How do I configure Spring and SLF4J so that I can get logging?

Solution 1:

In addition to Jatin's answer:

Spring uses Jakarta Commons Logging as a logging API. In order to log to slf4j, you need to make sure commons-logging is not on the classpath. jcl-over-slf4j is a replacement jar for commons-logging.

If you're using maven, you can detect where commons-logging comes from using mvn dependency:tree and exclude it from all dependencies that require it using dependency exclusions. You might need to run mvn dependency:tree several times though, because it only shows the first occurence of a transitive dependency.

<dependency>
  <groupId>org.springframework</groupId>
  <artifactId>spring-context</artifactId>
  <version>${org.springframework.version}</version>
  <exclusions>
    <exclusion>
      <artifactId>commons-logging</artifactId>
      <groupId>commons-logging</groupId>
    </exclusion>
  </exclusions>
</dependency>

Solution 2:

You'll find an example at https://github.com/mbogoevici/spring-samples/tree/master/mvc-basic/trunk. You need to include some dependencies in your POM file to enable logging.

<!-- Logging -->
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>${org.slf4j.version}</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>jcl-over-slf4j</artifactId>
        <version>${org.slf4j.version}</version>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>${org.slf4j.version}</version>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.16</version>
        <scope>runtime</scope>
    </dependency>

Solution 3:

Just for the sake of completeness, a logback-classic variant:

<dependency>
    <groupId>ch.qos.logback</groupId>
    <artifactId>logback-classic</artifactId>
    <version>1.0.0</version>
</dependency>
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>jcl-over-slf4j</artifactId>
    <version>1.6.6</version>
    <scope>runtime</scope>
</dependency>

Do not forget however to disable commons-logging dependency which sprouts from Spring dependency like in the accepted (Stijn's) answer.