Java Reference
In-Depth Information
Example 18−11: web.xml
<?xml version="1.0" encoding="ISO-8859-1"?>
<!-- This is an xml file -->
<!-- This is document type of the xml file -->
<!DOCTYPE web-app
PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.2//EN"
"http://java.sun.com/j2ee/dtds/web-app_2.2.dtd">
<!-- Define configuration and deployment information for a web application -->
<web-app>
<!-- Each servlet tag defines information about a servlet. This one -->
<!-- defines a name for a specific Servlet implementation class. It maps -->
<!-- /servlet/hello (relative to the webapp root) to the specified class -->
<servlet>
<servlet-name>hello</servlet-name>
<servlet-class>com.davidflanagan.examples.servlet.Hello</servlet-class>
</servlet>
<!-- Here's another servlet tag. This one also defines initialization -->
<!-- parameters that the servlet reads in its init() method. -->
<servlet> <!-- The counter servlet -->
<servlet-name>counter</servlet-name>
<servlet-class>com.davidflanagan.examples.servlet.Counter</servlet-class>
<init-param>
<param-name>countfile</param-name> <!-- where to save state -->
<param-value>/tmp/counts.ser</param-value> <!-- adjust for your system-->
</init-param>
<init-param>
<param-name>saveInterval</param-name>
<!-- how often to save -->
<param-value>30000</param-value>
<!-- every 30 seconds -->
</init-param>
</servlet>
<servlet> <!-- The query servlet -->
<servlet-name>query</servlet-name>
<servlet-class>com.davidflanagan.examples.servlet.Query</servlet-class>
<!-- Configure all these init params for your database -->
<init-param>
<param-name>driverClassName</param-name> <!-- JDBC driver classname -->
<param-value>org.gjt.mm.mysql.Driver</param-value> <!-- mysql driver -->
</init-param>
<init-param>
<param-name>url</param-name> <!-- URL for the database -->
<param-value>jdbc:mysql://dbserver.my.domain.com/dbname</param-value>
</init-param>
<init-param>
<param-name>username</param-name>
<!-- Database username -->
<param-value>david</param-value>
</init-param>
<init-param>
<param-name>password</param-name>
<!-- Database password -->
<param-value>secret</param-value>
</init-param>
</servlet>
<!-- Note that you can define multiple named instances of a single -->
<!-- servlet class. If you have two different databases, for example, -->
<!-- you could define another instance of the Query servlet using a -->
<!-- with a different name and a different set of initialization params -->
<servlet> <!-- Another query servlet -->
