Jonathan Lalou's Blog

Archive for the ‘General’ Category

Depuis quelques jours j’ai quitte Free Mobile. En resume, le reseau n’est toujours pas au niveau, malgre de recentes ameliorations. Le gros point noir reste la data en 3G, ce qui pour moi est le besoin fondamental pour lequel j’investis dans un smartphone et un abonnement telephonique, alors qu’une simple carte prepayee suffirait largement a mes 30 ou 45 minutes de communication telephonique mensuelles.

Je suis donc passe chez Sosh. Premier bilan apres quelques semaines:

• Sosh, ca fonctionne mieux que Free Mobile. Je modere toutefois ce jugement, car si le reseau, les debits et le ping sont sensiblement meilleurs, il n’y a rien de fulgurant. Meme sur le reseau de Orange, il m’arrive souvent de perdre l’UMTS et de retomber en EDGE, voire meme de perdre la connexion data.
• J’ai de nouveau acces Google Maps (et Navigation), ainsi que Google Play, et mes flux RSS sont mis a jour plus regulierement. Ces derniers temps, il me fallait 10 a 15 minutes avant de pouvoir me servir du GPS!
• Je peux lancer un streaming avec une probabilite raisonnable que ca fonctionne
• La batterie de mon Nexus recupere une duree de vie normale ; chez Free, a cause notamment du basculement regulier d’antenne, il m’etait necessaire de charger deux voire trois fois durant la journee!
• Si le reseau fonctionne bien, la logistique n’est par contre pas au point:
• commande passee un jeudi, carte SIM recue le mercredi suivant.
• portage de numero demande pour le samedi d’apres la livraison, mais sera effectue le jeudi d’apres, ie deux semaines apres avoir passe la commande!
• l’interface de gestion de compte utilisateur n’est pas vraiment bien faite (avis personnel).

Bref, meme si ca coute plus cher, au moins ca marche! Je ne suis pas encore alle a New-York ou Mumbai pour verifier le fonctionnement a l’etranger, mais je ne pense pas qu’il y ait de probleme particulier.

Je ne jetterai pas la pierre a Free Mobile ni a Xavier Niel: je leur suis reconnaissant d’avoir fait chuter les prix des abonnements mobiles en quelques mois. Je retournerai peut-etre chez Free dans quelques mois, si leur reseau devient digne de ce nom. Pour le moment, je refuse de payer 15.99€ pour un service qui fonctionne “de temps en temps”… et jamais quand c’est urgent :-@

Case

You have a column of type Date in MySQL. How to get the average value of this series?

(Don’t think to execute select AVG(myColumnDate), it won’t work!)

Fix

Use a query similar to this:

[sql]SELECT FROM_UNIXTIME( ROUND( AVG( UNIX_TIMESTAMP( myDateColumn ) ) ) )

FROM `myTable`

WHERE 1[/sql]

Case

You have a WAR to deploy on Tomcat, let’s say jonathan.war for instance. Usually, the application will be reached through the URL http://machine:port/jonathan.
Let’s say you would like to exclude the WAR name from the address, ie the application to be reached on http://machine:port/. This operation is called “to deploy in root”, since the context will be simple slash: '/'.

Solution

You can implement that with two means:

• rename the war as ROOT.war, then deploy.
• or: edit conf/server.xml, replace [xml]<context>[/xml] with
  [xml]<context path="" docBase="jonathan" debug="0" reloadable="true"> [/xml]

Case

I had the following issue: when I undeployed the WAR from Tomcat using the manager instance, the undeploy failed. As a workaround, I had to restart Tomcat for the undeploy to be taken in account.
This issue occured only in Windows ; when the exact same WAR and the same version of Tomcar on Debian, I was able to deploy and undeploy many times.

Quick Fix

In the %CATALINA_HOME%\conf\context.xml, replace:
[xml]<Context>[/xml]
with:
[xml]<Context antijarlocking="true" antiResourceLocking="true"/>[/xml]

Case

I got the project described in MK Yong’s website. This projects is a sample code of JSF + Spring + Hibernate. The laying DB is a MySQL. For many reasons, I’d rather not to detail, I prefered to a HSQLDB instead of the MySQL.

