Why web.xml

There you specify: what servlets and filters you want to use and what URLs you want to map them to listeners - classes that are notified when some events happen context starts, session created, etc configuration parameters context-params error pages, welcome files security constraints In servlet 3.

Improve this answer. Olimpiu POP 4, 3 3 gold badges 31 31 silver badges 46 46 bronze badges. Bozho Bozho k gold badges silver badges bronze badges. Michael Borgwardt Michael Borgwardt k 75 75 gold badges silver badges bronze badges. It says all the requests to go through WicketFilter Also, if you use wicket WicketApplication for application level settings. Nishant Nishant This does not really answer the why and what in the question. It's the default configuration for a Java web application; it's required.

I stumbled randomly upon this post. Correction: It WAS required. It is no longer required. Nine years later. Ravikumar Ravikumar 41 5 5 bronze badges. Accelerate startup and SMB growth with tailored solutions and programs. Get financial, business, and technical support to take your startup to the next level. Explore solutions for web hosting, app development, AI, and analytics. Build better SaaS products, scale efficiently, and grow your business.

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Tool to move workloads and existing applications to GKE. Service for executing builds on Google Cloud infrastructure. Traffic control pane and management for open service mesh. If no welcome file is specified, GlassFish Server will use a file named index.

If there is no welcome file and no file named index. You specify welcome files in the web. The welcome file specification for the hello1 example looks like this:. When an error occurs during execution of a web application, you can have the application display a specific error screen according to the type of error.

In particular, you can specify a mapping between the status code returned in an HTTP response or a Java programming language exception returned by any web component and any type of error screen. You can have multiple error-page elements in your deployment descriptor. Each element identifies a different error that causes an error page to open.

This error page can be the same for any number of error-page elements. In the Add Error Page dialog box, click Browse to locate the page that you want to act as the error page. To specify an error code, in the Error Code field enter the HTTP status code that will cause the error page to be opened, or leave the field blank to include all error codes.

To specify an exception type, in the Exception Type field enter the exception that will cause the error page to load. To specify all throwable errors and exceptions, enter java. If your web component uses such objects as enterprise beans, data sources, or web services, you use Java EE annotations to inject these resources into your application. Annotations eliminate a lot of the boilerplate lookup code and configuration elements that previous versions of Java EE required.

Although resource injection using annotations can be more convenient for the developer, there are some restrictions on using it in web applications. Double-click the web. The Developer Studio opens a multipage editor, which allows you to enter descriptions in the standard deployment descriptor web. These entries are automatically added to the XML source at the appropriate point. Choose the Mapping tab.

Select Servlet Mappings and choose Add. Servlet Name. URL Pattern. The following entries are automatically added to the XML source:. Choose the EJBs tab.