春季启动日志记录。 发现多个 slf4j 实现（logback 和 gradle）

Question

我正在使用 gradle+kotlin 来构建我的 Spring Boot 应用程序。 在应用程序开始时，我收到以下错误。 我明白为什么会出现这个错误，因为我有 2 个不同的 slf4j 实现：logback 和 org.slf4j.impl(inside gradle-api.6.9.1.jar )。 我的 build.gradle 文件中没有包含 gradleApi() 依赖项。 它自己出现。

SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/C:/Users/user/.gradle/caches/6.9.1/generated-gradle-jars/gradle-api-6.9.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/C:/Users/user.gradle/caches/modules-2/files-2.1/ch.qos.logback/logback-classic/1.2.6/b09efa852337fa0dd9859614389eec58dc287116/logback-classic-1.2.6.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.gradle.internal.logging.slf4j.OutputEventListenerBackedLoggerContext]
Exception in thread "main" java.lang.IllegalArgumentException: LoggerFactory is not a Logback LoggerContext but Logback is on the classpath. Either remove Logback or the competing implementation (class org.gradle.internal.logging.slf4j.OutputEventListenerBackedLoggerContext loaded from file:/C:/Users/user/.gradle/caches/6.9.1/generated-gradle-jars/gradle-api-6.9.1.jar). If you are using WebLogic you will need to add 'org.slf4j' to prefer-application-packages in WEB-INF/weblogic.xml: org.gradle.internal.logging.slf4j.OutputEventListenerBackedLoggerContext
  at org.springframework.util.Assert.instanceCheckFailed(Assert.java:702)
  at org.springframework.util.Assert.isInstanceOf(Assert.java:621)
  at org.springframework.boot.logging.logback.LogbackLoggingSystem.getLoggerContext(LogbackLoggingSystem.java:294)
  at org.springframework.boot.logging.logback.LogbackLoggingSystem.beforeInitialize(LogbackLoggingSystem.java:118)
  at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationStartingEvent(LoggingApplicationListener.java:232)
  at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:213)
  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:76)
  at org.springframework.boot.SpringApplicationRunListeners.lambda$starting$0(SpringApplicationRunListeners.java:53)
  at java.base/java.util.ArrayList.forEach(ArrayList.java:1541)
  at org.springframework.boot.SpringApplicationRunListeners.doWithListeners(SpringApplicationRunListeners.java:117)
  at org.springframework.boot.SpringApplicationRunListeners.starting(SpringApplicationRunListeners.java:53)
  at org.springframework.boot.SpringApplication.run(SpringApplication.java:329)
  at org.springframework.boot.SpringApplication.run(SpringApplication.java:1343)
  at org.springframework.boot.SpringApplication.run(SpringApplication.java:1332)
  at com.altruist.accounts.Application.main(Application.java:12)

你有什么想法为什么这个gradle-api.6.9.1.jar出现在类路径中，以及如何从类路径（ gradle-api.6.9.1.jar ）中删除这个 jar ？ 有没有办法手动配置 slf4j 实现的选择？

build.gradle.kts

val lombokVersion: String by project
val mapstructVersion: String by project

plugins {
    id("org.springframework.boot")
}

tasks {
    bootJar {
        archiveFileName.set(project.name + ".jar")
        mainClass.set("com.package.Application")
    }
}

publishing {
    publications {
        create<MavenPublication>("bootJava") {
            artifact(tasks.getByName("bootJar"))
        }
    }
}

springBoot  {
    buildInfo()
}


dependencies {
    implementation(project(":api-layer"))
    implementation("com.package:integration-app-api:1.0.0-SNAPSHOT")
    implementation("org.springframework.boot:spring-boot-starter-data-jpa:2.5.5")
    implementation("org.mapstruct:mapstruct:1.4.2.Final")
    implementation("com.h2database:h2:1.4.200")
    implementation("ch.qos.logback:logback-classic:1.2.6")
    implementation("org.springframework.boot:spring-boot-starter-actuator:2.5.5")
    implementation("org.springframework.cloud:spring-cloud-starter-openfeign:3.0.5")

    compileOnly("org.mapstruct:mapstruct-processor:$mapstructVersion")
    annotationProcessor("org.mapstruct:mapstruct-processor:$mapstructVersion")
    testImplementation("org.springframework.boot:spring-boot-starter-test:2.5.5")
}

description = "api-layer-service"

请分享您的任何想法。

Answer 1

你可以做gradle dependencies

并检查哪个依赖项正在使用 slf4j 并使用排除一个

像这样的 exclude 命令exclude(group="org.slf4j", module="slf4j-log4j12"

我不太确定这个简单的修复，但你可以先尝试将它添加到你的 build.gradle

configurations.all {
   exclude(group="org.slf4j", module="slf4j-log4j12"
}

Answer 2

问题出在 gradle 的 kotlin-dsl 插件中。 它有自己的 slf4j 实现并将其包含在最终版本中。 据我了解，这个记录器实现用于自定义插件和任务。 解决方案：我刚刚将 kotlin-dsl 插件更改为 groovy。

改动前：

plugins {
  `kotlin-dsl`
}

更改后：

plugins {
  groovy
}

我希望这对你和我都有帮助。