Selon Christian Stein <[EMAIL PROTECTED]>:
> > - Format methods taking 1 or 2 arguments now delegate to the format method
> > that takes in an array argument. This results in smaller code.
>
> ...but in creation of an Object[], if you only need the 1 or 2 arg variant
> and therefore in slight speed decrease - hey, that's fine with me!
True, but that shouldn't be a problem with modern VMs (it is a short-lived
object).
There are a couple of annoying glitches with said code though:
1. unless I am abused, parsing stops at the first 'invalid
DELIM_START/DELIM_STOP pair', i.e. "{blah} {}" or "{\\}". Shouldn't we continue
parsing in search of a good delimiter pair?
2. what if I want to pass in an Object[] as an argument to the log message? For
example:
Object[] myArray = new Integer[] {new Integer(1)};
log.debug("Array is: {}", myArray);
In this case, I am afraid formatted string will be "Array is: 1" instead of
"Array is: [[java.lang.Integer(1)".
3. you still need to modify all Logger classes for this code to be effective!
FYI, I came up with following code yesterday (didn't post it as I didn't have a
chance to thoroughly test it): it iterates over the messagePattern delimiter
pairs instead of the arguments array.
Note that I still have to handle the case "one {} and an Object[] arg" (previous
case 2).
Cédrik
public static String format(String messagePattern, Object[] arguments) {
int nUsedArgs = 0;
int last = 0;
final int len = messagePattern.length();
int start = messagePattern.indexOf(DELIM_START);
StringBuffer sbuf = null;// optimisation: will be created only if
necessary
while (start != -1 && (start + 1 != len)) {
char delimStop = messagePattern.charAt(start + 1);
char escape = messagePattern.charAt(start - 1);
if ((delimStop != DELIM_STOP) || (escape == '\\')) {
// invalid DELIM_START/DELIM_STOP pair: find next one
last = start + 2;
start = messagePattern.indexOf(DELIM_START, last);
continue;
}
if (null == sbuf) {
sbuf = new StringBuffer(len + 24 * arguments.length);
}
sbuf.append(messagePattern.substring(last, start));
sbuf.append((nUsedArgs < arguments.length) ?
arguments[nUsedArgs] : null);
++nUsedArgs;
last = start + 2;
start = messagePattern.indexOf(DELIM_START, last);
}
if (null != sbuf) {
if (last <= len) {
// append the characters following the last
DELIM_START/DELIM_STOP pair.
sbuf.append(messagePattern.substring(last, len));
}
return sbuf.toString();
} else {
// there was no argument in messagePattern
return messagePattern;
}
}
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