将BIT DATA转换为String Java

Question

I have a variable OBJECT_ID stored in DB2 as OBJECT_ID VARCHAR() FOR BIT DATA NOT NULL .

How can I retrieve the String value stored in it?

I have tried following code to convert Binary to String in Java as:

String str = resultset.getObject("OBJECT_ID").toString();
int charCode = Integer.parseInt(str,2);
String str1 = new Character((char)charCode).toString();

But it throws following: NumberFormatException: For input string : "[B@475e586c"

Sure the String is not an Integer but how can I retrieve the String value of a VARCHAR() FOR BIT DATA from DB2 in my java program?

Answer 1

As "[B" of toString indicates the type byte[] , the following should be possible:

byte[] b = (byte[]) resultset.getObject("OBJECT_ID");

Then there is the problem that String is for (Unicode) text, not binary data. A char is two bytes encoded in UTF-16.

You could try to abuse String as:

String s = new String(b, StandardCharsets.ISO_8859_1); // Bad idea.

This depends on OBJECT_ID.

Normally binary data could be encoded as text as Base64, using 64 ASCII chars as "digits."

String s = Base64.getEncoder().encodeToString(b);