Log4j.properties in Spring boot - spring-boot

Question

How to load Custom Log4j.properties file in Spring boot
My code in application.properties is here
logging.file=E:/Apps_Tek/apps-webservices-log/apps-webservices.log
logging.level.*=INFO
logging.config=log4j.properties
My code in log4j.properties is here
log4j.rootLogger=INFO,ConsoleAppender,FileAppender
log4j.appender.ConsoleAppender=org.apache.log4j.ConsoleAppender
log4j.appender.ConsoleAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.ConsoleAppender.layout.ConversionPattern=%-7p %d [%t] %c [%X{userName}] [%X{accessToken}] - %m%n
log4j.appender.FileAppender=org.apache.log4j.RollingFileAppender
log4j.appender.FileAppender.File=E:/Apps_Tek/apps-webservices-log/apps-webservices.log
log4j.appender.FileAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.FileAppender.layout.ConversionPattern=%-7p %d [%t] %c [%X{userName}] [%X{accessToken}] - %m%n
But i am not getting any expected output i.e., spring boot is not loading log4j.properties file. Spring boot is having its own default logging.
log4j.properties file is in src/main/resources
My question is how to map log4j.properties file with logging.config property in application.properties if it is in src/main/resources.
Please suggest all the required changes.
Thanks for any help in advance.

Answer 1

If you want spring boot to use log4j instead of its own default logging (logback) then you have to exclude default logging and include the log4j dependency for spring boot in your pom.xml:
<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-log4j</artifactId>
</dependency>
that way is going to look for your log4j.properties file located in src/main/resources.
Also if you wish to use properties defined in you application.properties inside the log4j.properties file
for example, you want to have log.file.path defined in your application.properties and use it on log4j.properties
Then you have to define filtering inside your pom.xml:
<filters>
<filter>src/main/resources/application.properties</filter>
</filters>
<resources>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>log4j.properties</include>
</includes>
<filtering>true</filtering>
</resource>
</resources>
That way you can have:
log4j.appender.file.File=${log.file.path}/${project.artifactId}.log
in your log4j.properties file

Answer 2

To exclude default logging and include the log4j dependency for spring boot in your pom.xml:
<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>
if you wish to use log4j properties defined in you application.properties inside the log4j.properties file need to add below property in application.properties file.
logging.config = src/main/resources/log4j2.properties
Then spring boot will read the properties from log4j2.properties file
In log4j2.properties file add the below properties
name=PropertiesConfig
appenders = console, file
appender.console.type = Console
appender.console.name = ConsoleAppender
appender.console.layout.type = PatternLayout
appender.console.layout.pattern = %d{MM:dd HH:mm:ss.SSS} [%t] [%level] [%logger{36}] - %msg%n
appender.file.type = File
appender.file.name = FileAppender
appender.file.fileName=/home/ubuntu/application.log
appender.file.layout.type=PatternLayout
appender.file.layout.pattern= %d{MM:dd HH:mm:ss.SSS} [%t] [%level] [%logger{36}] - %msg%n
loggers=file
logger.file.name=com.project
logger.file.level = debug
logger.file.appenderRefs = file
logger.file.appenderRef.file.ref = FileAppender
rootLogger.level = debug
rootLogger.appenderRefs = stdout
rootLogger.appenderRef.stdout.ref = ConsoleAppender
Is there any other work around which doesnot require to specify
'logging.config = src/main/resources/log4j2.properties' inside application.properties file..?
Note : Spring boot version i am using is 2.1.3.RELEASE
Reference : https://docs.spring.io/spring-boot/docs/current/reference/html/howto-logging.html

Answer 3

My guess is that your pom.xml file is not set up to include the correct log4j dependency. If you do that it should automatically work. See their example at spring-boot-sample-actuator-log4j. Their project includes the artifact spring-boot-starter-log4j which should then allow your log4j.properties to be picked up from the current src/main/resources location and you should no longer need the logging.* entries in your properties. It may also be possible that you need to exclude their spring-boot-starter-logging as I see they are doing that as well. If this does not seem to resolve it please post your POM file in a location I can see it. Please let me know if this works for you.

Answer 4

In case someone faces the same problem, I did not have the spring-boot-starter dependency so I had to add the to the spring-boot-starter-web dependency, this is how it looked:
<!-- Spring Boot Starter Web -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<exclusions>
<!-- Excluding logback dependencies to use l4j2 -->
<exclusion>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
Then you add the Log4j2 Dependency:
<!-- Add Log4j2 Dependency -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-log4j2</artifactId>
</dependency>
Your log4j2.properties file will be used for logging configurations from now on.