Jakarta Struts Cookbook

Chapter 2. Configuring Struts Applications

Introduction

Struts provides a flexible framework. It can be used in many different ways and supports customizations and extensions at several levels. As a result of this flexibility, many developers have difficulty understanding how to configure Struts to suit their purposes. Struts can be configured using the web application’s web.xml file as well as one or more Struts configuration files (struts-config.xml). In addition, the Struts Validator is configured through an additional set of XML files.

This chapter goes over some of the more common and not-so-common scenarios that utilize Struts configurability. The coverage includes creating plug-ins and is a simple, yet powerful mechanism that can be used to solve a number of problems. We will cover the use of multiple configuration files, for facilitating team development as well as structuring and partitioning the web application. Finally, we will review Struts’ built-in support for extensibility and the use of custom configuration properties.

2.1. Using Plug-ins for Application Initialization

Problem

You want to load initial data into the application context when your application starts up.

Solution

Create a class that implements the org.apache.struts.action.PlugIn interface and specify the plug-in element in the struts-config.xml. The following XML fragment shows a plug-in declaration and a nested set-property element for setting a custom property:

<plug-in className="com.oreilly.strutsckbk.CustomPlugin" ...