Log4j2配置-找不到 log4j2配置文件

最近我决定学习如何使用 log4j2日志记录器。我下载了所需的 jar 文件、创建的库、 xml 配置文件并尝试使用它。不幸的是，我在控制台(Eclipse)中得到了这个语句:

ERROR StatusLogger No log4j2 configuration file found. Using default configuration:       logging only errors to the console.

这是我的测试类代码:

package log4j.test;


import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;


public class Log4jTest
{
static final Logger logger = LogManager.getLogger(Logger.class.getName());


public static void main(String[] args) {
logger.trace("trace");
logger.debug("debug");
logger.info("info");
logger.warn("warn");
logger.error("error");
logger.fatal("fatal");
}
}

以及我的 xml 配置文件:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration package="log4j.test"
status="WARN">
<Appenders>
<Console name="Console" target="SYSTEM_OUT">
<PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
</Console>
</Appenders>
<Loggers>
<Logger name="log4j.test.Log4jTest" level="trace">
<AppenderRef ref="Console"/>
</Logger>
<Root level="trace">
<AppenderRef ref="Console"/>
</Root>
</Loggers>
</Configuration>

我也试过在没有 <Logger>标记的 xml、包规范和各种文件夹/包目录中使用 xml，但没有用。现在，我的 log4j2.xml文件直接位于 Eclipse 中的项目文件夹中。

188596 次浏览
小开

Is this a simple eclipse java project without maven etc? In that case you will need to put the log4j2.xml file under src folder in order to be able to find it on the classpath. If you use maven put it under src/main/resources or src/test/resources

小开

You need to choose one of the following solutions:

  1. Put the log4j2.xml file in resource directory in your project so the log4j will locate files under class path.
  2. Use system property -Dlog4j.configurationFile=file:/path/to/file/log4j2.xml
小开

Eclipse will never see a file until you force a refresh of the IDE. Its a feature! So you can put the file all over the project and Eclipse will ignore it completely and throw these errors. Hit refresh in Eclipse project view and then it works.

小开

Was following the documentations - Apache Log4j2 Configuratoin and Apache Log4j2 Maven in configuring log4j2 with yaml. As per the documentation, the following maven dependencies are required:

  <dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>2.8.1</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.8.1</version>
</dependency>

and

<dependency>
<groupId>com.fasterxml.jackson.dataformat</groupId>
<artifactId>jackson-dataformat-yaml</artifactId>
<version>2.8.6</version>
</dependency>

Just adding these didn't pick the configuration and always gave error. The way of debugging configuration by adding -Dorg.apache.logging.log4j.simplelog.StatusLogger.level=TRACE helped in seeing the logs. Later had to download the source using Maven and debugging helped in understanding the depended classes of log4j2. They are listed in org.apache.logging.log4j.core.config.yaml.YamlConfigurationFactory:

com.fasterxml.jackson.databind.ObjectMapper
com.fasterxml.jackson.databind.JsonNode
com.fasterxml.jackson.core.JsonParser
com.fasterxml.jackson.dataformat.yaml.YAMLFactory

Adding dependency mapping for jackson-dataformat-yaml will not have the first two classes. Hence, add the jackson-databind dependency to get yaml configuration working:

<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.8.6</version>
</dependency>

You may add the version by referring to the Test Dependencies section of log4j-api version item from MVN Repository. E.g. for 2.8.1 version of log4j-api, refer this link and locate the jackson-databind version.

Moreover, you can use the below Java code to check if the classes are available in the classpath:

System.out.println(ClassLoader.getSystemResource("log4j2.yml")); //Check if file is available in CP
ClassLoader cl = Thread.currentThread().getContextClassLoader(); //Code as in log4j2 API. Version: 2.8.1
String [] classes = {"com.fasterxml.jackson.databind.ObjectMapper",
"com.fasterxml.jackson.databind.JsonNode",
"com.fasterxml.jackson.core.JsonParser",
"com.fasterxml.jackson.dataformat.yaml.YAMLFactory"};


for(String className : classes) {
cl.loadClass(className);
}
小开

Additionally to what Tomasz W wrote, by starting your application you could use settings:

-Dorg.apache.logging.log4j.simplelog.StatusLogger.level=TRACE

to get most of configuration problems.

For details see Log4j2 FAQ: How do I debug my configuration?

小开

In my case I had to put it in the bin folder of my project even the fact that my classpath is set to the src folder. I have no idea why, but it's worth a try.

小开

log4j-test.xml => name of the configuration file if placed in /test/resources

     @TestPropertySource(properties = {
"log4j.configurationFile","log4j-test.xml"
})
@CucumberContextConfiguration
@ContextConfiguration(classes = TestConfiguration.class)
public class Steps{
private Logger log = LogManager.getLogger(Steps.class);


//implementation
}

提交答案