Java String with Chinese word only

//package com.demo2s;

public class Main {
    public static void main(String[] argv) throws Exception {
        String str = "\u2323";
        System.out.println(allChinese(str));
    }/*  ww  w. j  a  v  a  2 s. c o m*/

    public static boolean allChinese(String str) {
        if (isNullOrEmpty(str)) {
            return false;
        }
        boolean allChinese = true;
        for (char c : str.toCharArray()) {
            if (!isChinese(c)) {
                allChinese = false;
                break;
            }
        }
        return allChinese;
    }

    public static boolean isNullOrEmpty(String str) {
        return str == null || str.trim().length() == 0;
    }

    public static boolean isChinese(char c) {
        Character.UnicodeBlock ub = Character.UnicodeBlock.of(c);
        return ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS
                || ub == Character.UnicodeBlock.CJK_COMPATIBILITY_IDEOGRAPHS
                || ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A
                || ub == Character.UnicodeBlock.GENERAL_PUNCTUATION
                || ub == Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION
                || ub == Character.UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS;

    }

}