Java intercepts strings (determining Chinese characters)

Copy codeThe Code is as follows:
/**
* The intercepted string len is a byte length.
* @ Param str
* @ Param len
* @ Return
* @ Throws UnsupportedEncodingException
*/
Public static String getLimitLengthString (String str, int len ){
Try {
Int counterOfDoubleByte = 0;
Byte [] B = str. getBytes ("gb2312 ");
If (B. length <= len)
Return str;
For (int I = 0; I <len; I ++ ){
If (B [I] <0)
CounterOfDoubleByte ++;
}
If (counterOfDoubleByte % 2 = 0)
Return new String (B, 0, len, "gb2312 ");
Else
Return new String (B, 0, len-1, "gb2312 ");
} Catch (Exception ex ){
DBTools. error (ex );
Return "";
}
}