When using servlets to build the HTML, you build a DOCTYPE line, why do you do that? | Java Servlets

I know all major browsers ignore it even though the HTML 3.2 and 4.0 specifications require it. But building a DOCTYPE line tells HTML validators which version of HTML you are using so they know which specification to check your document against. These validators are valuable debugging services, helping you catch HTML syntax errors.

What is filter? Can filter be used as request or response? | Java Servlets

A filter is a reusable piece of code that can transform the content of HTTP requests,responses, and header information. Filters do not generally create a response or respond to a request as servlets do, rather they modify or adapt the requests for a resource, and modify or adapt responses from a resource.

If a servlet is not properly initialized, what exception may be thrown? | Java Servlets

During initialization or service of a request, the servlet instance can throw an UnavailableException or a ServletException.

When a client request is sent to the servlet container, how does the container choose which servlet to invoke? | Java Servlets

The servlet container determines which servlet to invoke based on the configuration of its servlets, and calls it with objects representing the request and response.

What is servlet container? | Java Servlets

The servlet container is a part of a Web server or application server that provides the network services over which requests and responses are sent, decodes MIME-based requests, and formats MIME-based responses. A servlet container also contains and manages servlets through their lifecycle.

Why is Servlet so popular? | Java Servlets

Because servlets are platform-independent Java classes that are compiled to platform-neutral byte code that can be loaded dynamically into and run by a Java technology-enabled Web server.

What is Java Servlet? | Java Servlets

A servlet is a Java technology-based Web component, managed by a container called servlet container or servlet engine, that generates dynamic content and interacts with web clients via a request/response paradigm.