Spring Boot - log4j2.properties creating log files

问题:

I have used log4j2.properties file with springboot application. Log file was creating but logs are not written into the file.

Please find the details as below:

log4j2.properties

name=PropertiesConfig
property.filename = C:/Logs
appenders = console, file

appender.console.type = Console
appender.console.name = STDOUT
appender.console.layout.type = PatternLayout
appender.console.layout.pattern = [%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n

appender.file.type = File
appender.file.name = LOGFILE
appender.file.fileName=${filename}/app.log
appender.file.layout.type=PatternLayout
appender.file.layout.pattern=[%-5level] %d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %c{1} - %msg%n

loggers=file
logger.file.name=com.java.app //Parent Package name for the application 
logger.file.level = debug
logger.file.appenderRefs = file
logger.file.appenderRef.file.ref = LOGFILE

rootLogger.level = debug
rootLogger.appenderRefs = stdout
rootLogger.appenderRef.stdout.ref = STDOUT

POM.XML

<!-- Logging -->
        <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>
            </exclusions>
        </dependency>

        <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-log4j2</artifactId>
         </dependency>

         <!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-api -->
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-api</artifactId>
        <version>2.11.1</version>
    </dependency>

        <!-- https://mvnrepository.com/artifact/org.apache.logging.log4j/log4j-core -->
    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-core</artifactId>
        <version>2.11.1</version>
    </dependency>

DemoApplication.java

package com.java.app;

    @SpringBootApplication
    public class DemoApplication extends SpringBootServletInitializer {

      private final static Logger log = LogManager.getLogger(DemoApplication.class);

      @Override
      protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {

        return application.sources(DemoApplication.class);
      }

      public static void main(String[] args) {

        log.info("Logger enabled: Entering main \\n\\n");
        SpringApplication.run(DemoApplication.class, args);
        log.info("**** Demo Application Started *****");

      }

    }

Logs are appearing in the console but not written into file as i am not getting the issue.

It's strange, parent package logger "Logger enabled: Entering main \n\n" is written into the file and the other parent logger "**** Demo Application Started *****" is not written into the file as the code is shown above. and also checked for the sub package i.e com.java.app.endpoint loggers even those also not written into the file.

and also identified that the console log is coming like as

2018-08-03 12:55:18.302 INFO 11440 --- [nio-8088-exec-1] c.j.c.e.Classname : logger message

If c.j.c.e. coming as prefix to the class name in logs those are not written into the file why?

I might be doing something wrong. Can anyone please help on this.

回答1:

I also face with this problem following the tutorial on springframework.guru. After searching on spring boot docs then I config my pom.xml with those dependencies

<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>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-log4j2</artifactId>
    </dependency>

and add logging.config=src/main/resources/log4j2.properties in the application.properties file. After that I can see the log appear on my log file when I run the application.

回答2:

Using Spring Boot you can specify log4j2.properties inside the application.properties

logging.config=src/main/resources/log4j2.properties

回答3:

it also seems to be necessary to set log4j as standard apache logging. In general it uses logback. So I had to add

<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>
  </exclusions> 

to my pom.xml

回答4:

Change the POM.xml file as below and it should be working.

 <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>
            <exclusion>
                <groupId>org.springframework.boot</groupId>
                <artifactId>logback-classic</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-log4j2</artifactId>
</dependency>

<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.springframework.boot</groupId>
            <artifactId>logback-classic</artifactId>
        </exclusion>
    </exclusions>
</dependency>

Please note that, Recommendation is to use log4j2.xml instead of log4j2.properties.

回答5:

Spring Boot supports Log4j 2 for logging configuration, you can get how to configure from Configure Log4j for Logging

First you need to exclude spring boot logging

<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>
    </exclusions>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-log4j2</artifactId>
</dependency>

Then have log4j2.json or log4j2.xml or log4j2.yaml in your src/main/resources