Scala Cookbook

15.6. Replacing XML Servlet Mappings with Scalatra Mounts

Problem

You want to add new servlets to your Scalatra application, and need to know how to add them, including defining their URI namespace.

Solution

Scalatra provides a nice way of getting you out of the business of declaring your servlets and servlet mappings in the web.xml file. Simply create a boilerplate web.xml file like this in the src/main/webapp/WEB-INF directory:

<?xml version="1.0" encoding="UTF-8"?>
<web-app 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-app_3_0.xsd"
      version="3.0">
    <listener>
      <listener-class>org.scalatra.servlet.ScalatraListener</listener-class>
    </listener>

    <servlet-mapping>
      <servlet-name>default</servlet-name>
      <url-pattern>/img/*</url-pattern>
      <url-pattern>/css/*</url-pattern>
      <url-pattern>/js/*</url-pattern>
      <url-pattern>/assets/*</url-pattern>
    </servlet-mapping>
</web-app>

Next, assuming that you’re working with the application created in Recipe 15.5, edit the src/main/scala/ScalatraBootstrap.scala file so that it has these contents:

import org.scalatra._
import javax.servlet.ServletContext
import com.alvinalexander.app._

class ScalatraBootstrap extends LifeCycle {
  override def init(context: ServletContext) {

    // created by default
    context.mount(new MyScalatraServlet, "/*")

    // new
    context.mount(new StockServlet, "/stocks/*")
    context.mount(new BondServlet, "/bonds/*" ...