title: HTTP ERROR 503: can not access /. Reason Service Unavailable
body: <p>My code is in github</p>
  
  <pre><code>https://github.com/shiblybcc/blog-aggregator
  </code></pre>
  
  <p>I have just created a spring framework project. This is my web.xml file code</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xmlns="http://java.sun.com/xml/ns/javaee"
      xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
      version="3.0"&gt;
      &lt;display-name&gt;Course Rating&lt;/display-name&gt;
      &lt;welcome-file-list&gt;
          &lt;welcome-file&gt;index.html&lt;/welcome-file&gt;
          &lt;welcome-file&gt;index.htm&lt;/welcome-file&gt;
          &lt;welcome-file&gt;index.jsp&lt;/welcome-file&gt;
          &lt;welcome-file&gt;default.html&lt;/welcome-file&gt;
          &lt;welcome-file&gt;default.htm&lt;/welcome-file&gt;
          &lt;welcome-file&gt;default.jsp&lt;/welcome-file&gt;
      &lt;/welcome-file-list&gt;
  &lt;/web-app&gt;
  </code></pre>
  
  <p>After I run my jetty server this works perfect and show the content of index.jsp file. But if I add following code in the web.xml file</p>
  
  <pre><code>&lt;servlet&gt;
      &lt;servlet-name&gt;dispatcher&lt;/servlet-name&gt;
      &lt;servlet-class&gt;org.springframework.web.servlet.DispatcherServlet&lt;/servlet-class&gt;
      &lt;load-on-startup&gt;1&lt;/load-on-startup&gt;
  &lt;/servlet&gt;
  
  &lt;servlet-mapping&gt;
      &lt;servlet-name&gt;dispatcher&lt;/servlet-name&gt;
      &lt;url-pattern&gt;*.html&lt;/url-pattern&gt;
      &lt;url-pattern&gt;*.htm&lt;/url-pattern&gt;
      &lt;url-pattern&gt;*.json&lt;/url-pattern&gt;
      &lt;url-pattern&gt;*.xml&lt;/url-pattern&gt;
  &lt;/servlet-mapping&gt;
  </code></pre>
  
  <p>I get the error </p>
  
  <pre><code>HTTP ERROR: 503    
  Problem accessing /. Reason:    
      Service Unavailable
  </code></pre>
  
  <p>I am following a tutorial and they are doing the same. I don't understand what is wrong with my code. Thanks in advance.</p>