Am 19.03.2009 20:02, Xueming Shen schrieb:
Ulf Zibis wrote:
Isn't there any way even to avoid instantiating new ..Array-X-coder
for each invocation of StringCoding.x-code(Charset cs, ...)?
Method x-code(byte/char[]) seems to be threadsafe, if replacement
isn't changed, so I suppose, we could cache the ..Array-X-coder.
no. an "external" charset can do whatever it likes, it might be still
the same "object", the de/encoder it "creates" might
be still the same "object' or looks like the same object you might
have cahced, but do total different thing.
At first assumption user could think, that String#getBytes(byte[] buf,
Charset cs) might be faster than String#getBytes(byte[] buf, String
csn), because he assumes, that Charset would be internally created from csn.
As this is only true for the first call, there should be a *note* in
JavaDoc about cost of those methods in comparision. Don't forget (byte[]
...) constructor's JavaDoc too.
Secondly I think, that ASCII and ISO-8859-1 have high percentage here
especially for CORBA applications, so why not have a fast shortcut in
class String without internally using Charset-X-coder like
getASCIIbytes() + getISO_8859_1Bytes(), or more general and sophisticated:
int getBytes(byte[] buf, byte mask) {
int j = 0;
for (int i=0; i<values.length; i++, j++) {
if (values[i] | mask == mask)
buf[j] = (byte)values[i];
continue;
if (isHighSurrogate(values[i])
i++;
buf[j] = '?'; // or default replacement
}
return j;
}
-Ulf
