Run maven gwt application in hosted mode - gwt

Question

I have created gwt maven project and I want run it so from command line I am providing:
mvn compile gwt:run -DrunTarget=com.engile.Engile/Engile.html
But In logs it shows:
ava.lang.IncompatibleClassChangeError: Implementing class
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:1847)
at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:890)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1354)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1233)
at com.appops.server.data.hibernate.SessionProvider.createSessionFactory(SessionProvider.java:46)
at com.appops.server.data.hibernate.HibernateDataSourceConnector.init(HibernateDataSourceConnector.java:39)
at com.engile.server.services.ConfigurationServlet.init(ConfigurationServlet.java:45)
at com.google.inject.servlet.ServletDefinition.init(ServletDefinition.java:117)
at com.google.inject.servlet.ManagedServletPipeline.init(ManagedServletPipeline.java:82)
at com.google.inject.servlet.ManagedFilterPipeline.initPipeline(ManagedFilterPipeline.java:102)
at com.google.inject.servlet.GuiceFilter.init(GuiceFilter.java:172)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275)
at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:397)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:108)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3709)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4363)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:525)
and pom.xml includes:
<properties>
<!-- Convenience property to set the GWT version -->
<gwtVersion>2.4.0</gwtVersion>
<!-- GWT needs at least java 1.5 -->
<webappDirectory>${project.build.directory}/${project.build.finalName}</webappDirectory>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.eclipse.m2e</groupId>
<artifactId>lifecycle-mapping</artifactId>
<version>1.0.0</version>
<configuration>
<lifecycleMappingMetadata>
<pluginExecutions>
<pluginExecution>
<pluginExecutionFilter>
<groupId>org.codehaus.mojo</groupId>
<artifactId>gwt-maven-plugin</artifactId>
<!-- <versionRange>[2.5.0,)</versionRange> -->
<version>${gwtVersion}</version>
<goals>
<goal>resources</goal>
<goal>compile</goal>
<goal>i18n</goal>
<goal>generateAsync</goal>
</goals>
<configuration>
<runTarget>Engile.html</runTarget>
<hostedWebapp>${project.build.directory}/${project.build.finalName} </hostedWebapp>
<modules>
<module>com.engile.Engile</module>
</modules>
<!-- <runTarget>com.engile.Engile/Engile.html</runTarget> -->
</configuration>
</pluginExecutionFilter>
<action>
<execute />
</action>
</pluginExecution>
<pluginExecution>
<pluginExecutionFilter>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<versionRange>[2.1.1,)</versionRange>
<goals>
<goal>exploded</goal>
</goals>
</pluginExecutionFilter>
<action>
<execute />
</action>
</pluginExecution>
</pluginExecutions>
</lifecycleMappingMetadata>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.5.1</version>
<configuration>
<webappDirectory>${webappDirectory}</webappDirectory>
</configuration>
</plugin>
</plugins>
</build>
In build path in source section I am providing outputfolder of src/main/java is target/classes and default output folder is:
engilev2_with_mavenold/src/main/webapp/WEB-INF/classes
is anything is wrong, I don't understand the webapp/classes folder and target/classes folder where java classes are compiled to ?

Answer 1

You have not configured gwt-maven-plugin in your build tag. You are only configuring maven-compiler-plugin and lifecycle-mapping plugin. The gwt-maven-plugin under lifecycle-plugin is only to inform eclipse to avoid invoking gwt compilation in refresh cycles,
You have the same issue in the other stackoverflow question too -
The parameters 'runTarget' for goal org.codehaus.mojo:gwt-maven-plugin:2.5.0:run are missing or invalid
Add another plugin tag in your pom.xml under buil tag after maven-compiler-plugin
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>gwt-maven-plugin</artifactId>
<!-- <versionRange>[2.5.0,)</versionRange> -->
<version>${gwtVersion}</version>
<goals>
<goal>resources</goal>
<goal>compile</goal>
<goal>i18n</goal>
<goal>generateAsync</goal>
</goals>
<configuration>
<runTarget>Engile.html</runTarget>
<hostedWebapp>${project.build.directory}/${project.build.finalName} </hostedWebapp>
<modules>
<module>com.engile.Engile</module>
</modules>
<!-- <runTarget>com.engile.Engile/Engile.html</runTarget> -->
</configuration>
</plugin>