SSL in Tomcat

First Create Certificate file (key store) by using java 'keytool" command utility.

Change the underlined words to suit you.

Second, copy the 'cert.cer' file into tomcat/conf.

Third, modify the 'server.xml' file in conf folder like this below:

<Connector port="8443" protocol="HTTP/1.1" SSLEnabled="true"
               maxThreads="150" scheme="https" secure="true"
               clientAuth="false" sslProtocol="TLS" keystore="conf/cert.cer" keypass="phucnt123"/>

Fourth, edit your web.xml file in tomcat/conf and add the following inside of your container element:     
<!-- Require HTTPS for everything except /img (favicon) and /css. -->
    <security-constraint>
        <web-resource-collection>
            <web-resource-name>HTTPSOnly</web-resource-name>
            <url-pattern>/*</url-pattern>
        </web-resource-collection>
        <user-data-constraint>
            <transport-guarantee>CONFIDENTIAL</transport-guarantee>
        </user-data-constraint>
    </security-constraint>
    <security-constraint>
        <web-resource-collection>
            <web-resource-name>HTTPSOrHTTP</web-resource-name>
            <url-pattern>*.ico</url-pattern>
            <url-pattern>/img/*</url-pattern>
            <url-pattern>/css/*</url-pattern>
        </web-resource-collection>
        <user-data-constraint>
            <transport-guarantee>NONE</transport-guarantee>
        </user-data-constraint>
    </security-constraint>
 
Now, start Tomcat and run your web application, you will see your web application will run with HTTPS.

That's it!