Spring Boot ignoring logback-spring.xml

Question

I have 2 Spring Boot (1.4.1-RELEASE) console applications using Logback. Both configuration files are more or less identical, are located in my /src/main/resources

Answer 1

Ok.

I know this is a maven question. But you can 'translate' gradle talk into maven.

The gist of the idea is:

In my root build.gradle file.

I had to exclude these items. The way gradle does it, is this is a "global to this project" type of exclude, so it gets them ALL in one place. But you can do the same "excluding"/scrubbing in maven, it will just look different. The groupid/artifactid's are what is important.

allprojects {


    configurations {
     
        all {
            exclude group: 'org.springframework.boot', module: 'spring-boot-starter-logging'
            exclude group: 'org.springframework.boot', module: 'spring-boot-starter-log4j2'
        }
    }


}

Then in my (top layer) build.gradle (I don't have a monolith, I have a project with multiple modules). I added these dependencies:

implementation group: 'ch.qos.logback', name: 'logback-classic', version: logbackClassicVersion
    
implementation group: 'org.slf4j', name: 'slf4j-api', version: slf4jVersion

My variable values for the two versions happen to be (at this time of writing this post)

    slf4jVersion = "1.7.30"
    logbackClassicVersion = '1.2.3'

How do you find the 2 versions that play nice together?

For example, if you look at:

https://mvnrepository.com/artifact/ch.qos.logback/logback-classic/1.2.3

and find the "compile dependencies", you'll see that

logback-classic/1.2.3

has

org.slf4j » slf4j-api 1.7.25 1.7.30

so somewhere between 1.7.25 and 1.7.30 will play nice with logback-classic/1.2.3

There's probably a better way, but that's how I "get close" at the dependency game.

    slf4jVersion = "1.7.30"
    logbackClassicVersion = '1.2.3'

But you would be better going to maven repostitory or jcenter and finding latest version but also versions that of these 2 things that play nice with each other.

Answer 2

I solved this problem by adding logging.config in application.yml

logging:
  config: classpath:logback-spring.xml

Answer 3

I would specify in application.properties the location of the config file like that.

logging.config=path

Spring might not be looking for this file name. Spring doc

They suggest using this name logback-spring.xml rather than just logback.xml

I would place the configuration in application.properties if possible.

Answer 4

To use Logback, you need to include it and spring-jcl on the classpath. The simplest way to do that is through the starters, which all depend on spring-boot-starter-logging. For a web application, you need only spring-boot-starter-web, since it depends transitively on the logging starter. If you use Maven, the following dependency adds logging for you:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

So remove the logging dependency it is redundant.

Answer 5

I faced the same issue and tried finding if any of logback.xml or logback-grrovy.xml etc. already in claspath, but was not able to find any

Then I tried some changes:

1. Changed name from logback.xml to logback-spring.xml

2. Removed following dependency from pom.xml Instead of

       <dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter</artifactId>
           <exclusions>
               <exclusion>
                   <groupId>org.springframework.boot</groupId>
                   <artifactId>spring-boot-starter-logging</artifactId>
               </exclusion>
           </exclusions>
       </dependency>
       <dependency>
           <groupId>org.slf4j</groupId>
           <artifactId>slf4j-api</artifactId>
           <version>1.7.13</version>
       </dependency>
   

I tried this

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>jcl-over-slf4j</artifactId>
        </dependency>

Answer 6

I know it is somewhat old, but i had the same issue and figured it out... so the reason is simply that you have a logback.xml on your classpath (somewhere, not necessarily in your project which you start, in my case it was a dependency).

Take a look here: org.springframework.boot.logging.AbstractLoggingSystem.initializeWithConventions(LoggingInitializationContext, LogFile)

set a breakpoint, then you will see.

If spring boot doesn't find any logback configurations ("logback-test.groovy", "logback-test.xml", "logback.groovy", "logback.xml") on the classpath, logback-spring.xml will be picked up.