What is the use of filters in Web xml?

It allows you to declare servlet filters, which are aspects for HTTP requests. A filter chain can intercept an incoming request and/or an outgoing response and modify it as needed. A common example is to have a filter that performs a GZIP compression on a response stream if the user’s browser can accept it.

What is the use of context param in Web xml?

The “context-param” tag is define in “web. xml” file and it provides parameters to the entire web application. For example, store administrator’s email address in “context-param” parameter to send errors notification from our web application.

How are filters configured in Web xml?

You configure filters as part of a Web application, using the application’s web. xml deployment descriptor. In the deployment descriptor, you specify the filter and then map the filter to a URL pattern or to a specific servlet in the Web application. You can specify any number of filters.

Why do we need servlet filter?

Why do we have Servlet Filter? Servlet Filters are pluggable java components that we can use to intercept and process requests before they are sent to servlets and response after servlet code is finished and before container sends the response back to the client.

What is param name and param value in web XML?

The context-param element, subelement of web-app, is used to define the initialization parameter in the application scope. The param-name and param-value are the sub-elements of the context-param. The param-name element defines parameter name and and param-value defines its value.

How do we configure init params for JSP?

In JSP, config is an implicit object of type ServletConfig. This object can be used to get initialization parameter for a particular JSP page. The config object is created by the web container for each jsp page. Generally, it is used to get initialization parameter from the web.

What is a filter how servlet filter works give suitable example?

A Servlet filter is an object that can intercept HTTP requests targeted at your web application. A servlet filter can intercept requests both for servlets, JSP’s, HTML files or other static content, as illustrated in the diagram below: A Servlet Filter in a Java Web Application.

What do you mean by Filter explain with context to servlet with JSP?

The Java Servlet specification version 2.3 introduces a new component type, called a filter. A filter dynamically intercepts requests and responses to transform or use the information contained in the requests or responses. Second, filters can be used to transform the response from a servlet or a JSP page.

How does servlet filter work?

A Servlet filter is an object that can intercept HTTP requests targeted at your web application. When the servlet filter is loaded the first time, its init() method is called, just like with servlets. Just use the ServletResponse object to do so, just like you would inside a servlet. …

What do you mean by Filter explain the steps for implementing a filter with suitable example?

A filter is an object that is invoked at the preprocessing and postprocessing of a request. It is mainly used to perform filtering tasks such as conversion, logging, compression, encryption and decryption, input validation etc. The servlet filter is pluggable, i.e. its entry is defined in the web.

What is the optional context-Param element used for?

The optional context-param element contains the declaration of a Web application’s servlet context initialization parameters. The following table describes the reserved context parameters used by the Web application container, which have been deprecated and have replacements in weblogic.xml..

How to get context-param value in Java?

How to get context-param value in java? The “context-param” tag is define in “web.xml” file and it provides parameters to the entire web application. For example, store administrator’s email address in “context-param” parameter to send errors notification from our web application.

What is the difference between context parameters and init parameters?

Obviously, context parameters are introduced to store parameters that are used in several places while init parameters are associated to a specific web application servlet or filter. They are a great way to avoid the input of hard-coded values inside the code, but in the same time they are limited to simple key-value data representation.

What is the optional context-Param element of the httpclusterservlet class?

The optional context-param element contains the declaration of a Web application’s servlet context initialization parameters. This attribute specifies that certifications from clients of the Web application are provided in the special WL-Proxy-Client-Cert header sent by a proxy plug-in or HttpClusterServlet.