(Notice: the zip you can download at MK Yong’s website contains many errors, not related to the persistance layer but to JSF itself.)

How to migrate any project from MySQL to HSQLDB?

Solution

You have to follow these steps:

Maven

In the pom.xml, replace:
[xml]<!– MySQL database driver –>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.9</version>
</dependency>
[/xml]
with:
[xml] <!– driver for HSQLdb –>
<dependency>
<groupId>org.hsqldb</groupId>
<artifactId>hsqldb</artifactId>
<version>2.2.8</version>
</dependency>
[/xml]
By the way, you can add Jetty plugin to have shorter development cycles:
[xml] <plugin>
<groupId>org.mortbay.jetty</groupId>
<artifactId>maven-jetty-plugin</artifactId>
<configuration>
<webApp>${basedir}/target/jsf.war</webApp>
<port>8088</port>
</configuration>
</plugin>[/xml]

Persistence

Properties

Replace the content of db.properties file with:[java]jdbc.driverClassName=org.hsqldb.jdbcDriver
jdbc.url=jdbc:hsqldb:hsql://localhost:9001
jdbc.username=sa
jdbc.password=[/java]

Hibernate Mapping

In the *.hbm.xml files:

• in the tag <class>, remove the attribute catalog="..."
• replace the types with fully qualified object types, eg:
  • long with java.lang.Long,
  • string with java.lang.String,
  • timestamp with java.util.Date,
  • etc.

Hibernate Properties

For the property of key hibernate.dialect, replace the value: org.hibernate.dialect.MySQLDialectorg.hibernate.dialect.HSQLDialect with the value: org.hibernate.dialect.HSQLDialect.
To match my needs, I tuned Hibernate properties a bit more, but it may not be needed in all situations:
[xml] <property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.HSQLDialect</prop>
<prop key="hibernate.show_sql">true</prop>
<prop key="hbm2ddl.auto">create-drop</prop>
<prop key="hibernate.hbm2ddl.auto">create-drop</prop>
<prop key="connection.pool_size">1</prop>
<prop key="current_session_context_class">thread</prop>
<prop key="cache.provider_class">org.hibernate.cache.NoCacheProvider</prop>
</props>
</property>
[/xml]

Run

Run the HSQLDB server. IMHO, the quickest is to run the following Maven command:

mvn exec:java -Dexec.mainClass="org.hsqldb.Server"

But you may prefer the old school java -cp hsqldb-XXX.jar org.hsqldb.Server ;-).

Tip! To get a GUI to check the content of the DB instance, you can run:

mvn exec:java -Dexec.mainClass="org.hsqldb.util.DatabaseManager"

Then build and launch Jetty:

mvn clean install jetty:run-exploded

Here you can see the great feature of HSQLDB, that will allow you to create, alter and delete tables on the fly (if hibernate.hbm2ddl.auto is set to create-drop), without any SQL scripts, but only thanks to HBM mapping files.

Case

On running a web application hosted on Jetty, I get the following stracktrace:
[java]Nested in org.springframework.beans.factory.BeanCreationException: Error creating bean with name ‘sessionFactory’ defined in ServletContext resource [/WEB-INF/classes/config/spring/beans/HibernateSessionFactory.xml]: Invocation of init method failed; nested exception is org.hibernate.HibernateException: Unable to instantiate default tuplizer [org.hibernate.tuple.entity.PojoEntityTuplizer]:
java.lang.NoSuchMethodError: org.objectweb.asm.ClassWriter.<init>(I)V[/java]
Unlike what I immediatly thought at first glance, the problem is not induced by the Tuplizer ; the actual error is hidden at the bottom: java.lang.NoSuchMethodError: org.objectweb.asm.ClassWriter.

