CODEWITHSUNDEEP
servletsembedded-tomcat-8
Benny Code
Benny Code

Reputation: 54812

@WebServlet annotation doesn't work with Tomcat 8

I want to use the @WebServlet annotation in a Java EE webapp which runs on Tomcat 8.

I have read that I need to declare Servlet Version 3.1 in my web.xml and that my Servlet needs to extend HttpServlet. I did all that but still the @WebServlet doesn't work. I am getting a HTTP 404.

I also tried my configuration with metadata-complete="false" in my web.xml, but still no success.

Here is my web.xml and Servlet.

The complete sample code can be found on GitHub.

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app 
  version="3.1" 
  xmlns="http://xmlns.jcp.org/xml/ns/javaee" 
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
  xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd">

  <context-param>
    <param-name>facelets.DEVELOPMENT</param-name>
    <param-value>true</param-value>
  </context-param>

  <!-- http://stackoverflow.com/a/7924117/451634 -->
  <!-- Put "-1" to disable this feature -->
  <context-param>
    <param-name>facelets.REFRESH_PERIOD</param-name>
    <param-value>1</param-value>
  </context-param>

  <servlet>
    <servlet-name>Faces Servlet</servlet-name>
    <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
  </servlet>

  <servlet-mapping>
    <servlet-name>Faces Servlet</servlet-name>
    <url-pattern>*.xhtml</url-pattern>
  </servlet-mapping>

  <welcome-file-list>
    <welcome-file>index.xhtml</welcome-file>
  </welcome-file-list>

  <!-- JSF -->
  <listener>
    <listener-class>org.apache.myfaces.webapp.StartupServletContextListener</listener-class>
  </listener>   

  <!-- CDI -->
  <listener>
    <listener-class>org.apache.webbeans.servlet.WebBeansConfigurationListener</listener-class>
  </listener>

</web-app>

TestServlet.java

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet(name = "TestServlet", urlPatterns = {"*.serve"})
public class TestServlet extends HttpServlet {

  @Override
  protected void doGet(HttpServletRequest req, HttpServletResponse resp)
          throws ServletException, IOException {
    try (ServletOutputStream out = resp.getOutputStream()) {
      out.write("Hello World".getBytes());
      out.flush();
    }
  }

}

Upvotes: 15

Views: 31168

Answers (5)

Akhil Panwar
Akhil Panwar

Reputation: 11

Using @WebServlet<"/name"> instead of @WebServlet<"name"> might work.

Upvotes: 0

Spiff Jekey-Green
Spiff Jekey-Green

Reputation: 327

You might want to change the lib you're using, like from javax to jakarta

<!-- https://mvnrepository.com/artifact/jakarta.servlet/jakarta.servlet-api -->
<dependency>
    <groupId>jakarta.servlet</groupId>
    <artifactId>jakarta.servlet-api</artifactId>
    <version>6.0.0</version>
    <scope>provided</scope>
</dependency>

Then change all javax.* imports to jakarta.*

Upvotes: 1

Mahbub Ul Islam
Mahbub Ul Islam

Reputation: 1059

Check out your javax.servlet version.

Make sure it's 3 or plus.

If not, change it to the latest one.

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>4.0.1</version>
    <scope>provided</scope>
</dependency>

Upvotes: 0

agelbess
agelbess

Reputation: 4351

How about @ServletComponentScan?

Example from http://www.baeldung.com/spring-servletcomponentscan

@ServletComponentScan
@SpringBootApplication
public class SpringBootAnnotatedApp {
    public static void main(String[] args) {
        SpringApplication.run(SpringBootAnnotatedApp.class, args);
    }
}

Upvotes: -2

Benny Code
Benny Code

Reputation: 54812

I got it working. I had to extend the way I started my Tomcat 8.0.12 server.

Nevertheless, there are three main things that must be done:

  1. web-app version in web.xml has to be at least 3.0 (I used 3.1)
  2. metadata-complete in web.xml may not be true (default is "false")
  3. classes directories have to be added to the embedded Tomcat before start

Here is an example for the web.xml file:

<?xml version="1.0" encoding="UTF-8"?>
<web-app 
  version="3.1" 
  metadata-complete="false"  
  xmlns="http://xmlns.jcp.org/xml/ns/javaee" 
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
  xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd">

  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
  </welcome-file-list>

</web-app>

This is how my Tomcat main class looks like (which supports now @WebServlet annotations):

public static void main(String[] args) throws Exception {
  String contextPath = "/";
  String webappDirLocation = "src/main/webapp/";
  String baseDirectory = new File(webappDirLocation).getAbsolutePath();

  Tomcat tomcat = new Tomcat();
  tomcat.setPort(8080);
  StandardContext context = (StandardContext) tomcat.addWebapp(contextPath, baseDirectory);

  // Additions to make @WebServlet work
  String buildPath = "target/classes";
  String webAppMount = "/WEB-INF/classes";

  File additionalWebInfClasses = new File(buildPath);
  WebResourceRoot resources = new StandardRoot(context);
  resources.addPreResources(new DirResourceSet(resources, webAppMount, additionalWebInfClasses.getAbsolutePath(), contextPath));
  context.setResources(resources);
  // End of additions

  tomcat.start();
  tomcat.getServer().await();
}

Upvotes: 25

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