Java String index of any character in character set

//package com.demo2s;

public class Main {
  public static void main(String[] argv) throws Exception {
    String str = "demo2s.com";
    char[] searchChars = new char[] { 'd', 'e', 'm', 'o', '2', 's' };
    System.out.println(indexOfAny(str, searchChars));
  }/*from  ww w. j a va2  s.c  o  m*/

  /**
   * <p>
   * Search a String to find the first index of any character 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>
   * indexOfAny(null, *)                = -1
   * indexOfAny("", *)                  = -1
   * indexOfAny(*, null)                = -1
   * indexOfAny(*, [])                  = -1
   * indexOfAny("zzabyycdxx",['z','a']) = 0
   * indexOfAny("zzabyycdxx",['b','y']) = 3
   * indexOfAny("aba", ['z'])           = -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 indexOfAny(String str, char[] searchChars) {
    if (isEmpty(str) || isArrayEmpty(searchChars)) {
      return -1;
    }
    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) {
          return i;
        }
      }
    }
    return -1;
  }

  /**
   * <p>
   * Search a String to find the first index of any character in the given set of
   * characters.
   * </p>
   *
   * <p>
   * A <code>null</code> String will return <code>-1</code>. A <code>null</code>
   * search string will return <code>-1</code>.
   * </p>
   *
   * <pre>
   * indexOfAny(null, *)            = -1
   * indexOfAny("", *)              = -1
   * indexOfAny(*, null)            = -1
   * indexOfAny(*, "")              = -1
   * indexOfAny("zzabyycdxx", "za") = 0
   * indexOfAny("zzabyycdxx", "by") = 3
   * indexOfAny("aba","z")          = -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 indexOfAny(String str, String searchChars) {
    if (isEmpty(str) || isEmpty(searchChars)) {
      return -1;
    }
    return indexOfAny(str, searchChars.toCharArray());
  }

  /**
   * <p>
   * Find the first index of any of a set of potential substrings.
   * </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>. A <code>null</code>
   * search array entry will be ignored, but a search array containing "" will
   * return <code>0</code> if <code>str</code> is not null. This method uses
   * {@link String#indexOf(String)}.
   * </p>
   *
   * <pre>
   * indexOfAny(null, *)                     = -1
   * indexOfAny(*, null)                     = -1
   * indexOfAny(*, [])                       = -1
   * indexOfAny("zzabyycdxx", ["ab","cd"])   = 2
   * indexOfAny("zzabyycdxx", ["cd","ab"])   = 2
   * indexOfAny("zzabyycdxx", ["mn","op"])   = -1
   * indexOfAny("zzabyycdxx", ["zab","aby"]) = 1
   * indexOfAny("zzabyycdxx", [""])          = 0
   * indexOfAny("", [""])                    = 0
   * indexOfAny("", ["a"])                   = -1
   * </pre>
   *
   * @param str
   *          the String to check, may be null
   * @param searchStrs
   *          the Strings to search for, may be null
   * @return the first index of any of the searchStrs in str, -1 if no match
   */
  public static int indexOfAny(String str, String[] searchStrs) {
    if ((str == null) || (searchStrs == null)) {
      return -1;
    }
    int sz = searchStrs.length;

    // String's can't have a MAX_VALUEth index.
    int ret = Integer.MAX_VALUE;

    int tmp = 0;
    for (int i = 0; i < sz; i++) {
      String search = searchStrs[i];
      if (search == null) {
        continue;
      }
      tmp = str.indexOf(search);
      if (tmp == -1) {
        continue;
      }

      if (tmp < ret) {
        ret = tmp;
      }
    }

    return (ret == Integer.MAX_VALUE) ? -1 : ret;
  }

  /**
   * <p>
   * Checks if a String is empty ("") or null.
   * </p>
   *
   * <pre>
   * isEmpty(null)      = true
   * isEmpty("")        = true
   * isEmpty(" ")       = false
   * isEmpty("bob")     = false
   * 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;
  }

  /**
   * <p>
   * Checks if an array of primitive chars 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 isArrayEmpty(char[] array) {
    if (array == null || array.length == 0) {
      return true;
    }
    return false;
  }

}

/*
 * Licensed 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.
 */