h/t rgoers The FileAppender doesn’t support two dollar signs on the file name as the file is opened when the appender is started. What you are indicating with two dollar signs is that you want – potentially – a different file name for each event. With a single $ (as in ${sys:logFilename}), the system will … Read more
Go ahead: program to the log4j2 API instead of slf4j It’s safe: the Log4j2 API offers the exact same guarantees as slf4j – and more. Now that Log4j2 itself is separated into an API and an implementation module, there is no longer any value in using SLF4J. Yes, it is good engineering practice to keep … Read more
The Easy Way : EDITED according to log4j2 version 2.4 FAQ You can set a logger’s level with the class Configurator from Log4j Core. BUT be aware that the Configurator class is not part of the public API. // org.apache.logging.log4j.core.config.Configurator; Configurator.setLevel(“com.example.Foo”, Level.DEBUG); // You can also set the root logger: Configurator.setRootLevel(Level.DEBUG); Source The Preferable Way … Read more
This works quite differently in log4j2 than in log4j-1.2. In log4j2, you would create a plugin for this. The manual has an explanation with an example for a custom appender here: http://logging.apache.org/log4j/2.x/manual/extending.html#Appenders It may be convenient to extend org.apache.logging.log4j.core.appender.AbstractAppender, but this is not required. When you annotate your custom Appender class with @Plugin(name=”MyCustomAppender”, …., the … Read more
When using JDK 8 and an IDE (or any other code processing tool/framework) with its own compiler, like Eclipse, you have to update the tool to a version with Java 8 support, even if you are not using the newer Java 8 features. The reason is that the compiler must be able to load the newer class files … Read more