ClassCastException in SpringBoot Logging

Question

I'm getting an issue when my application starts up. The application fails when configuring log levels, on a ClassCastException java.util.HashMap cannot be cast to org.springframework.boot.logging.LogLevel.

I've tried setting logging.level.root=INFO in my application.properties and the same error occurs. Not sure what else to try.

I've just upgraded it to SpringBoot 2.x, specifically using this dependency BOM:

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>${springframework.boot.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

Please find the relevant parts of the dependency tree:

[INFO] +- org.springframework.boot:spring-boot-starter-web:jar:2.2.0.RELEASE:compile
[INFO] |  +- org.springframework.boot:spring-boot-starter:jar:2.2.0.RELEASE:compile
[INFO] |  |  +- org.springframework.boot:spring-boot:jar:2.2.0.RELEASE:compile
[INFO] |  |  +- org.springframework.boot:spring-boot-autoconfigure:jar:2.2.0.RELEASE:compile
[INFO] |  |  +- org.springframework.boot:spring-boot-starter-logging:jar:2.2.0.RELEASE:compile
[INFO] |  |  |  +- ch.qos.logback:logback-classic:jar:1.2.3:compile
[INFO] |  |  |  |  \- ch.qos.logback:logback-core:jar:1.2.3:compile
[INFO] |  |  |  +- org.apache.logging.log4j:log4j-to-slf4j:jar:2.12.1:compile
[INFO] |  |  |  |  \- org.apache.logging.log4j:log4j-api:jar:2.12.1:compile
[INFO] |  |  |  \- org.slf4j:jul-to-slf4j:jar:1.7.28:compile
[INFO] |  |  +- org.springframework:spring-core:jar:5.2.0.RELEASE:compile
[INFO] |  |  |  \- org.springframework:spring-jcl:jar:5.2.0.RELEASE:compile
[INFO] |  |  \- org.yaml:snakeyaml:jar:1.25:runtime
[INFO] |  +- org.springframework.boot:spring-boot-starter-json:jar:2.2.0.RELEASE:compile
[INFO] |  |  +- com.fasterxml.jackson.datatype:jackson-datatype-jdk8:jar:2.10.0:compile
[INFO] |  |  +- com.fasterxml.jackson.datatype:jackson-datatype-jsr310:jar:2.10.0:compile
[INFO] |  |  \- com.fasterxml.jackson.module:jackson-module-parameter-names:jar:2.10.0:compile
[INFO] |  +- org.springframework.boot:spring-boot-starter-validation:jar:2.2.0.RELEASE:compile
[INFO] |  |  +- jakarta.validation:jakarta.validation-api:jar:2.0.1:compile
[INFO] |  |  \- org.hibernate.validator:hibernate-validator:jar:6.0.17.Final:compile
[INFO] |  |     \- org.jboss.logging:jboss-logging:jar:3.4.1.Final:compile
[INFO] |  +- org.springframework:spring-web:jar:5.2.0.RELEASE:compile
[INFO] |  \- org.springframework:spring-webmvc:jar:5.2.0.RELEASE:compile
[INFO] |     +- org.springframework:spring-aop:jar:5.2.0.RELEASE:compile
[INFO] |     +- org.springframework:spring-context:jar:5.2.0.RELEASE:compile
[INFO] |     \- org.springframework:spring-expression:jar:5.2.0.RELEASE:compile
[INFO] +- org.springframework.boot:spring-boot-starter-tomcat:jar:2.2.0.RELEASE:provided
[INFO] |  +- jakarta.annotation:jakarta.annotation-api:jar:1.3.5:compile
[INFO] |  +- org.apache.tomcat.embed:tomcat-embed-core:jar:9.0.27:provided
[INFO] |  +- org.apache.tomcat.embed:tomcat-embed-el:jar:9.0.27:provided
[INFO] |  \- org.apache.tomcat.embed:tomcat-embed-websocket:jar:9.0.27:provided
[INFO] +- org.springframework.boot:spring-boot-starter-actuator:jar:2.2.0.RELEASE:compile
[INFO] |  +- org.springframework.boot:spring-boot-actuator-autoconfigure:jar:2.2.0.RELEASE:compile
[INFO] |  |  \- org.springframework.boot:spring-boot-actuator:jar:2.2.0.RELEASE:compile
[INFO] |  \- io.micrometer:micrometer-core:jar:1.3.0:compile
[INFO] |     +- org.hdrhistogram:HdrHistogram:jar:2.1.11:compile
[INFO] |     \- org.latencyutils:LatencyUtils:jar:2.0.3:compile

