Tomcat configuration

Main files concerning tomcat configuration

On a deployed tomcat instance, these files can be found at /opt/tomcat/conf

references: tomcat docs

conf/
   - catalina.policy
   - catalina.properties
   - logging.properties
   - server.xml
   - tomcat-users.xml
   - web.xml
   - context.xml

server.xml

this is the main config file. located in the conf dir of installed tomcat configure Resources such as jdbc, messge brokers etc within GlobalNamingResources:

conf/
   - catalina.policy
   - catalina.properties
   - logging.properties
   - server.xml
   - tomcat-users.xml
   - web.xml
   - context.xml

server.xml

this is the main config file. located in the conf dir of installed tomcat configure Resources such as jdbc, messge brokers etc within GlobalNamingResources:

<Server ...
  ...
  <GlobalNamingResources>
    <Resource name="jdbc/db" auth="Container" type="javax.sql.DataSource"
              username="user"
              password="password"
              uri="jbdc:mysql://localhost:3306/db"
              ...
    />
  </GlobalNamingResources>
/Server>

web.xml

deployment descriptor for a web application. Defines servlets, filters and other components. during development typically located in WEB-INF dir

<web-app ...
  <display-name>my web app</display-name>

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

  <servlet>
    <servlet-name>MyAppServlet</servlet-name>
    <serlet-class>com.gallaghern.MyAppServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>MyAppServlet</servlet-name>
    <url-pattern>/myapplicationname</url-pattern>
  </servlet-mapping>

  <resource-ref>
    <res-ref-name>jdbc/db</res-ref-name>
    <res-type>javax.sql.DataSource</res-type>
    <res-auth>Container</res-auth>
  </resource-ref>

</web-app>

resource-ref element refers to the jdbc/db data source defined in server.xml

context.xml

defines database connections, JNDI resources and other configurations

There exists a server context and a context for each web application. The server context is found in the conf dir and is used to define global resources shared across many web applications.

An application context is located in the META-INF dir and is used to define resources specific to that application.

<Context>
  <Resouce name"jdbc/db"
    auth="Container"
    type="javax.sql.DataSource"
    driverClassName="com.mysql.jdbc.Driver"
    url="jdbc:mysql://localhost:3306/db"
    username="user"
    password="password"
    ...
  />
</Context>

The above context.xml contains a Resource element which specifies connection parameters for a mqsql database including jdbc driver class name, url, username, password and connection pooling settings.

A context.xml file might also detail a ResourceLink element:

<Context>
  <ResourceLink name="jdbc/db"
                global="jdbdc/db"
                type="javax.sql.DataSource"
  />
</Context>

which refers to an external resource called jdbc/db. global specifies the JNDI name of the resource - defined in the server context and referenced in the application context

catalina.properties

contains the global config settings located in conf dir

setenv.sh

set environment variables for tomcat. typically java options. located in bin dir

#!/bin/sh

export JAVA_OPTS="-xms512m -Xmx1024"

export CATALINA_OPTS="-Djava.awt.headless=true -Dfile.encoding=UTF-8"

...

logging.properties

defines log levels, log file location and log format

note

During development these files could be located in different locations depending on the codebase. Some options such as JDBC connectivity or runtime settings might be set programatically.