Finds the n-th index within a String, handling null. : String search « Data Type « Java

1. Java
2. Data Type
3. String search

Finds the n-th index within a String, handling null.

      


/**
 * 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>Finds the n-th index within a String, handling <code>null</code>.
   * This method uses {@link String#indexOf(String)}.</p>
   *
   * <p>A <code>null</code> String will return <code>-1</code>.</p>
   *
   * <pre>
   * StringUtils.ordinalIndexOf(null, *, *)          = -1
   * StringUtils.ordinalIndexOf(*, null, *)          = -1
   * StringUtils.ordinalIndexOf("", "", *)           = 0
   * StringUtils.ordinalIndexOf("aabaabaa", "a", 1)  = 0
   * StringUtils.ordinalIndexOf("aabaabaa", "a", 2)  = 1
   * StringUtils.ordinalIndexOf("aabaabaa", "b", 1)  = 2
   * StringUtils.ordinalIndexOf("aabaabaa", "b", 2)  = 5
   * StringUtils.ordinalIndexOf("aabaabaa", "ab", 1) = 1
   * StringUtils.ordinalIndexOf("aabaabaa", "ab", 2) = 4
   * StringUtils.ordinalIndexOf("aabaabaa", "", 1)   = 0
   * StringUtils.ordinalIndexOf("aabaabaa", "", 2)   = 0
   * </pre>
   *
   * @param str  the String to check, may be null
   * @param searchStr  the String to find, may be null
   * @param ordinal  the n-th <code>searchStr</code> to find
   * @return the n-th index of the search String,
   *  <code>-1</code> (<code>INDEX_NOT_FOUND</code>) if no match or <code>null</code> string input
   * @since 2.1
   */
  public static int ordinalIndexOf(String str, String searchStr, int ordinal) {
      if (str == null || searchStr == null || ordinal <= 0) {
          return -1;
      }
      if (searchStr.length() == 0) {
          return 0;
      }
      int found = 0;
      int index = -1;
      do {
          index = str.indexOf(searchStr, index + 1);
          if (index < 0) {
              return index;
          }
          found++;
      } while (found < ordinal);
      return index;
  }


}

   
    
    
    
    
    
  

Related examples in the same category

1.	String Region Match Demo
2.	Palindrome
3.	Look for particular sequences in sentences
4.	Strings -- extract printable strings from binary file
5.	Java Search String
6.	Java String endsWith
7.	Java String startsWith
8.	Search a substring Anywhere
9.	Starts with, ignore case( regular expressions )
10.	Ends with, ignore case( regular expressions )
11.	Anywhere, ignore case( regular expressions )
12.	Searching a String for a Character or a Substring
13.	Not found returns -1
14.	If a string contains a specific word
15.	Not found
16.	if a String starts with a digit or uppercase letter
17.	Search a String to find the first index of any character in the given set of characters.
18.	Search a String to find the first index of any character not in the given set of characters.
19.	Searches a String for substrings delimited by a start and end tag, returning all matching substrings in an array.
20.	Helper functions to query a strings end portion. The comparison is case insensitive.
21.	Helper functions to query a strings start portion. The comparison is case insensitive.
22.	Wrapper for arrays of ordered strings. This verifies the arrays and supports efficient lookups.
23.	Returns an index into arra (or -1) where the character is not in the charset byte array.
24.	Returns an int[] array of length segments containing the distribution count of the elements in unsorted int[] array with values between min and max (range).
25.	Returns the next index of a character from the chars string
26.	Finds the first index within a String, handling null.
27.	Finds the last index within a String from a start position, handling null.
28.	Case insensitive check if a String ends with a specified suffix.
29.	Case insensitive check if a String starts with a specified prefix.
30.	Case insensitive removal of a substring if it is at the begining of a source string, otherwise returns the source string.
31.	Case insensitive removal of a substring if it is at the end of a source string, otherwise returns the source string.
32.	Check if a String ends with a specified suffix.
33.	Check if a String starts with a specified prefix.
34.	Determine if a String is contained in a String Collection
35.	Determine if a String is contained in a String Collection, ignoring case
36.	Determine if a String is contained in a String [], ignoring case
37.	Determine if a String is contained in a String [], ignoring case or not as specified
38.	Determine if a String is contained in a String[]
39.	Determines if the specified string contains only Unicode letters or digits as defined by Character#isLetterOrDigit(char)
40.	Determining the validity of various XML names
41.	Return the nth index of the given token occurring in the given string
42.	Find the earliest index of any of a set of potential substrings.
43.	Find the latest index of any of a set of potential substrings.
44.	Fast String Search
45.	Performs continuous matching of a pattern in a given string.
46.	Count match