The taglib element has two subelements: taglib-uri and taglib-location. The taglib-uri element specifies a URI identifying a tag library that is used by the web application. The value may be either a relative or an absolute URI. The taglib-location element specifies the location as a resource of the tag library descriptor file. The Struts tag libraries are not the only ones that can be declared in the web application deployment descriptor.
If you create any of your own custom tag libraries, you should create taglib elements for them here as well. The welcome-file-list element allows you to configure default resources that should be used when a valid but partial URI is entered for a web application. You can specify multiple welcome files, and they will be used in the order in which they are listed.
Suppose we configured the welcome-file-list element for the Storefront application as in Example This is beneficial because most containers would, by default, look for index. You can specify multiple welcome-file elements within the welcome-file-list. This might be helpful if, for example, you deployed your application on various types of containers and the first welcome-file resource was not found on the server.
The container would continue to try to match the welcome files up to the request URI until it found one on the server and served that resource to the client. The order of the welcome file entries in the deployment descriptor is used for the matching process. If no welcome files are declared for the web application or the URI entered by a client, the web container may handle the request appropriately—for example, it may return a File Not Found error response or a directory listing.
However, there is an alternate way that allows you to achieve the same results. First, create a global forward in the Struts configuration file for the action that you would like to invoke:.
Then create a JSP page called welcome. The welcome. You then need to add a welcome-file element for the welcome. Containers using the welcome. The welcome forward in turn invokes the viewsignin. Although the Struts framework provides a suitable error-handling mechanism, there are times that problems slip through the exception-handling crack and users are shown a servlet or JSP exception.
To absolutely prevent this from happening, you should use the error-page element available to the web application deployment descriptor. Example shows a partial web. When an error status code is set in the response, the container consults the list of error-page declarations for the web application. If a match is found, the container returns the resource indicated by the location element. If you need to refer to a resource outside of the web application, you can use the HTML Refresh meta tag.
To do this, refer to a static HTML document in the location element that contains only the following line:. When the error occurs, the Refresh meta tag will reload immediately, but it will use the alternate URL provided. This strategy also is a good way to allow users to refer to resources with a static extension, such as. You might want to set the reload time to a value greater than zero. If processing has completed, it can forward to a completed page. A servlet also can generate exceptions for which you can declare error pages.
We define action tags corresponds to every URL we want to access and we define a class with execute method which will be accessed whenever we will access corresponding URL. Results determine what gets returned to the browser after an action is executed.
The string returned from the action should be the name of a result. Results are configured per-action as above, or as a "global" result, available to every action in a package. Results have optional name and type attributes. The default name value is "success". You could split the file into multiple xml files and import them in the following fashion.
The other configuration file that we haven't covered is the struts-default. This file contains the standard configuration settings for Struts and you would not have to touch these settings for For this reason, we are not going into too much detail on this file. If you are interested, take a look into the at the default.
The struts-config. Email Required, but never shown. The Overflow Blog. Does ES6 make JavaScript frameworks obsolete? Podcast Do polyglots have an edge when it comes to mastering programming Featured on Meta.
Now live: A fully responsive profile. Visit chat. Related Hot Network Questions. Question feed. This is a 'local' forward and is optional. Example Entry. In the above entry, when a request matching the specified path NetworkEvent is received, an instance of the ActionClass is created.
The controller looks for the bean in the specified scope request creating and saving a bean of the specified class, if needed. The ActionForward object is returned and the reference to the object is acquired using mapping.
The layout for the page displaying network events is defined in the corresponding tiles definition file, where the page components and the corresponding JSPs are specified.
0コメント