where to put the log4j.properties file in a spring boot application

Question

I have created a log4j.properties file, and I have put it in the resources folder as the application.properties file, in this file I have this line : logging.config=log4j.properties which indicated the name of my log4j properties file, but when I run my application I'm getting this error on my console :

Logging system failed to initialize using configuration from 'log4j.properties'
java.io.FileNotFoundException: C:\Users\***\Desktop\CapRecrute\log4j.properties (The system cannot find the file specified)

so I tried to change the logging.config property to src\\main\\resources\\log4j.properties, and then I got another error :

java.lang.IllegalStateException: Could not initialize Logback logging from src\main\resources\log4j.properties ... Caused by: ch.qos.logback.core.LogbackException: Unexpected filename extension of file [file:/C:/Users/Aimad%20MAJDOU/Desktop/CapRecrute/src/main/resources/log4j.properties]. Should be either .groovy or .xml

in my pom file I have this :

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</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>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

How can I solve this ?

Answer 1

The simplest thing is to use Spring's Logback. You just need to add these 2 lines to application.properties

logging.level.org.springframework.web=DEBUG
logging.level.org.hibernate=ERROR

and make sure there are no other logging related lines.

If you instead want log4j, then configure so in your pom.xml:

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

And then in your paplication.properties:

logging.path=/tmp/logs/
logging.file=/tmp/logs/myapplog.log
logging.config=log4j.properties

Also make sure log4j is in the root of your project (not under resources).

Answer 2

Spring boot is expecting a logback file by default and you have provided log4j configuration. If you add the log4j dependency you should find it works. If you are using maven you can do so like this:

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