I get the following exception when I try to start Tomcat through Eclipse (via right click on Project, Run As -> Run on Server).
SEVERE: Error configuring app
I faced the same problem few days ago with m2eclipse (without WTP integration add on available via m2eclipse-extras) on Eclipse Indigo. I created a Maven Web Module and manually added the Dynamic Web Module facet to it. When I deployed it on Eclipse WST Tomcat Server, it appeared that my Maven dependencies are not getting pushed to the server when the project is published to it.
The solution was simple. Right Click on your web project in Project Explorer -> select 'Properties'. Under project properties, select 'Deployment Assembly'.
The Deployment Assembly property page shows the content that will be published as a assembled artifact by Eclipse to the server. You need to tell Eclipse that you want all your Maven dependencies to be published too.
To do that, click 'Add' button, then select 'Java Build Path Entries'. Click Next and select Maven Dependencies. This will publish the Maven dependency JAR files to the lib folder when Eclipse publishes your project to WST server.
This approach worked for me.
The easiest way to tell what Eclipse will put in your war file for server deployments is to do a right click -> Export -> WAR file. You can then uncompress this and see what's inside.
If you open up ".settings/org.eclipse.wst.common.component" you should see the definition of the web tools webapp, and see something like:
<project-modules id="moduleCoreId" project-version="1.5.0">
<wb-module deploy-name="MyApp">
<wb-resource deploy-path="/" source-path="/src/main/webapp"/>
<wb-resource deploy-path="/WEB-INF/classes" source-path="/src/main/java"/>
<wb-resource deploy-path="/WEB-INF/classes" source-path="/src/main/resources"/>
<property name="java-output-path" value="target/classes"/>
<property name="context-root" value="MyApp"/>
</wb-module>
</project-modules>
On your build path in Eclipse, make sure "Maven Dependencies" appears in Libraries. The last versions of the m2eclipse plugin and WST should automatically pick up the Maven dependencies and drop them in WEB-INF/lib inside your war file.
Last but not least, you may want to consider picking up the latest copy of SpringSource Tool Suite (STS). STS has a number of good features, including bundling the latest m2eclipse and WST. You can still use it with Tomcat (or their version of Tomcat), and it has some archetypes and tutorials in there to get a webapp working quickly.
Enjoy!
Add these files (whichever release you happen to be using) to
apache-tomcat-8.0.35\lib
folder (and restart your server):
spring-aop-4.0.1.RELEASE.jar
spring-beans-4.0.1.RELEASE.jar
spring-context-4.0.1.RELEASE.jar
spring-core-4.0.1.RELEASE.jar
spring-expression-4.0.1.RELEASE.jar
spring-web-4.0.1.RELEASE.jar
spring-webmvc-4.0.1.RELEASE.jar