将SLF4J与log4j2一起使用时无法实例化SLF4J LoggerFactory

Question

我开始将slf4j与log4j2一起使用，但问题如下。pom文件中我错了什么或缺少什么？

Failed to instantiate SLF4J LoggerFactory

Reported exception:

java.lang.NoClassDefFoundError: org/apache/logging/log4j/spi/AbstractLoggerAdapter

at java.lang.ClassLoader.defineClass1(Native Method)

at java.lang.ClassLoader.defineClass(ClassLoader.java:763)

at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)

at java.net.URLClassLoader.defineClass(URLClassLoader.java:468)

at java.net.URLClassLoader.access$100(URLClassLoader.java:74)

...

我的pom.xml：

<dependencies>
    <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>1.7.30</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-slf4j-impl</artifactId>
        <version>2.12.0</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-api</artifactId>
        <version>2.13.3</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-core</artifactId>
        <version>2.13.3</version>
    </dependency>

</dependencies>

我非常简单的代码：

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class Study {

    static Logger LOGGER = LoggerFactory.getLogger(Study.class);
    public static void main(String... args) {
        LOGGER.info("hello world");
    }
}

Answer 1

我不知道原因是什么，但如果我使用2.11。2、它起作用了

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.7.30</version>
</dependency>
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-slf4j-impl</artifactId>
    <version>2.11.2</version>
</dependency>
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-api</artifactId>
    <version>2.11.2</version>
</dependency>
<dependency>
    <groupId>org.apache.logging.log4j</groupId>
    <artifactId>log4j-core</artifactId>
    <version>2.11.2</version>
</dependency>

Answer 2

尝试对来自一个group pId的所有库使用相同的版本：

...
<dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-slf4j-impl</artifactId>
        <version>2.13.3</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-api</artifactId>
        <version>2.13.3</version>
    </dependency>
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-core</artifactId>
        <version>2.13.3</version>
    </dependency>
...

此外，您还可以尝试在没有org的情况下运行。slf4j依赖项。启动前运行mvn clean install。