[INFO] |  |  +- org.springframework.cloud:spring-cloud-starter-oauth2:jar:2.0.0.RELEASE:compile
[INFO] |  |  |  +- org.springframework.cloud:spring-cloud-starter-security:jar:2.0.0.RELEASE:compile
[INFO] |  |  |  |  +- org.springframework.cloud:spring-cloud-starter:jar:2.0.0.RELEASE:compile
[INFO] |  |  |  |  |  +- org.springframework.cloud:spring-cloud-context:jar:2.0.0.RELEASE:compile
[INFO] |  |  |  |  |  |  \- org.springframework.security:spring-security-crypto:jar:5.2.0.RELEASE:compile
[INFO] |  |  |  |  |  +- org.springframework.cloud:spring-cloud-commons:jar:2.0.0.RELEASE:compile
[INFO] |  |  |  |  |  \- org.springframework.security:spring-security-rsa:jar:1.0.5.RELEASE:compile
[INFO] |  |  |  |  \- org.springframework.cloud:spring-cloud-security:jar:2.0.0.RELEASE:compile
[INFO] |  |  |  |     \- org.springframework.boot:spring-boot-starter-security:jar:2.2.0.RELEASE:compile
[INFO] |  |  |  \- org.springframework.security.oauth.boot:spring-security-oauth2-autoconfigure:jar:2.0.0.RELEASE:compile
[INFO] |  |  |     \- org.springframework.security:spring-security-jwt:jar:1.0.9.RELEASE:compile
[INFO] |  |  |        \- org.bouncycastle:bcpkix-jdk15on:jar:1.56:compile
[INFO] |  |  |           \- org.bouncycastle:bcprov-jdk15on:jar:1.56:compile

Here is the stacktrace:

Caused by: java.lang.ClassCastException: java.util.HashMap cannot be cast to org.springframework.boot.logging.LogLevel
    at java.util.HashMap.forEach(HashMap.java:1289)
    at org.springframework.boot.context.logging.LoggingApplicationListener.setLogLevels(LoggingApplicationListener.java:398)
    at org.springframework.boot.context.logging.LoggingApplicationListener.initializeFinalLoggingLevels(LoggingApplicationListener.java:337)
    at org.springframework.boot.context.logging.LoggingApplicationListener.initialize(LoggingApplicationListener.java:288)
    at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationEnvironmentPreparedEvent(LoggingApplicationListener.java:245)
    at org.springframework.boot.context.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:222)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:172)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:165)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:127)
    at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:76)
    at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:53)
    at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:345)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:308)

application.properties

logging.level.root=warn
logging.level.org.springframework.web=debug
logging.level.org.hibernate=error
logging.level.com.my.package.name=error

Clearly the problem here is the values in this levels map are hashmaps, instead of strings.... Not sure why they are that way though.

Answer 1

try setting the logging value to WARN and debug=true and have a check.

in your properties file set the values like this

logging.level.root=warn
logging.level.org.springframework.web=debug
logging.level.org.hibernate=error

in log4j.xml it will look like this

<root>
        <level value="WARN"/>
        <appender-ref ref="console" />
        <appender-ref ref="file"/>

</root>

for more details about logging in spring boot please read the below link https://howtodoinjava.com/spring-boot2/logging/spring-boot-logging-configurations/