java - Tomcat include another xml file to web.xml

Question

Hello everyone,

Since I have lots of servlet mappings in my web.xml I was wondering if I could actually store all the mappings to separate file and then include it to web.xml.

servervlet-mapping.xml

<servlet>
    <servlet-name>red</servlet-name>
    <servlet-class>Test.Red</servlet-class>
</servlet>

<servlet-mapping>
    <servlet-name>red</servlet-name>
    <url-pattern>/blue</url-pattern>
</servlet-mapping>

<servlet>
    <servlet-name>blue</servlet-name>
    <servlet-class>Test.Blue</servlet-class>
</servlet>

<servlet-mapping>
    <servlet-name>blue</servlet-name>
    <url-pattern>/blue</url-pattern>
</servlet-mapping>

web.xml

<include file="servlet_mapping.xml"/>

This way it's possible to load xml files in struts.xml. (not sure if the same is possible in web.xml)

Is something like this possible? Or is there any other way to make it work?

(Apologies for my bad english)

Thanks in advance, Alex

Answer 1

Servlet 3.0 introduced the concept of web fragments, which addresses your question about splitting the web.xml into multiple files.These fragments can contain a portion (or all) of the web deployment descriptor by including a META-INF/web-fragment.xml

<web-fragment metadata-complete="true" version="3.0"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-fragment_3_0.xsd">
  <name>fragment1</name>
    <servlet>
        <servlet-name>red</servlet-name>
        <servlet-class>Test.Red</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>red</servlet-name>
        <url-pattern>/blue</url-pattern>
    </servlet-mapping>

    <servlet>
        <servlet-name>blue</servlet-name>
        <servlet-class>Test.Blue</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>blue</servlet-name>
        <url-pattern>/blue</url-pattern>
    </servlet-mapping>
</web-fragment>

in web.xml

...
    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
    </welcome-file-list>
    <servlet>
        <servlet-name>MyWelcomePage</servlet-name>
        <servlet-class>MyWelcomePage</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>MyWelcomePage</servlet-name>
        <url-pattern>/MyWelcomePage/*</url-pattern>
    </servlet-mapping>    
    <session-config>
        <session-timeout>30</session-timeout>
    </session-config>

    <absolute-ordering>
         <name>fragment1</name>
    </absolute-ordering>
</web-app>