java中怎么判断一个字符是否是中文？【最好有代码，省的在去造车子】

package test;import java.util.Random;public class IsChineseOrEnglish {    //  GENERAL_PUNCTUATION 判断中文的“号    //  CJK_SYMBOLS_AND_PUNCTUATION 判断中文的。号    //  HALFWIDTH_AND_FULLWIDTH_FORMS 判断中文的，号    public static boolean isChinese(char c) {        Character.UnicodeBlock ub = Character.UnicodeBlock.of(c);        if (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) {            return true;        }        return false;    }    public static void isChinese(String strName) {        char[] ch = strName.toCharArray();        for (int i = 0; i < ch.length; i++) {            char c = ch[i];            if (isChinese(c) == true) {                System.out.println(isChinese(c));                return;            } else {                System.out.println(isChinese(c));                return;            }        }    }    public static void main(String[] args) {        Random r = new Random();        for(int i=0;i<20;i++)        System.out.println(r.nextInt(10)+1);        isChinese("き");        isChinese("中国");    }}
------解决方案--------------------------------------------------------
String string = "汉字";
if(string.length() != string.getBytes().length)
  System.out.println("包含汉字");