CODEWITHSUNDEEP
javaspringmavendependenciespackage
Donald Wu
Donald Wu

Reputation: 127

how to resolve packages conflicts on varieties of log4j?

I wrote this pom.xml based on an spring boot sample.

And when I started my app, I got this error:

SLF4J: Detected both log4j-over-slf4j.jar AND bound slf4j-log4j12.jar on the class path, preempting StackOverflowError.

I'm totally new to Java and Maven, and stuck here for quite a while.

I tried to wrote some exclusions in dependency. But it didn't work out. I have no idea which package should be excluded from which. If so, how can the package which is depended on, work normally?

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <!-- Your own application should inherit from spring-boot-starter-parent -->
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-samples</artifactId>
        <version>2.0.0.BUILD-SNAPSHOT</version>
    </parent>
    <artifactId>spring-boot-sample-web-secure-jdbc</artifactId>
    <name>Spring Boot Web Secure JDBC Sample</name>
    <description>Spring Boot Web Secure JDBC Sample</description>
    <url>http://projects.spring.io/spring-boot/</url>
    <organization>
        <name>Pivotal Software, Inc.</name>
        <url>http://www.spring.io</url>
    </organization>
    <properties>
        <main.basedir>${basedir}/../..</main.basedir>
    </properties>
    <dependencies>
        <!-- Compile -->
        <dependency>
            <groupId>org.apache.hadoop</groupId>
            <artifactId>hadoop-common</artifactId>
            <version>3.0.0-alpha2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
        </dependency>
        <!-- Test -->
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

Upvotes: 1

Views: 2577

Answers (3)

Donald Wu
Donald Wu

Reputation: 127

This problem is due to the endless loop between logging facade and logging framework call.

https://www.slf4j.org/codes.html#log4jDelegationLoop

My scenario is slightly more complicate. Besides this loop problem. I have two logging framework.

I end up excluding log4j-over-slf4j and logback-classic.

Upvotes: 0

Markoorn
Markoorn

Reputation: 2565

This happens because spring-boot-starter is pulling in the log4j-over-slf4j dependency, and one of your other dependencies is pulling in log4j.

run mvn dependency:tree and you should be able to find which dependency is pulling in the unwanted log4j and exclude it with

<exclusions>
  <exclusion> 
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
  </exclusion>
  <exclusion> 
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
  </exclusion>
</exclusions>

It may only be one of those depending on what you see on thee mvn dependency:tree

If you would rather use log4j then obviously just exclude log4j-over-slf4j from spring-boot-starter instead.

Upvotes: 5

TuyenNTA
TuyenNTA

Reputation: 1204

I saw on your pom.xml there's no dependency for log4j. You should put this to your pom.xml:

<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.17</version>
</dependency>

Upvotes: -2

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