SLF4J / SLF4J-371 [Resolved] Support the lambda expression in the Logger ==============================
Here's what changed in this issue in the last few minutes. There is 1 comment. View or comment on issue using this link https://jira.qos.ch/browse/SLF4J-371 ============================== 1 comment ------------------------------ Alexander Kiselyov on 26/Dec/21 10:57 PM [~ekolotyluk], I might be missing your point, but I guess any of these 2 samples does what you intended to: {code:java} Supplier<String> task = () -> { System.out.println("task evaluated"); return "called"; }; logger.atDebug().addArgument(task).log("Lazy logging {}");{code} {code:java} logger.atDebug().addArgument(() -> { System.out.println("task evaluated"); return "called"; }).log("Lazy logging {}"); {code} This has an extra call compared to your desired sample (in general N calls will be required, where N is a number of parameters, since there's no varargs version of [addArgument|https://www.slf4j.org/api/org/slf4j/spi/LoggingEventBuilder.html#addArgument(java.util.function.Supplier)] or {{addKeyValue}}, which may actually be useful to have). The version you published ({{log("Lazy logging {}", task.call())}}) simply can't work in any other way: {{task.call()}} is not a [method reference expression|https://docs.oracle.com/javase/specs/jls/se11/html/jls-15.html#jls-15.13] ("refer to the invocation of a method without actually performing the invocation"), but just a regular method invocation, so will obviously be executed by JVM in order to evaluate all the {{log()}} method arguments prior to its actual invocation (again, according to Java Language Specification). ============================== This message was sent by Atlassian Jira (v8.8.0#808000-sha1:e2c7e59) _______________________________________________ slf4j-dev mailing list slf4j-dev@qos.ch http://mailman.qos.ch/mailman/listinfo/slf4j-dev
