Case insensitive check if a String starts with a specified prefix.
* *null
s are handled without exceptions. Two null
* references are considered to be equal. The comparison is case insensitive.
* StringUtils.startsWithIgnoreCase(null, null) = true * StringUtils.startsWithIgnoreCase(null, "abcdef") = false * StringUtils.startsWithIgnoreCase("abc", null) = false * StringUtils.startsWithIgnoreCase("abc", "abcdef") = true * StringUtils.startsWithIgnoreCase("abc", "ABCDEF") = true ** * @see java.lang.String#startsWith(String) * @param str the String to check, may be null * @param prefix the prefix to find, may be null * @return
true
if the String starts with the prefix, case insensitive, or
* both null
* @since 2.4
*/
public static boolean startsWithIgnoreCase(String str, String prefix) {
return startsWith(str, prefix, true);
}
/**
* Check if a String starts with a specified prefix (optionally case insensitive).
* * @see java.lang.String#startsWith(String) * @param str the String to check, may be null * @param prefix the prefix to find, may be null * @param ignoreCase inidicates whether the compare should ignore case * (case insensitive) or not. * @returntrue
if the String starts with the prefix or
* both null
*/
private static boolean startsWith(String str, String prefix, boolean ignoreCase) {
if (str == null || prefix == null) {
return (str == null && prefix == null);
}
if (prefix.length() > str.length()) {
return false;
}
return str.regionMatches(ignoreCase, 0, prefix, 0, prefix.length());
}
// 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;
}
}