/**
* 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.
*/
/**
* Operations on {@link java.lang.String} that are
* null safe.
*
* @see java.lang.String
* @author Apache Jakarta Turbine
* @author Jon S. Stevens
* @author Daniel L. Rall
* @author Greg Coladonato
* @author Ed Korthof
* @author Rand McNeely
* @author Stephen Colebourne
* @author Fredrik Westermarck
* @author Holger Krauth
* @author Alexander Day Chaffee
* @author Henning P. Schmiedehausen
* @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 {
/**
* Finds the last index within a String from a start position,
* handling null.
* This method uses {@link String#lastIndexOf(int, int)}.
*
* A null or empty ("") String will return -1.
* A negative start position returns -1.
* A start position greater than the string length searches the whole string.
*
*
* StringUtils.lastIndexOf(null, *, *) = -1
* StringUtils.lastIndexOf("", *, *) = -1
* StringUtils.lastIndexOf("aabaabaa", 'b', 8) = 5
* StringUtils.lastIndexOf("aabaabaa", 'b', 4) = 2
* StringUtils.lastIndexOf("aabaabaa", 'b', 0) = -1
* StringUtils.lastIndexOf("aabaabaa", 'b', 9) = 5
* StringUtils.lastIndexOf("aabaabaa", 'b', -1) = -1
* StringUtils.lastIndexOf("aabaabaa", 'a', 0) = 0
*
*
* @param str the String to check, may be null
* @param searchChar the character to find
* @param startPos the start position
* @return the last index of the search character,
* -1 if no match or null string input
* @since 2.0
*/
public static int lastIndexOf(String str, char searchChar, int startPos) {
if (isEmpty(str)) {
return -1;
}
return str.lastIndexOf(searchChar, startPos);
}
// Empty checks
//-----------------------------------------------------------------------
/**
* Checks if a String is empty ("") or null.
*
*
* StringUtils.isEmpty(null) = true
* StringUtils.isEmpty("") = true
* StringUtils.isEmpty(" ") = false
* StringUtils.isEmpty("bob") = false
* StringUtils.isEmpty(" bob ") = false
*
*
* NOTE: This method changed in Lang version 2.0.
* It no longer trims the String.
* That functionality is available in isBlank().
*
* @param str the String to check, may be null
* @return true if the String is empty or null
*/
public static boolean isEmpty(String str) {
return str == null || str.length() == 0;
}
}