Code works with Embedded Apache Tomcat 8 but not with 9. What's changed?

Question

Embedding Apache Tomcat into an eclipse web app project.
The code works when I\'m using the latest Tomcat 8 (8.0.5 Embedded) jars as dependencies, and this server respon

Answer 1

It looks like you haven't added a Connector to your embedded server. Tomcat 9 no longer automatically adds a Connector to your server for you, so you'll have to trigger it yourself:

package app;

import org.apache.catalina.LifecycleException;
import org.apache.catalina.startup.Tomcat;

public class Main {

    public static void main(String[] args) {

        Tomcat tomcat = new Tomcat();
        tomcat.setPort(8080);
        tomcat.getConnector(); // Trigger the creation of the default connector

        try {
            tomcat.start();
        } catch (LifecycleException e) {
            e.printStackTrace();
        }

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

It's worth mentioning that adding a call to tomcat.getConnector() should be safe for previous versions of Tomcat as well, so this need not be a "Tomcat 9-only" thing.