Currently the guard logging checks fire for string literal concatenation, but most compilers these days are smart enough to pre concatenate those ahead of time:
i.e.
"log this" + " and " + "this" will compile to "log this and this" and will not trigger a runtime hit on string concatenation.
Many compilers will even pre-optimize something like this:
public class StringCatConstant {
private static final String MY_CONST = "My String Constant";
public void main(String ...args) {
log.debug("My String Literal concatenated with " + MY_CONST);
}
The guard logging should be modified to only flag concatenation with variables.
Here is more info on it if needed: http://stackoverflow.com/questions/28730607/why-doesnt-the-java-compiler-concatenate-string-literals-if-they-appear-after-a
here is another one focused on performance:
http://www.3pillarglobal.com/insights/performance-optimization-string-concatenation