slf4j-log4j12-1.7.6 and log4j-over-slf4j-1.7.7 both present in classpath generate error "Detected both log4j-over-slf4j.jar AND slf4j-log4j12.jar on the class path, preempting StackOverflowError"

[tfrancart]

This should not happen : http://www.slf4j.org/codes.html
This prevents deployment on Tomcat.

log4j-over-slf4j is coming from spring-boot-starter, this dependency should probably be excluded.

[tfrancart]

Proposed fix in pom.xml, which solves the issue:

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-integration</artifactId>
			<version>1.1.4.RELEASE</version>
			<exclusions>
				<exclusion>
					<groupId>org.slf4j</groupId>
					<artifactId>log4j-over-slf4j</artifactId>
				</exclusion>
			</exclusions>
		</dependency>

Strangely enough, the original problem is not triggered in Tomcat8.5 on Windows, but was triggered on Tomcat8 on Ubuntu

[oddek]

Proposed fix in pom.xml, which solves the issue:

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-integration</artifactId>
			<version>1.1.4.RELEASE</version>
			<exclusions>
				<exclusion>
					<groupId>org.slf4j</groupId>
					<artifactId>log4j-over-slf4j</artifactId>
				</exclusion>
			</exclusions>
		</dependency>

Strangely enough, the original problem is not triggered in Tomcat8.5 on Windows, but was triggered on Tomcat8 on Ubuntu

Thanks a lot. This fixes it for Tomcat 9 on Ubuntu as well