Java实现按字节长度截取字符串精简版

看了http://xifeng91.iteye.com/blog/268589的代码，觉的可以让代码更精简些，如下：

public static String bSubstring(String s, int length) throws Exception   { 
    byte[] bytes = s.getBytes("Unicode");   
    int i=0,n=0;
    while(n<length&&i<bytes.length){
       i+=2;
       //判断是否为双字节字符
     if(bytes[i]==0){
          n+=1;
       }else{
          n+=2;
       }
    }
    return new String(bytes,0,i,"Unicode");
}