在配置logback和slf4j时,虽然日志可以正常输出,但上方总有一个报错信息.
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.
maven pom.xml配置
<!-- 依赖软件版本 -->
<properties>
<slf4j.version>1.7.30</slf4j.version>
</properties>
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4j.version}</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-simple-->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>${slf4j.version}</version>
</dependency>
问题分析
org.slf4j.impl.StaticLoggerBinder通常存在于slf4j-nop.jar和slf4j-simple.jar中,虽然项目maven中已引入了simple包,但依然存在报错。说明simple包未真正被加载。
实验多种方式,比如添加slf4j-nop.jar, slf4j-simple.jar, slf4j-log4j12.jar, slf4j-jdk14.jar or logback-classic.jar,发现都么有得到解决。
为了让包更好的加载,在依赖中添加type为jar后,问题得到解决。
解决方式
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4j.version}</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-simple-->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>${slf4j.version}</version>
<!-- 注意,若无type为jar则报错-->
<type>jar</type>
</dependency>
特别注意type标签;