springboot2.7.5 start error Caused by: java.lang.NoClassDefFoundError: org/slf4j/impl/StaticLoggerBinder

Question

I introduced the spring-boot-starter-web, used its own spring-boot-starter-logging framework, specified the configuration file in yaml, and reported startup errors yaml:

logging:
  level:
    root: info
    com.felix.flink.tutorial.api: debug
  config: classpath:logback-spring.xml

maven:

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>com.felix</groupId>
        <artifactId>flink-tutorial-component</artifactId>
        <version>${revision}</version>
    </dependency>
</dependencies>

exception:

23:45:33.009 [Thread-0] DEBUG org.springframework.boot.devtools.restart.classloader.RestartClassLoader - Created RestartClassLoader org.springframework.boot.devtools.restart.classloader.RestartClassLoader@7abaedae
Exception in thread "restartedMain" java.lang.reflect.InvocationTargetException
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)
Caused by: java.lang.NoClassDefFoundError: org/slf4j/impl/StaticLoggerBinder
    at org.springframework.boot.logging.logback.LogbackLoggingSystem.getLoggerContext(LogbackLoggingSystem.java:293)
    at org.springframework.boot.logging.logback.LogbackLoggingSystem.beforeInitialize(LogbackLoggingSystem.java:118)
    at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationStartingEvent(LoggingApplicationListener.java:238)
    at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:220)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:176)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:169)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:143)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:131)
    at org.springframework.boot.context.event.EventPublishingRunListener.starting(EventPublishingRunListener.java:79)
    at org.springframework.boot.SpringApplicationRunListeners.lambda$starting$0(SpringApplicationRunListeners.java:56)
    at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
    at org.springframework.boot.SpringApplicationRunListeners.doWithListeners(SpringApplicationRunListeners.java:120)
    at org.springframework.boot.SpringApplicationRunListeners.starting(SpringApplicationRunListeners.java:56)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:299)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295)
    at com.felix.flink.tutorial.api.FlinkTutorialApiApplication.main(FlinkTutorialApiApplication.java:15)
    ... 5 more
Caused by: java.lang.ClassNotFoundException: org.slf4j.impl.StaticLoggerBinder
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
    ... 22 more

Process finished with exit code 0

i have import slf4j 2.0.3 derect in the pom,but it doesn't work

Answer 1

SLF4J drastically changed the way its implementations are found between versions 1.x and 2.x. In 1.x, the binding class needed to provide a class named org.slf4j.impl.StaticLoggerBinder - the class that's missing. In 2.x it uses the ServiceLoader mechanism.

Spring Boot currently still uses SLF4J 1.7.36, through spring-boot-starter-web -> spring-boot-starter -> spring-boot-starter-logging. The latter depends on some SLF4J bridges, as well as logback-classic which in turn depends on SLF4J 1.7.32. I think that the 1.7.36 "wins" over the 1.7.32.

Unless one of your other dependencies has a transitive dependency on SLF4J 2.x, everything should work just fine. If you do, then you have a mix of SLF4J 1.x and 2.x, and that's simply not going to work. Replace the 2.x dependency with a 1.x dependency and you should be fine (unless you use the fluent API that was added in 2.x).