How to run different apps on single Tomcat instance behind different ports?

Currently I have 2 web applications app1 and app2 running on Tomcat 6:

• app1 on http://localhost:8080/app1
• app2 on http://localhost:8080/app2

I want to configure Tomcat so that they run in root context behind separate ports:

• app1 on http://localhost:8081
• app2 on http://localhost:8082

What needs to be done?

I think you can configure that in you server.xml file and put 2 services :

<Service name="app1">
   <Connector port="8081" protocol="org.apache.coyote.http11.Http11NioProtocol" 
           connectionTimeout="20000" 
           redirectPort="8443" />
   <Engine name="Catalina" defaultHost="localhost">
      <Host name="localhost"  appBase="app1"
        unpackWARs="true" autoDeploy="true">
      </Host>
   </Engine>
</Service>
<Service name="app2">
   <Connector port="8082" protocol="org.apache.coyote.http11.Http11NioProtocol" 
           connectionTimeout="20000" 
           redirectPort="8443" />
   <Engine name="Catalina" defaultHost="localhost">
      <Host name="localhost"  appBase="app2"
        unpackWARs="true" autoDeploy="true">
      </Host>
   </Engine>
</Service>

Another example of adding connectors:

<Service name="reciver">
    <Connector port="8080" maxHttpHeaderSize="8192" maxThreads="10" 
               enableLookups="false" acceptCount="100"
               connectionTimeout="10000" disableUploadTimeout="true" 
               useBodyEncodingForURI="true"/>
    <Engine name="reciver" defaultHost="localhost" jvmRoute="host1">
            <Realm className="org.apache.catalina.realm.UserDatabaseRealm"
                   resourceName="UserDatabase" />
            <Host name="localhost" appBase="webapps" unpackWARs="true"
                  autoDeploy="false" xmlValidation="false"
                  xmlNamespaceAware="false">
                    <Context docBase="browser" path="/browser" reloadable="false"/>
            </Host>
    </Engine>
</Service>
<Service name="reciver2">
    <Connector port="8081" maxHttpHeaderSize="8192" maxThreads="10" 
               enableLookups="false" acceptCount="1"
               connectionTimeout="10000" disableUploadTimeout="true" 
               useBodyEncodingForURI="true" proxyName="example.pt" proxyPort="80"/>
    <Engine name="reciver2" defaultHost="example_app" jvmRoute="host2">
            <Host name="example_app" appBase="test_app/example_app" unpackWARs="true"
                  autoDeploy="false" xmlValidation="false"
                  xmlNamespaceAware="false">
                    <Context docBase="example_app" path="/example_app" reloadable="false"/>
            </Host>
    </Engine>
</Service>
(...Repeted 2 more times.)

Taken from: http://www.coderanch.com/t/84172/Tomcat/listen-multiple-ports

I recommend reading the whole thread, as it talks about performance hits with this configuration, and also possible race conditions.

Besides running two Tomcat instances and using ROOT application (that has already been said and is a bit poor and ineffective solution) you can achieve it by using Apache + Tomcat. Configuring apache to listen to both ports and forward by IP:Port to different Tomcat applications. But you need a different port por tomcat!

Apache configuration

listen 8080,8081
...
<VirtualHost *:8080>
    ServerName localhost
    ProxyPass / http://localhost:8888/app1
    ProxyPassReverse / http://localhost:8080/app1
</VirtualHost>

<VirtualHost *:8081>
    ServerName localhost
    ProxyPass / http://localhost:8888/app2
    ProxyPassReverse / http://localhost:8080/app2
</VirtualHost>

or

listen 80,81
...
<VirtualHost *:80>
    ServerName localhost
    ProxyPass / http://localhost:8080/app1
    ProxyPassReverse / http://localhost:8080/app1
</VirtualHost>

<VirtualHost *:81>
    ServerName localhost
    ProxyPass / http://localhost:8080/app2
    ProxyPassReverse / http://localhost:8080/app2
</VirtualHost>

Use two different Tomcat instances.

EDIT:

Or configure Tomcat as explained in the answer of this question: https://stackoverflow.com/questions/4719616/tomcat-configuration-help-multiple-ports-not-responding

Tomcat runs on the ports specified in:

$CATALINA_HOME/conf/server.xml

As JB Nizet wrote, setup two different instances of tomcat, and configure the port value server.xml appropriately.

$CATALINA_HOME/tomcat-8081/conf/server.xml:

<?xml version='1.0' encoding='utf-8'?>
 <Server port="8081" ... >
  ...
 </Server>

$CATALINA_HOME/tomcat-8082/conf/server.xml:

<?xml version='1.0' encoding='utf-8'?>
 <Server port="8082" ... >
  ...
 </Server>

I am using IntelliJ and I added a line in the application.properties file and it worked: for web app 1's project add: server.port = 8081 for web app 2's project add: server.port = 8082