Strange behavior of server.port property in Tomcat

Question

Actually, it is not a problem, but a strange thing I would like to understand. I use SpringBoot2 with embedded Tomcat. And I've added self-signed SSL certificate. This is pretty usual config:

server.ssl.key-store-type=PKCS12
server.ssl.key-store=classpath:keystore.p12
server.ssl.key-store-password=123456
server.ssl.key-alias=tomcat
server.port=8443

And I made a connector, to force http -> https redirect, like in many examples:

private Connector getHttpConnector() {
        Connector connector = new Connector("org.apache.coyote.http11.Http11NioProtocol");
        connector.setScheme("http");
        connector.setPort(8080);
        connector.setSecure(false);
        connector.setRedirectPort(8443);
        return connector;
    }

If I would not specify server.port property in my config, I will see the following error:

Description:

The Tomcat connector configured to listen on port 8080 failed to start. The port may already be in use or the connector may be misconfigured.

Action:

Verify the connector's configuration, identify and stop any process that's listening on port 8080, or configure this application to listen on another port.

But if I will, I will see following:

o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8443 (https) 8080 (http) with context path ''

Why server.port starts to point at https port??? Even sources of springframework.boot.autoconfigure.web.ServerProperties says that it is

/**
 * Server HTTP port.
 */

Is it ok, or I've got something strange in my server? Or this is how Conectors works? :) Thank you

sandeep sandeep · Accepted Answer · 2018-08-23T06:43:57

By default, the embedded server start on port 8080 if you don't give any value for server.port in the properties file And you are also specifying connectors port as 8080 (connector.setPort(8080);) Hence you are getting port conflicts.

Strange behavior of server.port property in Tomcat

1 Answers