JavaServer Pages, 3rd Edition

Dispatching Requests to an Action Class

The second requirement for using a Controller servlet is that the servlet must be able to distinguish requests for different types of actions. The Struts servlet uses a configuration file with mappings from a part of the request path to the corresponding action class to handle this. The file is named struts-config.xml and is located in the WEB-INF directory for the application by default. Example 19-8 shows the configuration file used for the Project Billboard application.

Example 19-8. Struts configuration file

<?xml version="1.0" encoding="ISO-8859-1" ?>
  
<!DOCTYPE struts-config PUBLIC
  "-//Apache Software Foundation//DTD Struts Configuration 1.0//EN"
  "http://jakarta.apache.org/struts/dtds/struts-config_1_0.dtd">
  
<struts-config>
  <global-forwards>
    <forward name="login" path="/ch19/login.jsp" redirect="true" />
    <forward name="main" path="/ch19/protected/main.jsp" 
       redirect="true" />
  </global-forwards>
  
  <action-mappings>
    <action path="/ch19/authenticate"
      type="com.ora.jsp.servlets.AuthenticateAction" />
    <action path="/ch19/logout"
      type="com.ora.jsp.servlets.LogoutAction" />
    <action path="/ch19/protected/storeMsg"
      type="com.ora.jsp.servlets.StoreMsgAction" />
    <action path="/ch19/protected/updateProfile"
      type="com.ora.jsp.servlets.UpdateProfileAction" />
  </action-mappings>
</struts-config>

It’s an XML file, as are most configuration files nowadays. The first part of the file defines what Struts calls global forward mappings. I’ll get back to them ...