/**
* <p>Checks if the String contains only certain characters.</p>
*
* <p>A <code>null</code> String will return <code>false</code>.
* A <code>null</code> valid character String will return <code>false</code>.
* An empty String ("") always returns <code>true</code>.</p>
*
* <pre>
* StringUtils.containsOnly(null, *) = false
* StringUtils.containsOnly(*, null) = false
* StringUtils.containsOnly("", *) = true
* StringUtils.containsOnly("ab", "") = false
* StringUtils.containsOnly("abab", "abc") = true
* StringUtils.containsOnly("ab1", "abc") = false
* StringUtils.containsOnly("abz", "abc") = false
* </pre>
*
* @param str the String to check, may be null
* @param validChars a String of valid chars, may be null
* @return true if it only contains valid chars and is non-null
* @since 2.0
*/
public static boolean containsOnly(String str, String validChars) {
if (str == null || validChars == null) {
return false;
}
return containsOnly(str, validChars.toCharArray());
}
// ContainsOnly
//-----------------------------------------------------------------------
/**
* <p>Checks if the String contains only certain characters.</p>
*
* <p>A <code>null</code> String will return <code>false</code>.
* A <code>null</code> valid character array will return <code>false</code>.
* An empty String ("") always returns <code>true</code>.</p>
*
* <pre>
* StringUtils.containsOnly(null, *) = false
* StringUtils.containsOnly(*, null) = false
* StringUtils.containsOnly("", *) = true
* StringUtils.containsOnly("ab", '') = false
* StringUtils.containsOnly("abab", 'abc') = true
* StringUtils.containsOnly("ab1", 'abc') = false
* StringUtils.containsOnly("abz", 'abc') = false
* </pre>
*
* @param str the String to check, may be null
* @param valid an array of valid chars, may be null
* @return true if it only contains valid chars and is non-null
*/
public static boolean containsOnly(String str, char[] valid) {
// All these pre-checks are to maintain API with an older version
if ((valid == null) || (str == null)) {
return false;
}
if (str.length() == 0) {
return true;
}
if (valid.length == 0) {
return false;
}
return indexOfAnyBut(str, valid) == -1;
}
// IndexOfAnyBut chars
//-----------------------------------------------------------------------
/**
* <p>Search a String to find the first index of any
* character not in the given set of characters.</p>
*
* <p>A <code>null</code> String will return <code>-1</code>.
* A <code>null</code> or zero length search array will return <code>-1</code>.</p>
*
* <pre>
* StringUtils.indexOfAnyBut(null, *) = -1
* StringUtils.indexOfAnyBut("", *) = -1
* StringUtils.indexOfAnyBut(*, null) = -1
* StringUtils.indexOfAnyBut(*, []) = -1
* StringUtils.indexOfAnyBut("zzabyycdxx",'za') = 3
* StringUtils.indexOfAnyBut("zzabyycdxx", '') = 0
* StringUtils.indexOfAnyBut("aba", 'ab') = -1
* </pre>
*
* @param str the String to check, may be null
* @param searchChars the chars to search for, may be null
* @return the index of any of the chars, -1 if no match or null input
* @since 2.0
*/
public static int indexOfAnyBut(String str, char[] searchChars) {
if (isEmpty(str) || isEmpty(searchChars)) {
return -1;
}
outer : for (int i = 0; i < str.length(); i++) {
char ch = str.charAt(i);
for (int j = 0; j < searchChars.length; j++) {
if (searchChars[j] == ch) {
continue outer;
}
}
return i;
}
return -1;
}
// ----------------------------------------------------------------------
/**
* <p>Checks if an array of Objects is empty or <code>null</code>.</p>
*
* @param array the array to test
* @return <code>true</code> if the array is empty or <code>null</code>
* @since 2.1
*/
public static boolean isEmpty(char[] array) {
if (array == null || array.length == 0) {
return true;
}
return false;
}
// Empty checks
//-----------------------------------------------------------------------
/**
* <p>Checks if a String is empty ("") or null.</p>
*
* <pre>
* StringUtils.isEmpty(null) = true
* StringUtils.isEmpty("") = true
* StringUtils.isEmpty(" ") = false
* StringUtils.isEmpty("bob") = false
* StringUtils.isEmpty(" bob ") = false
* </pre>
*
* <p>NOTE: This method changed in Lang version 2.0.
* It no longer trims the String.
* That functionality is available in isBlank().</p>
*
* @param str the String to check, may be null
* @return <code>true</code> if the String is empty or null
*/
public static boolean isEmpty(String str) {
return str == null || str.length() == 0;
}
}
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