Change Spring framework log level in simple example project?
java, logging, spring, spring-boot, spring-jdbc
Solution
This is the works of `Spring Boot` that is dealing underneath with logging routing `jul`, `jcl` and `log4j` over `slf4j` and employing `Logback` via `slf4j` as you can tell by the distinguishable shortened namespace class names.
All this is nicely visible via the IntelliJ diagram tool directly on the pom file:
This setup is following the best practise as described/depicted in the SLF4J site:
The log is chatty because of the Spring `DEBUG` level. To alter that:
1) Create a `resources` directory under `<projectDir>/src/main` as you would have in a Maven project. 2) Create a `logback.xml` file in it containing:
<configuration>
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>web - %date [%thread] %-5level %logger{36} - %message%n
</pattern>
</encoder>
</appender>
<logger name="org.springframework" level="WARN" />
<root level="INFO">
<appender-ref ref="STDOUT" />
</root>
</configuration>
and voila!
Creating tables
Inserting customer record for John Woo
Inserting customer record for Jeff Dean
Inserting customer record for Josh Bloch
Inserting customer record for Josh Long
Querying for customer records where first_name = 'Josh':
Customer[id=3, firstName='Josh', lastName='Bloch']
Customer[id=4, firstName='Josh', lastName='Long']
Problem
When following this Spring example I was expecting to see output like this: ``` Creating tables Inserting customer record for John Woo Inserting customer record for Jeff Dean ... ``` Instead, I got some `DEBUG` log messages interspersed between every line: ``` Creating tables 12:31:16.474 [main] DEBUG o.s.jdbc.core.JdbcTemplate - Executing SQL statement [drop table customers if exists] 12:31:16.484 [main] DEBUG o.s.jdbc.datasource.DataSourceUtils - Fetching JDBC Connection from DataSource 12:31:16.484 [main] DEBUG o.s.j.d.SimpleDriverDataSource - Creating new JDBC Driver Connection to [jdbc:h2:mem] ... ``` These various answers seem to indicate that this can be resolved by changing the log level in my `log4j.properties` file. However, in following the Spring example a `log4j.properties` file is never mentioned. Interestingly, Spring does appear to be using `log4j` internally: ``` $ grep -R "log4j" * Binary file build/libs/gs-relational-data-access-0.1.0.jar matches ``` I imagine I could use `log4j` to fix this problem, but the manual doesn't seem to have information on where to put `log4j.properties` or how to integrate it into this project. How do I change the log level to remove those `DEBUG` statements? If I need to use a `log4j.properties` file, where do I place it? Do I need to tie it to my `build.gradle` file, or reference it in my `.java` files somehow?