In a new Spring Boot application, when I gradle bootRun, I see this error:
Failed to instantiate [ch.qos.logback.classic.LoggerContext]
Reported exception:
java.lang.AbstractMethodError: ch.qos.logback.classic.pattern.EnsureExceptionHandling.process(Lch/qos/logback/core/Context;Lch/qos/logback/core/pattern/Converter;)V
at ch.qos.logback.core.pattern.PatternLayoutBase.start(PatternLayoutBase.java:86)
at ch.qos.logback.classic.encoder.PatternLayoutEncoder.start(PatternLayoutEncoder.java:28)
at ch.qos.logback.classic.BasicConfigurator.configure(BasicConfigurator.java:50)
at ch.qos.logback.classic.util.ContextInitializer.autoConfig(ContextInitializer.java:164)
at org.slf4j.impl.StaticLoggerBinder.init(StaticLoggerBinder.java:85)
at org.slf4j.impl.StaticLoggerBinder.<clinit>(StaticLoggerBinder.java:55)
at org.slf4j.LoggerFactory.bind(LoggerFactory.java:150)
at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:124)
at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:412)
at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:357)
at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:383)
at com.klarna.risk.decision.application.RiskDecisionApplication.<clinit>(RiskDecisionApplication.java:14)
build.gradle:
buildscript {
repositories {
jcenter()
maven { url 'http://repo.spring.io/release' }
}
dependencies {
classpath 'org.gretty:gretty:+'
}
}
plugins {
id 'org.springframework.boot' version '2.1.9.RELEASE'
id 'io.spring.dependency-management' version '1.0.8.RELEASE'
id 'java'
id 'war'
}
apply plugin: 'org.gretty'
repositories {
jcenter()
maven { url 'http://repo.spring.io/release' }
}
gretty { // for Gradle 4.0+
springBoot = true
springBootVersion = '2.1.9.RELEASE'
httpPort = 8080
contextPath = ''
}
repositories {
mavenCentral()
}
group = 'com.example.newapp'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8
targetCompatibility = 1.8
sourceSets {
test {
java {
srcDirs = ['src/test/java', 'src/api-test/java']
}
}
}
configurations {
compile.exclude module: "spring-boot-starter-tomcat"
}
dependencies {
implementation 'org.springframework.boot:spring-boot-starter'
implementation "org.springframework.boot:spring-boot-starter-jetty"
testImplementation 'org.springframework.boot:spring-boot-starter-test'
}
What is the problem?
When I check with gradle dependencyInsight --dependency logback, I see:
> Task :dependencyInsight
ch.qos.logback:logback-classic:1.1.3 (selected by rule)
variant "compile" [
org.gradle.status = release (not requested)
org.gradle.usage = java-api
org.gradle.libraryelements = jar (compatible with: classes)
org.gradle.category = library (not requested)
Requested attributes not found in the selected variant:
org.gradle.dependency.bundling = external
org.gradle.jvm.version = 8
]
ch.qos.logback:logback-classic:1.1.3
\--- compileClasspath
ch.qos.logback:logback-classic:1.2.3 -> 1.1.3
\--- org.springframework.boot:spring-boot-starter-logging:2.1.9.RELEASE
\--- org.springframework.boot:spring-boot-starter:2.1.9.RELEASE
+--- compileClasspath (requested org.springframework.boot:spring-boot-starter)
+--- org.springframework.boot:spring-boot-starter-web:2.1.9.RELEASE
| +--- compileClasspath (requested org.springframework.boot:spring-boot-starter-web)
| \--- org.springframework.boot:spring-boot-starter-websocket:2.1.9.RELEASE
| \--- compileClasspath
+--- org.springframework.boot:spring-boot-starter-json:2.1.9.RELEASE
| +--- org.springframework.boot:spring-boot-starter-web:2.1.9.RELEASE (*)
| \--- org.springframework.boot:spring-boot-starter-jersey:2.1.9.RELEASE
| \--- compileClasspath (requested org.springframework.boot:spring-boot-starter-jersey)
\--- org.springframework.boot:spring-boot-starter-validation:2.1.9.RELEASE
\--- org.springframework.boot:spring-boot-starter-jersey:2.1.9.RELEASE (*)
ch.qos.logback:logback-core:1.2.3 (selected by rule)
variant "compile" [
org.gradle.status = release (not requested)
org.gradle.usage = java-api
org.gradle.libraryelements = jar (compatible with: classes)
org.gradle.category = library (not requested)
Requested attributes not found in the selected variant:
org.gradle.dependency.bundling = external
org.gradle.jvm.version = 8
]
ch.qos.logback:logback-core:1.1.3 -> 1.2.3
\--- ch.qos.logback:logback-classic:1.1.3
+--- compileClasspath
\--- org.springframework.boot:spring-boot-starter-logging:2.1.9.RELEASE (requested ch.qos.logback:logback-classic:1.2.3)
\--- org.springframework.boot:spring-boot-starter:2.1.9.RELEASE
+--- compileClasspath (requested org.springframework.boot:spring-boot-starter)
+--- org.springframework.boot:spring-boot-starter-web:2.1.9.RELEASE
| +--- compileClasspath (requested org.springframework.boot:spring-boot-starter-web)
| \--- org.springframework.boot:spring-boot-starter-websocket:2.1.9.RELEASE
| \--- compileClasspath
+--- org.springframework.boot:spring-boot-starter-json:2.1.9.RELEASE
| +--- org.springframework.boot:spring-boot-starter-web:2.1.9.RELEASE (*)
| \--- org.springframework.boot:spring-boot-starter-jersey:2.1.9.RELEASE
| \--- compileClasspath (requested org.springframework.boot:spring-boot-starter-jersey)
\--- org.springframework.boot:spring-boot-starter-validation:2.1.9.RELEASE
\--- org.springframework.boot:spring-boot-starter-jersey:2.1.9.RELEASE (*)
(*) - dependencies omitted (listed previously)
A web-based, searchable dependency report is available by adding the --scan option.
Seems that Spring Boot 2.1.9 is using org.springframework.boot:spring-boot-starter-logging:2.1.9.RELEASE, which uses logback-classic:1.1.3. Somewhere in the Google tells me that Spring Boot dependency management has a bug which permits distinct versions of logback-core and logback-classic here and causes conflicts.
I added the dependency of logback-core:1.1.3 and the problem is gone.
compile group: 'ch.qos.logback', name: 'logback-core', version: '1.1.3'
If you face the same problem, be sure to check the version of logback used in Spring Boot.