Operations on {@link java.lang.String} that are
* null
safe.
Find the first index of any of a set of potential substrings.
* *A null
String will return -1
.
* A null
or zero length search array will return -1
.
* A null
search array entry will be ignored, but a search
* array containing "" will return 0
if str
is not
* null. This method uses {@link String#indexOf(String)}.
* StringUtils.indexOfAny(null, *) = -1 * StringUtils.indexOfAny(*, null) = -1 * StringUtils.indexOfAny(*, []) = -1 * StringUtils.indexOfAny("zzabyycdxx", ["ab","cd"]) = 2 * StringUtils.indexOfAny("zzabyycdxx", ["cd","ab"]) = 2 * StringUtils.indexOfAny("zzabyycdxx", ["mn","op"]) = -1 * StringUtils.indexOfAny("zzabyycdxx", ["zab","aby"]) = 1 * StringUtils.indexOfAny("zzabyycdxx", [""]) = 0 * StringUtils.indexOfAny("", [""]) = 0 * StringUtils.indexOfAny("", ["a"]) = -1 ** * @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; } // ---------------------------------------------------------------------- /** *
Checks if an array of Objects is empty or null
.
true
if the array is empty or null
* @since 2.1
*/
public static boolean isEmpty(char[] array) {
if (array == null || array.length == 0) {
return true;
}
return false;
}
// 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 * @returntrue
if the String is empty or null
*/
public static boolean isEmpty(String str) {
return str == null || str.length() == 0;
}
}