I have a Maven GWT project. I included Hibernate and HSQLDB as persistence layer. Running the unit tests is fine, but when it try to run the server component, logging does not work and so I am blind to the errors on the server side. The errors I encouter are:
[ERROR] log4j:ERROR A "org.apache.log4j.RollingFileAppender" object is
not assig nable to a "org.apache.log4j.Appender" variable. [ERROR]
log4j:ERROR The class "org.apache.log4j.Appender" was loaded by
[ERROR] log4j:ERROR [sun.misc.Launcher$AppClassLoader@baf1915] whereas
object of type [ERROR] log4j:ERROR
"org.apache.log4j.RollingFileAppender" was loaded by [WebApp
ClassLoader=1312837549@4e404fad]. [ERROR] log4j:ERROR Could not
instantiate appender named "file". [ERROR] log4j:ERROR A
"org.apache.log4j.ConsoleAppender" object is not assignabl e to a
"org.apache.log4j.Appender" variable. [ERROR] log4j:ERROR The class
"org.apache.log4j.Appender" was loaded by [ERROR] log4j:ERROR
[sun.misc.Launcher$AppClassLoader@baf1915] whereas object of type
[ERROR] log4j:ERROR "org.apache.log4j.ConsoleAppender" was loaded by
[WebAppClas sLoader=1312837549@4e404fad]. [ERROR] log4j:ERROR Could
not instantiate appender named "stdout".
From googling I am pretty sure it is because two instances of the log4j.jar are present.
Is there a good way or best practice way to solve this issue? I run the project in development mode from the console.
My Pom.xml looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>testproject</groupId>
<artifactId>trustme-mdm-gwtp</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<name>GWTP Basic</name>
<description>Basic GWTP application</description>
<properties>
<!-- client -->
<gwt.version>2.6.0</gwt.version>
<gwtp.version>1.2.1</gwtp.version>
<gin.version>2.1.2</gin.version>
<!-- server -->
<guice.version>3.0</guice.version>
<!-- testing -->
<junit.version>4.7</junit.version>
<jukito.version>1.4</jukito.version>
<!-- maven -->
<gwt-maven-plugin.version>2.6.0</gwt-maven-plugin.version>
<maven-surefire-plugin.version>2.6</maven-surefire-plugin.version>
<maven-compiler-plugin.version>2.3.2</maven-compiler-plugin.version>
<maven-resources-plugin.version>2.5</maven-resources-plugin.version>
<maven-processor-plugin.version>2.0.5</maven-processor-plugin.version>
<maven-build-helper-plugin.version>1.7</maven-build-helper-plugin.version>
<target.jdk>1.7</target.jdk>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<webappDirectory>${project.build.directory}/${project.build.finalName}</webappDirectory>
</properties>
<build>
<outputDirectory>${webappDirectory}/WEB-INF/classes</outputDirectory>
<plugins>
<!-- JUnit Testing - skip *.GwtTest cases -->
<!-- 'mvn test' - runs the Jukito tests -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>${maven-surefire-plugin.version}</version>
<configuration>
<includes>
<include>**/*Test.java</include>
</includes>
<excludes>
<exclude>**/*GwtTest.java</exclude>
</excludes>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
<!-- GWT -->
<!-- 'mvn gwt:run' - runs development mode -->
<!-- 'mvn gwt:debug' - runs debug mode -->
<!-- 'mvn gwt:compile' - compiles gwt -->
<!-- 'mvn integration-test' - runs the gwt tests (*GwtTest.java) -->
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>gwt-maven-plugin</artifactId>
<version>${gwt.version}</version>
<configuration>
<!-- With multiple tests use GwtTestSuite.java for speed -->
<includes>**/*GwtTest.java</includes>
<extraJvmArgs>-Xss1024K -Xmx1024M -XX:MaxPermSize=256M</extraJvmArgs>
<copyWebapp>true</copyWebapp>
<hostedWebapp>${webappDirectory}</hostedWebapp>
<runTarget>Project.html</runTarget>
<modules>
<module>testproject.Project</module>
</modules>
</configuration>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>test</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
<dependencies>
<!-- Google Web Toolkit -->
<dependency>
<groupId>com.google.gwt</groupId>
<artifactId>gwt-user</artifactId>
<version>${gwt.version}</version>
</dependency>
<!-- GWT-Platform -->