Here are some of the dependencies:
[java]org.hsqldb:hsqldb:jar:2.2.8:compile
org.springframework:spring:jar:2.5.6:compile
org.hibernate:hibernate:jar:3.2.7.ga:compile
javax.transaction:jta:jar:1.0.1B:compile
| +- asm:asm-attrs:jar:1.5.3:compile
| \- asm:asm:jar:1.5.3:compile[/java]

Fix

Main fix

The case is a classic problem of inherited depencencies. To fix it, you have to excluse ASM 1.5.3, and replace it with more recent version. In the pom.xml, you would then have:
[xml]
<properties>
<spring.version>3.1.0.RELEASE</spring.version>
<hibernate.version>3.2.7.ga</hibernate.version>
<asm.version>3.1</asm.version>
</properties>
…
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate</artifactId>
<version>${hibernate.version}</version>
<exclusions>
<exclusion>
<groupId>asm</groupId>
<artifactId>asm</artifactId>
</exclusion>
<exclusion>
<groupId>asm</groupId>
<artifactId>asm-attrs</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>asm</groupId>
<artifactId>asm</artifactId>
<version>${asm.version}</version>
</dependency>
[/xml]

Other improvements

I took the opportunity to upgrade Spring 2.5 to Spring 3.1 (cf the properties above).
Besides, I modified the *.hbm.xml files to use object types, rather than primary types, eg replacing:
[xml]<id name="jonathanId" type="long">[/xml]
with:
[xml]<id name="jonathanId" type="java.lang.Long">[/xml]

Case

Getting and building a project got on the internet, I got the following stractrace:

[java]
[ERROR] Failed to execute goal on project skillsPoC: Could not resolve dependencies for project lalou.jonathan.poc:skillsPoC:war:1.0-SNAPSHOT: Failure to find javax.transaction:jta:jar:1.0.1B in http://192.168.0.39:8081/nexus/content/repositories/central/ was cached in the local repository, resolution will not be reattempted until the update interval of localRepository has elapsed or updates are
forced -> [Help 1]
[ERROR][/java]

Actually, the needed JAR (javax.transaction:jta:jar:1.0.1B) is depended on by Spring 2.5.

Quick fix

1. Add the following repository in your pom.xml:

   [xml] <repository>
   <id>java.net.m2</id>
   <name>java.net m2 repo</name>
   <url>http://download.java.net/maven/2</url>
   </repository>[/xml]

2. Unlike what I could read on Padova’s JUG blog, you need not get and install manually the jar any longer.
3. Possibly, you may have to disable the block related to the <mirrors> in your settings.xml.

Case

On creating a new JSF 2 page, I get the following warning when the page is displayed:

[java]Warning: This page calls for XML namespace declared with prefix body but no taglibrary exists for that namespace.[/java]

Fix

In the XHTML page, replace the HTML 4 headers:
[xml]<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>…</html>
[/xml]
with XHTML headers:
[xml]<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html">
…</html>
[/xml]

Case

You have a JSF 2 project that you need upgrade with jBoss RichFaces and Ajax4JSF, (I assume the process is similar for other libraries, such as Primefaces, ICEfaces, etc.).

Quick Fix

In XHTML

In XHTML pages, add the namespaces related to Richfaces:[xml] xmlns:a4j="http://richfaces.org/a4j"
xmlns:rich="http://richfaces.org/rich"[/xml]

In Maven

In Maven’s pom.xml, I suggest to add a property, such as:
[xml] <properties>
<richfaces.version>4.1.0.Final</richfaces.version>
</properties>[/xml]

Add the following dependency blocks:
[xml]<dependency>
<groupId>org.richfaces.ui</groupId>
<artifactId>richfaces-components-ui</artifactId>
<version>${richfaces.version}</version>
</dependency>
<dependency>
<groupId>org.richfaces.core</groupId>
<artifactId>richfaces-core-impl</artifactId>
<version>${richfaces.version}</version>
</dependency>[/xml]

Case

While building a JSF 2 project on Maven 3, I got the following error:
LinkageError: loader constraint violation: loader (instance of org/codehaus/plexus/classworlds/realm/ClassRealm) previously initiated loading for a different type with name "javax/el/ExpressionFactory"


Complete Stacktrace:

