RFR: JDK-8005263: Logging APIs takes Supplier for message (original) (raw)

Peter Levart peter.levart at gmail.com
Fri Dec 21 09:04:09 UTC 2012

Hi Henry,

Have you considered reversing the positions of Supplier and Throwable arguments in methods that take both? For example instead of:

695 public void logEx(Level level, Supplier msgSupplier, Throwable thrown) {

the following:

695 public void logEx(Level level,Throwable thrown, Supplier msgSupplier) {

If one chooses this form (taking Throwable and Supplier) it might be because there is some code in the lambda expression that is turned into Suppier that spans multiple lines. Better compact multi-line formatting is possible if lambda is last argument:

logger.logEx( Level.WARN, () -> { StringBuilder sb = new StringBuilder(); for (Foo foo : foos) { sb.append(sb.length() == 0 ? "[" : ","); sb.append(foo); } if (sb.length() > 0) sb.append("]"); return sb.toString(); }, exception );

vs.

logger.logEx(Level.WARN, exception, () -> { StringBuilder sb = new StringBuilder(); for (Foo foo : foos) { sb.append(sb.length() == 0 ? "[" : ","); sb.append(foo); } if (sb.length() > 0) sb.append("]"); return sb.toString(); });

It might be (haven't checked) that you don't need another name for a method (logEx) in that case too.

Regards, Peter

On 12/21/2012 07:28 AM, Henry Jen wrote:

Hi,

This patch adds a couple APIs to java.util.logging.Logger so that construction of log messages only occurs when it is actually to be logged by using Supplier instead of String. Since the idea is to avoid unnecessary construction of log messages, thus APIs imply formatting are not provided. Thus all forms of logrb and log with Parameters are not included. log with Throwable are named to be logEx or logpEx to avoid null ambiguous as it seems like it's quite common usage with logger.log(level, null, thrown) Specdiff and webrev can be found at following, http://cr.openjdk.java.net/~henryjen/ccc/8005263.0/specdiff/diff.html http://cr.openjdk.java.net/~henryjen/ccc/8005263.0/webrev/ Cheers, Henry

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