Why are Spring log messages listed as [ERROR] when there seem to be no errors? - spring

Question

I have a GWT/Spring application, building with Maven and the gwt-maven-plugin.
When I run
mvn gwt:run
the gwt-maven-plugin runs the application and everything starts up and runs fine. What's bothering me is that the log messages claim [ERROR] on every line even though there are no apparent errors, and no message ever says what the error might be.
My guess is that [ERROR] on every log line is from the gwt-maven-plugin, since what comes after seems to be Spring's log message like so... [ERROR] INFO:
and when I run the app with mvn jetty:run, I see only the INFO: part of the messages.
Attached is most of the log to standard out. Has anybody seen log output like this, or have any ideas about what could cause a plugin to log info messages as error messages?
[INFO] ------------------------------------------------------------------------
[INFO] Building GWT Maven Archetype 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] >>> gwt-maven-plugin:2.4.0:run (default-cli) # gwt >>>
[INFO]
[INFO] --- maven-resources-plugin:2.4.3:resources (default-resources) # gwt ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 10 resources
[INFO]
[INFO] --- maven-compiler-plugin:2.3.2:compile (default-compile) # gwt ---
[INFO] Nothing to compile - all classes are up to date
[INFO]
[INFO] --- maven-war-plugin:2.1.1:exploded (default) # gwt ---
[INFO] Exploding webapp
[INFO] Assembling webapp [gwt] in [/home/jay/workspace/buildtimer/target/gwt-1.0- SNAPSHOT]
[INFO] Processing war project
[INFO] Copying webapp resources [/home/jay/workspace/buildtimer/src/main/webapp]
[INFO] Webapp assembled in [169 msecs]
[INFO]
[INFO] <<< gwt-maven-plugin:2.4.0:run (default-cli) # gwt <<<
[INFO]
[INFO] --- gwt-maven-plugin:2.4.0:run (default-cli) # gwt ---
[INFO] create exploded Jetty webapp in /home/jay/workspace/buildtimer/target/gwt-1.0- SNAPSHOT
[INFO] auto discovered modules [com.buildtimer.Main]
[ERROR] Nov 14, 2011 7:38:44 PM org.springframework.web.context.ContextLoader initWebApplicationContext
[ERROR] INFO: Root WebApplicationContext: initialization started
[ERROR] Nov 14, 2011 7:38:44 PM org.springframework.context.support.AbstractApplicationContext prepareRefresh
[ERROR] INFO: Refreshing Root WebApplicationContext: startup date [Mon Nov 14 19:38:44 EST 2011]; root of context hierarchy
[ERROR] Nov 14, 2011 7:38:44 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
[ERROR] INFO: Loading XML bean definitions from class path resource [META- INF/applicationContext.xml]
[ERROR] Nov 14, 2011 7:38:44 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
[ERROR] INFO: Loading XML bean definitions from class path resource [META- INF/applicationContext-persistence.xml]
[ERROR] Nov 14, 2011 7:38:44 PM org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
[ERROR] INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory#1e42c6e: defining beans [org.springframework.aop.config.internalAutoProxyCreator,org.springframework.transaction.ann otation.AnnotationTransactionAttributeSource#0,org.springframework.transaction.interceptor.T ransactionInterceptor#0,org.springframework.transaction.config.internalTransactionAdvisor,tr ansactionManager,buildDao,dataSource,sessionFactory]; root of factory hierarchy
[ERROR] Nov 14, 2011 7:38:45 PM org.springframework.jdbc.datasource.DriverManagerDataSource setDriverClassName
[ERROR] INFO: Loaded JDBC driver: com.mysql.jdbc.Driver
[ERROR] SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
[ERROR] SLF4J: Defaulting to no-operation (NOP) logger implementation
[ERROR] SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
[ERROR] Nov 14, 2011 7:38:46 PM org.springframework.orm.hibernate3.LocalSessionFactoryBean buildSessionFactory
[ERROR] INFO: Building new Hibernate SessionFactory
[ERROR] Nov 14, 2011 7:38:48 PM org.springframework.orm.hibernate3.LocalSessionFactoryBean updateDatabaseSchema
[ERROR] INFO: Updating database schema for Hibernate SessionFactory
[ERROR] Nov 14, 2011 7:38:48 PM org.springframework.orm.hibernate3.HibernateTransactionManager afterPropertiesSet
[ERROR] INFO: Using DataSource [org.springframework.jdbc.datasource.DriverManagerDataSource#1b0e438] of Hibernate SessionFactory for HibernateTransactionManager
My web.xml logging configuration is
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>
...
<context-param>
<param-name>log4jConfigLocation</param-name>
<param-value>/WEB-INF/classes/log4j.properties.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
</listener>
...
</web-app>
my log4j.properties.xml file
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
<appender name="rootAppender" class="org.apache.log4j.FileAppender" >
<param name="file" value="app.log"/>
<layout class="org.apache.log4j.PatternLayout">
<param name="ConversionPattern" value="%d %-5p %c - %m%n"/>
</layout>
</appender>
<root>
<priority value ="warn" />
<appender-ref ref="rootAppender" />
</root>
</log4j:configuration>

Answer 1

Not sure how much it is related, but your log indicates that the SLF4J logging framework is not properly initilaized
[ERROR] SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
[ERROR] SLF4J: Defaulting to no-operation (NOP) logger implementation
[ERROR] SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Make sure that you have all three dependencies in your pom (SLF4J, The log4j binding and log4j itself)
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<scope>compile</scope>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<scope>runtime</scope>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<scope>runtime</scope>
<version>1.2.16</version>
</dependency>