public static boolean equalsIgnoreCase(String str1, String str2) {
        return str1 == null ? str2 == null : str1.equalsIgnoreCase(str2);
    }
public static boolean equalsIgnoreCase ( String str1 , String str2 ) { return str1 == null ? str2 == null : str1 . equalsIgnoreCase ( str2 ) ; }
<p>Compares two Strings, returning <code>true</code> if they are equal ignoring
the case.</p>
<p><code>null</code>s are handled without exceptions. Two <code>null</code>
references are considered equal. Comparison is case insensitive.</p>

<pre>
StringUtils.equalsIgnoreCase(null, null)   = true
StringUtils.equalsIgnoreCase(null, "abc")  = false
StringUtils.equalsIgnoreCase("abc", null)  = false
StringUtils.equalsIgnoreCase("abc", "abc") = true
StringUtils.equalsIgnoreCase("abc", "ABC") = true
</pre>

@param str1 the first String, may be null
@param str2 the second String, may be null
@return <code>true</code> if the Strings are equal, case insensitive, or
both <code>null</code>