org.springframework.web.WebAbblicationInitializer.onStartup won't Override interface method - spring

Question

I am attempting a pure java (no web.xml) Spring WebMVC project and I am running into a peculiar issue with the configuration file. I am using exactly the code from this example, where it says "A 100% code-based approach to configuration." However, eclipse says that I must remove the #Override annotation because onStartup does not "implement a superclass method."
This seems like it might be a problem with the versions of Servlet or Spring that I am using, but I don't really know what I might change either of them to which would fix that.
This is a Maven project. I'd like to solve this by adjusting my maven dependencies, rather than using Eclipse configurations.
Here is the configuration file
package com.peak15.jumpgate;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.ContextLoaderListener;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;
public class MyWebAppInitializer implements WebApplicationInitializer {
#Override // TODO figure out why this doesn't override
public void onStartup(ServletContext servletContext) throws ServletException {
WebApplicationContext context = getContext();
servletContext.addListener(new ContextLoaderListener(context));
ServletRegistration.Dynamic dispatcher = servletContext.addServlet("DispatcherServlet", new DispatcherServlet(context));
dispatcher.setLoadOnStartup(1);
dispatcher.addMapping("/*");
}
private AnnotationConfigWebApplicationContext getContext() {
AnnotationConfigWebApplicationContext context
= new AnnotationConfigWebApplicationContext();
context.setConfigLocation("com.peak15.jumpgate");
return context;
}
}
here is pom.xml
<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>jumpgate</groupId>
<artifactId>jumpgate2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<name>JumpGateII</name>
<properties>
<jdk.version>1.8</jdk.version>
<spring.version>3.2.13.RELEASE</spring.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.0.1</version>
</dependency>
</dependencies>
</project>

Answer 1

Check if you have installed jdk 1.8 -> if not, Eclipse is defaulting to Java 1.5 and you have classes implementing interface methods (which in Java 1.6 can be annotated with #Override, but in Java 1.5 can only be applied to methods overriding a superclass method).
You can also add Maven compiler plugin to your pom to make sure it is working with latest Java version:
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.3</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
Hope that causes an issue.