title: RequestMapping cannot be resolved to a type
body: <p>I'm just starting to study Spring Boot. I installed STS and created an application with Web + JPA + MySQL + DevTools + Security. When I'm creating my Controller and I note it with @RequestMapping, STS says RequestMapping can not be resolved to a type.</p>
  
  <pre><code>import org.springframework.stereotype.Controller;
  
  @Controller
  public class TestController {
  
      @RequestMapping("/test")    
      public String test() {
          return "test";
      }
  
  }
  </code></pre>
  
  <p><strong>EDIT</strong></p>
  
  <p>My pom.xml</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  </code></pre>
  
  <p>http://maven.apache.org/xsd/maven-4.0.0.xsd">
      4.0.0</p>
  
  <pre><code>&lt;groupId&gt;com.heart&lt;/groupId&gt;
  &lt;artifactId&gt;echocardiogram&lt;/artifactId&gt;
  &lt;version&gt;0.0.1-SNAPSHOT&lt;/version&gt;
  &lt;packaging&gt;jar&lt;/packaging&gt;
  
  &lt;name&gt;echocardiogram&lt;/name&gt;
  &lt;description&gt;Echocardiogram Management System&lt;/description&gt;
  
  &lt;parent&gt;
      &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
      &lt;artifactId&gt;spring-boot-starter-parent&lt;/artifactId&gt;
      &lt;version&gt;2.0.1.RELEASE&lt;/version&gt;
      &lt;relativePath /&gt; &lt;!-- lookup parent from repository --&gt;
  &lt;/parent&gt;
  
  &lt;properties&gt;
      &lt;project.build.sourceEncoding&gt;UTF-8&lt;/project.build.sourceEncoding&gt;
      &lt;project.reporting.outputEncoding&gt;UTF-8&lt;/project.reporting.outputEncoding&gt;
      &lt;java.version&gt;1.8&lt;/java.version&gt;
  &lt;/properties&gt;
  
  &lt;dependencies&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
          &lt;artifactId&gt;spring-boot-starter-data-jpa&lt;/artifactId&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
          &lt;artifactId&gt;spring-boot-starter-security&lt;/artifactId&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
          &lt;artifactId&gt;spring-boot-starter-web&lt;/artifactId&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
          &lt;artifactId&gt;spring-boot-devtools&lt;/artifactId&gt;
          &lt;scope&gt;runtime&lt;/scope&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;mysql&lt;/groupId&gt;
          &lt;artifactId&gt;mysql-connector-java&lt;/artifactId&gt;
          &lt;scope&gt;runtime&lt;/scope&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
          &lt;artifactId&gt;spring-boot-starter-test&lt;/artifactId&gt;
          &lt;scope&gt;test&lt;/scope&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.springframework.security&lt;/groupId&gt;
          &lt;artifactId&gt;spring-security-test&lt;/artifactId&gt;
          &lt;scope&gt;test&lt;/scope&gt;
      &lt;/dependency&gt;
  &lt;/dependencies&gt;
  
  &lt;build&gt;
      &lt;plugins&gt;
          &lt;plugin&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-maven-plugin&lt;/artifactId&gt;
          &lt;/plugin&gt;
      &lt;/plugins&gt;
  &lt;/build&gt;
  </code></pre>
  
  <p></p>
  
  <p>How do I solve this?</p>