java - SpringBoot应用程序中增强Log4J2版本

Question

这个问题已经有答案了:

Interpreting "omitted for conflict" in maven 2 dependency tree (2 个回答)

已关闭 5 年前。

尝试在 Spring Boot APP 中使用最新版本的 Log4J2 版本 2.10。

我们是一个微服务解决方案，因此首先创建一个可重用的模块，其详细信息如下 -

可复用日志组件(POM片段如下)-

    <log4j.version>2.10.0</log4j.version>
    <commons-logging.version>1.2</commons-logging.version>

    <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>
            <exclusion>
                <groupId>org.apache.logging.log4j</groupId>
                <artifactId>log4j-api</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.apache.logging.log4j</groupId>
                <artifactId>log4j-core</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-api</artifactId>
        <version>${log4j.version}</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-core</artifactId>
        <version>${log4j.version}</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-slf4j-impl</artifactId>
        <version>${log4j.version}</version>
    </dependency>
    <dependency>
        <groupId>commons-logging</groupId>
        <artifactId>commons-logging</artifactId>
        <version>${commons-logging.version}</version>
    </dependency>

微服务项目将其称为 -

     <log4j.version>2.10.0</log4j.version>
    <commons-logging.version>1.2</commons-logging.version>
     <dependency>
        <groupId>a.b.c</groupId>
        <artifactId>reusable-logger-starter</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </dependency>

无论将 jar 版本覆盖到 2.10.0，它都会显示 2.7.0 -

问题 1 -> 这正常吗？

我的解决方法是将以下 jar 包含到微服务的 POM 文件中

<dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-api</artifactId>
        <version>${log4j.version}</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-core</artifactId>
        <version>${log4j.version}</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-slf4j-impl</artifactId>
        <version>${log4j.version}</version>
    </dependency>
    <dependency>
        <groupId>a.b.c</groupId>
        <artifactId>reusable-logger-starter</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </dependency>

问题2)有人遇到过类似的问题吗？

Answer 1

解决方案是在微服务的 POM 中包含/覆盖 log4j2 的版本 -

      <properties>
            <log4j2.version>
                   2.10.0
            </log4j2.version>
      </properties>

Dependency mediation - this determines what version of a dependency will be used when multiple versions of an artifact are encountered. Currently, Maven 2.0 only supports using the "nearest definition" which means that it will use the version of the closest dependency to your project in the tree of dependencies. You can always guarantee a version by declaring it explicitly in your project's POM. Note that if two dependency versions are at the same depth in the dependency tree, until Maven 2.0.8 it was not defined which one would win, but since Maven 2.0.9 it's the order in the declaration that counts: the first declaration wins. "nearest definition" means that the version used will be the closest one to your project in the tree of dependencies, eg. if dependencies for A, B, and C are defined as A -> B -> C -> D 2.0 and A -> E -> D 1.0, then D 1.0 will be used when building A because the path from A to D through E is shorter. You could explicitly add a dependency to D 2.0 in A to force the use of D 2.0