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This article will explain in detail how to analyze the basic structure of Servlet. The content of the article is of high quality, so the editor will share it for you as a reference. I hope you will have a certain understanding of the relevant knowledge after reading this article.

The following code shows a simple Servlet basic structure. The Servlet deals with GET requests, the so-called GET requests. If you are not familiar with HTTP, think of it as a request made by the browser when the user enters URL in the browser address bar, clicks on the link in the Web page, and submits a form that does not specify METHOD. Servlet can also easily handle POST requests. A POST request is a request made when submitting a form that specifies METHOD= "POST".

Import java.io.*; import javax.servlet.*; import javax.servlet.http.* Public class SomeServlet extends HttpServlet {public void doGet (HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {/ / use "request" to read information related to the request (such as Cookies) / and form data / / use "response" to specify the HTTP reply status code and answer header / / (such as specify content type, set Cookie) PrintWriter out = response.getWriter () / / use "out" to send the reply to the browser}}

Servlet basic structure, if a class is going to be Servlet, it should inherit from HttpServlet, overriding one or all of the doGet or doPost methods, depending on whether the data is sent through GET or POST. Both the doGet and doPost methods have two parameters, which are the HttpServletRequest type and the HttpServletResponse type. HttpServletRequest provides methods to access information about the request, such as form data, HTTP request headers, and so on. In addition to providing methods for specifying HTTP reply status (200404, etc.), response headers (Content-Type,Set-Cookie, etc.), HttpServletResponse provides a PrintWriter for sending data to the client. For a simple Servlet, most of its work is to generate pages sent to the client through println statements.

Notice that doGet and doPost throw two exceptions, so you must include them in the declaration. In addition, you must import the java.io package (to use classes such as PrintWriter), the javax.servlet package (to use classes such as HttpServlet), and the javax.servlet.http package (to use the HttpServletRequest class and HttpServletResponse class).

Finally, the doGet and doPost methods are called by the service method, and sometimes you may need to override the service method directly.

On how to analyze the basic structure of Servlet to share here, I hope that the above content can be of some help to you, can learn more knowledge. If you think the article is good, you can share it for more people to see.

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