[java]GRAVE: Critical error during deployment:
java.lang.LinkageError: loader constraint violation: loader (instance of org/codehaus/plexus/classworlds/realm/ClassRealm) previously initiated loading for a different type with name "javax/el/ExpressionFactory"
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 java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf(ClassRealm.java:386)
at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:42)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:244)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:230)
at org.apache.jasper.runtime.JspApplicationContextImpl.getExpressionFactory(JspApplicationContextImpl.java:80)
at com.sun.faces.config.ConfigureListener.registerELResolverAndListenerWithJsp(ConfigureListener.java:693)
at com.sun.faces.config.ConfigureListener.contextInitialized(ConfigureListener.java:243)
at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:540)
at org.mortbay.jetty.servlet.Context.startContext(Context.java:135)
at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1220)
at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:510)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:448)
at org.mortbay.jetty.plugin.Jetty6PluginWebAppContext.doStart(Jetty6PluginWebAppContext.java:110)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)
at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:156)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.jetty.Server.doStart(Server.java:222)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.plugin.Jetty6PluginServer.start(Jetty6PluginServer.java:132)
at org.mortbay.jetty.plugin.AbstractJettyMojo.startJetty(AbstractJettyMojo.java:371)
at org.mortbay.jetty.plugin.AbstractJettyMojo.execute(AbstractJettyMojo.java:307)
at org.mortbay.jetty.plugin.AbstractJettyRunMojo.execute(AbstractJettyRunMojo.java:203)
at org.mortbay.jetty.plugin.Jetty6RunMojo.execute(Jetty6RunMojo.java:184)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
2012-09-19 10:26:37.178::WARN: Failed startup of context org.mortbay.jetty.plugin.Jetty6PluginWebAppContext@f8ff42{/JavaServerFaces,C:\workarea\developme
nt\JavaServerFaces\src\main\webapp}
java.lang.RuntimeException: java.lang.LinkageError: loader constraint violation: loader (instance of org/codehaus/plexus/classworlds/realm/ClassRealm) pre
viously initiated loading for a different type with name "javax/el/ExpressionFactory"
at com.sun.faces.config.ConfigureListener.contextInitialized(ConfigureListener.java:292)
at org.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:540)
at org.mortbay.jetty.servlet.Context.startContext(Context.java:135)
at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1220)
at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:510)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:448)
at org.mortbay.jetty.plugin.Jetty6PluginWebAppContext.doStart(Jetty6PluginWebAppContext.java:110)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)
at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:156)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:152)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.jetty.Server.doStart(Server.java:222)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.plugin.Jetty6PluginServer.start(Jetty6PluginServer.java:132)
at org.mortbay.jetty.plugin.AbstractJettyMojo.startJetty(AbstractJettyMojo.java:371)
at org.mortbay.jetty.plugin.AbstractJettyMojo.execute(AbstractJettyMojo.java:307)
at org.mortbay.jetty.plugin.AbstractJettyRunMojo.execute(AbstractJettyRunMojo.java:203)
at org.mortbay.jetty.plugin.Jetty6RunMojo.execute(Jetty6RunMojo.java:184)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320)
at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
Caused by: java.lang.LinkageError: loader constraint violation: loader (instance of org/codehaus/plexus/classworlds/realm/ClassRealm) previously initiated
loading for a different type with name "javax/el/ExpressionFactory"
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 java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClassFromSelf(ClassRealm.java:386)
at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:42)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:244)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:230)
at org.apache.jasper.runtime.JspApplicationContextImpl.getExpressionFactory(JspApplicationContextImpl.java:80)
at com.sun.faces.config.ConfigureListener.registerELResolverAndListenerWithJsp(ConfigureListener.java:693)
at com.sun.faces.config.ConfigureListener.contextInitialized(ConfigureListener.java:243)
… 41 more
2012-09-19 10:26:37.194::INFO: Started SelectChannelConnector@0.0.0.0:8080[/java]

Quick Fix

In the pom.xml, add the following block of dependency:
[xml] <dependency>
<groupId>javax</groupId>
<artifactId>javaee-web-api</artifactId>
<version>6.0</version>
<scope>provided</scope>
</dependency>[/xml]