<dependency>
<groupId>com.gwtplatform</groupId>
<artifactId>gwtp-all</artifactId>
<version>${gwtp.version}</version>
</dependency>
<!-- DI -->
<dependency>
<groupId>com.google.inject</groupId>
<artifactId>guice</artifactId>
<version>${guice.version}</version>
</dependency>
<dependency>
<groupId>com.google.inject.extensions</groupId>
<artifactId>guice-servlet</artifactId>
<version>${guice.version}</version>
</dependency>
<dependency>
<groupId>com.google.inject.extensions</groupId>
<artifactId>guice-assistedinject</artifactId>
<version>${guice.version}</version>
</dependency>
<dependency>
<groupId>com.google.gwt.inject</groupId>
<artifactId>gin</artifactId>
<version>${gin.version}</version>
</dependency>
<!-- Test -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.jukito</groupId>
<artifactId>jukito</artifactId>
<version>${jukito.version}</version>
<scope>test</scope>
</dependency>
<!-- Hibernate -->
<!-- for JPA, use hibernate-entitymanager instead of hibernate-core -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>4.3.5.Final</version>
</dependency>
<!-- hSQLDB -->
<dependency>
<groupId>org.hsqldb</groupId>
<artifactId>hsqldb</artifactId>
<version>2.3.2</version>
</dependency>
<!-- add slf4j interfaces to classpath -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>1.7.7</version>
</dependency>
<!-- GWT-Log -->
<dependency>
<groupId>com.allen-sauer.gwt.log</groupId>
<artifactId>gwt-log</artifactId>
<version>3.3.0</version>
</dependency>
</dependencies>
</project>
When I take a look at the \target…\lib folder, these are the jars that are deployed:
antlr-2.7.7.jar aopalliance-1.0.jar commons-collections-3.2.1.jar
commons-lang-2.4.jar commons-logging-1.1.1.jar dom4j-1.6.1.jar
gin-2.1.2.jar guava-16.0.1.jar guava-gwt-16.0.1.jar guice-3.0.jar
guice-assistedinject-3.0.jar guice-servlet-3.0.jar
gwt-jackson-0.4.0.jar gwt-log-3.3.0.jar gwtp-all-1.2.1.jar
gwtp-clients-common-1.2.1.jar gwtp-crawler-1.2.1.jar
gwtp-dispatch-common-client-1.2.1.jar
gwtp-dispatch-common-shared-1.2.1.jar gwtp-dispatch-rest-1.2.1.jar
gwtp-dispatch-rpc-client-1.2.1.jar gwtp-dispatch-rpc-server-1.2.1.jar
gwtp-dispatch-rpc-server-guice-1.2.1.jar
gwtp-dispatch-rpc-server-spring-1.2.1.jar
gwtp-dispatch-rpc-shared-1.2.1.jar gwtp-mvp-client-1.2.1.jar
gwtp-mvp-shared-1.2.1.jar gwtp-processors-1.2.1.jar
gwtp-tester-1.2.1.jar gwt-user-2.6.1.jar
hibernate-commons-annotations-4.0.4.Final.jar
hibernate-core-4.3.5.Final.jar hibernate-entitymanager-4.3.5.Final.jar
hibernate-jpa-2.1-api-1.0.0.Final.jar hsqldb-2.3.2.jar
jackson-annotations-2.3.0.jar jackson-annotations-2.3.0-sources.jar
jandex-1.1.0.Final.jar javassist-3.18.1-GA.jar javax.inject-1.jar
jboss-logging-3.1.3.GA.jar jboss-logging-annotations-1.2.0.Beta1.jar
jboss-transaction-api_1.2_spec-1.0.0.Final.jar json-20090211.jar
jsr305-1.3.9.jar jsr311-api-1.1.1.jar maven-artifact-3.1.1.jar
plexus-utils-3.0.15.jar servlet-api-2.5.jar
spring-aop-3.2.3.RELEASE.jar spring-beans-3.2.3.RELEASE.jar
spring-context-3.2.3.RELEASE.jar spring-core-3.2.3.RELEASE.jar
spring-expression-3.2.3.RELEASE.jar spring-web-3.2.3.RELEASE.jar
validation-api-1.0.0.GA.jar validation-api-1.0.0.GA-sources.jar
velocity-1.7.jar xml-apis-1.0.b2.jar
I changed the pom.xml to this:
<!-- Google Web Toolkit -->
<dependency>
<groupId>com.google.gwt</groupId>
<artifactId>gwt-servlet</artifactId>
<version>${gwt.version}</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>com.google.gwt</groupId>
<artifactId>gwt-user</artifactId>
<version>${gwt.version}</version>
<scope>provided</scope>
</dependency>
But still no success…
I inserted a screenshot of the dependency tree. My reputation does not allow to paste images. It is stored here:
Best Answer
Thanks for the help (especially Thomas). The guide i used for my project stated log4j and slf4j would be necessary as external references in the pom.xml.
I simply removed it and it is working now. This has taught me however, that it really makes life simpler by not combining server and client dependencies.