java判断字符是否是中文

public class weizhi {public static void main(String[] args) {test("yidong中国");}public static void test(String str){StringBuffer sb=new StringBuffer();StringBuffer sb2=new StringBuffer();System.out.println(str);for(int i=0;i<str.length();i++){//System.out.println(str.substring(i,i+1).matches("[\\u4e00-\\u9fbf]+"));    if(str.substring(i,i+1).matches("[\\u4e00-\\u9fbf]+")){    sb=sb.append(str.charAt(i));        }else{    sb2.append(str.charAt(i));        }     } System.out.println(sb.append(sb2).toString());}}