Log4j2在spring boot中配置问题

Question

我有多模块spring boot项目，我已经添加了log4j2作为日志记录机制，它在启动服务器时抛出异常。

Exception in thread "pool-1-thread-1" java.lang.NoClassDefFoundError: org/apache/logging/log4j/message/ParameterizedMessage
at org.apache.logging.log4j.message.ParameterizedNoReferenceMessageFactory.newMessage(ParameterizedNoReferenceMessageFactory.java:104)
at org.apache.logging.log4j.message.AbstractMessageFactory.newMessage(AbstractMessageFactory.java:75)
at org.apache.logging.log4j.spi.AbstractLogger.logMessage(AbstractLogger.java:2010)
at org.apache.logging.log4j.spi.AbstractLogger.logIfEnabled(AbstractLogger.java:1884)
at org.apache.logging.log4j.spi.AbstractLogger.error(AbstractLogger.java:793)
at org.apache.logging.log4j.core.util.DefaultShutdownCallbackRegistry.run(DefaultShutdownCallbackRegistry.java:76)
at java.lang.Thread.run(Thread.java:745)

引起：java.lang.ClassNotFoundException：非法访问：此Web应用程序实例已经停止。无法加载[org.apache.logging.log4j.message.ParameterizedMessage]。抛出以下堆栈跟踪以进行调试以及尝试终止导致非法访问的线程。 org.apache.catalina.loader.WebappClassLoaderBase.checkStateForClassLoading（WebappClassLoaderBase.java:1295）org.apache.catalina.loader.WebappClassLoaderBase.loadClass（WebappClassLoaderBase.java:1158）org.apache.catalina.loader.WebappClassLoaderBase.loadClass （WebappClassLoaderBase.java:1119）... 7更多引起：java.lang.IllegalStateException：非法访问：此Web应用程序实例已经停止。无法加载[org.apache.logging.log4j.message.ParameterizedMessage]。抛出以下堆栈跟踪以进行调试以及尝试终止导致非法访问的线程。在org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading（WebappClassLoaderBase.java:1305）org.apache.catalina.loader.WebappClassLoaderBase.checkStateForClassLoading（WebappClassLoaderBase.java:1293）... 9更多

父pom.xml设置

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9</version>
        <exclusions>
            <exclusion>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-logging</artifactId>
            </exclusion>
        </exclusions>
        <type>pom</type>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <exclusions>
            <exclusion>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-logging</artifactId>
            </exclusion>
        </exclusions>
        <version>1.5.9</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-tomcat</artifactId>
        <version><version>1.5.9</version></version>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-log4j2</artifactId>
        <version>1.5.9</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
        <exclusions>
            <exclusion>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-logging</artifactId>
            </exclusion>
        </exclusions>
        <version>1.5.9</version>
    </dependency>

Answer 1

您可以将您的POM更新为

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.9.RELEASE</version>
    <relativePath /> <!-- lookup parent from repository -->
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <exclusions>
            <exclusion>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-logging</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-tomcat</artifactId>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-log4j2</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
        <scope>runtime</scope>
    </dependency>
</dependencies>

注意：添加了h2依赖项以确保类路径上有一些JDBC驱动程序，因为你有一个spring-boot-starter-data-jpa。如果您有其他JDBC依赖项，那么您可以省略h2。