Question

We had a a clob column in DB. Now when we extract this clob and try to display it (plain text not html), it prints junk some characters on html screen. The character when directly streamed to a file looks like ” (not the usual double quote on regular keyboard)

One more observation:

System.out.println("”".getBytes()[0]);

prints -108.

Why a character byte should be in negative range ? Is there any way to display it correctly on a html screen ?

Answer 1

Re: your final observation – Java bytes are always signed. To interpret them as unsigned, you can bitwise AND them with an int:

byte[] bytes = "”".getBytes("UTF-8");
for(byte b: bytes)
{
    System.out.println(b & 0xFF);
}

which outputs:

226 
128
157

Note that your string is actually three bytes long in UTF-8.

As pointed out in the comments, it depends on the encoding. For UTF-16 you get:

254
255
32
29

and for US-ASCII or ISO-8859-1 you get

63

which is a question-mark (i.e. “I dunno, some new-fangled character”). Note that:

The behavior of this method [getBytes()] when this string cannot be
encoded in the given charset is unspecified. The CharsetEncoder class
should be used when more control over the encoding process is
required.