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());
	}

}