Micronaut Logging using Log4j2
In this article, we show how to set up and use Log4j2 for logging in a Micronaut application.
log4j2
Spring Boot Log4j 2 example
In this tutorial, we will show you how to use Apache Log4j 2 in Spring Boot framework. Technologies used : Spring Boot 2.1.2.RELEASE Spring 5.1.4.RELEASE Log4j 2.11.1 Maven 3 Java 8 1. Project Directory 2. Maven The key is exclude the default logback, and include log4j with spring-boot-starter-log4j2 pom.xml <?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" …
log4j2.yml example
A simple log4j2.yml example, just for self-reference P.S Tested with Log4j 2.11.2 1. Jackson for YML Log4j 2 need the following libraries to parse yml file pom.xml <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-api</artifactId> <version>2.11.2</version> </dependency> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-core</artifactId> <version>2.11.2</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.dataformat</groupId> <artifactId>jackson-dataformat-yaml</artifactId> <version>2.9.8</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.9.8</version> </dependency> 2. log4j2.yml src/resources/log4j2.yml Configuration: status: warn appenders: Console: …
log4j2.properties example
A simple log4j2.properties example, just for self-reference P.S Tested with Log4j 2.11.2 src/resources/log4j2.properties status = warn appender.console.type = Console appender.console.name = LogToConsole appender.console.layout.type = PatternLayout appender.console.layout.pattern = [%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} – %msg%n #appender.file.type = File #appender.file.name = LogToFile #appender.file.fileName=logs/app.log #appender.file.layout.type=PatternLayout #appender.file.layout.pattern=[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} – %msg%n # Rotate log file appender.rolling.type = …
log4j2.xml example
Some log4j2.xml examples, just for self-reference P.S Tested with Log4j 2.11.2 1. ConsoleAppender Logs to console. log4j2.xml <?xml version="1.0" encoding="UTF-8"?> <Configuration status="DEBUG"> <Appenders> <Console name="LogToConsole" target="SYSTEM_OUT"> <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} – %msg%n"/> </Console> </Appenders> <Loggers> <!– avoid duplicated logs with additivity=false –> <Logger name="com.mkyong" level="debug" additivity="false"> <AppenderRef ref="LogToConsole"/> </Logger> <Root level="error"> <AppenderRef ref="LogToConsole"/> </Root> …
Log4j 2 – java.lang.NoClassDefFoundError: com/lmax/disruptor/EventTranslatorVararg
Enable the log4j 2 loggers to asynchronous, but hits the following order : $ mvn -Dlog4j2.contextSelector=org.apache.logging.log4j.core.async.AsyncLoggerContextSelector -jar app.jar java.lang.NoClassDefFoundError: com/lmax/disruptor/EventTranslatorVararg at java.lang.ClassLoader.defineClass1 (Native Method) at java.lang.ClassLoader.defineClass (ClassLoader.java:1009) at java.security.SecureClassLoader.defineClass (SecureClassLoader.java:174) at java.net.URLClassLoader.defineClass (URLClassLoader.java:545) at java.net.URLClassLoader.access$100 (URLClassLoader.java:83) at java.net.URLClassLoader$1.run (URLClassLoader.java:453) Solution To fix it, add disruptor pom.xml <dependency> <groupId>com.lmax</groupId> <artifactId>disruptor</artifactId> <version>3.4.2</version> </dependency> Note Read this Making …
Apache Log4j 2 Tutorials
A simple log4j 2 hello world example. Tested with Log4j 2.11.2 Maven 3 Java 8 Note Apache Log4j 2, the fastest Java logging framework, provides significant improvements over its predecessor, Log4j 1.x. 1. Project Directory 2. Maven <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-api</artifactId> <version>2.11.2</version> </dependency> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-core</artifactId> <version>2.11.2</version> </dependency> pom.xml <?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 …
log4j2 – Failed to load class “org.slf4j.impl.StaticLoggerBinder”
The Java project is using log4j2, but look like some components are used SLF4J logging and caused the following error message: SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details. Solution To fix it, we need a SLF4J Bridge. Puts log4j-slf4j-impl in the classpath. pom.xml …