Some configuration details about servlet initial development

More comprehensive Detailed development servlet Explanations are included in each explanation video , Here are some of the details of my personal discovery ——

Servlet It can't run on its own , Need to be in a web Running in the application
And one web Applications are deployed in tomcat Medium
Its development environment choice IDEA Will be better Compared with eclipse It will be easier to operate

So develop a servlet The following steps are needed
establish web Application project That is to say web.xml file
To write servlet Code That is, create and write servlet Code class HelloServlet Inherited HttpServlet
And provides a doGet Method
Deploy to tomcat in （ This process needs to be understood alone tomcat Deployment is simple What we need to solve is the port problem and other exceptions ） An independent web The server Not dependent on others servlet The project needs it to run

The following is a personal screenshot ：
The whole thing is IDEA Layout ——

response.getWriter().println(""); The content in the is to run the page display

 <servlet-name>HelloServlet</servlet-name>
        <servlet-class>initial.HelloServlet</servlet-class>

Specify the... Of a specific class And its class name

<servlet-mapping>
        <servlet-name>HelloServlet</servlet-name>
        <url-pattern></url-pattern><!-- Here is the designated jump to   stay .java Class to display the contents of the page   If you do not press this button, the jump will only show index.jsp Of $end$-->
    </servlet-mapping>

url-pattern The function is to jump What is placed in this tab is the jump parameter After deployment, search in the browser write in "/ Parameter name " You can enter. Otherwise, as stated in the notes If there is nothing in this tag, this operation is not required