Servlets must run in a Java Web server environment.
The Java Web server is a special server that can parse and execute Java servlet code. Common Java Web servers include Apache Tomcat Jetty, IBM WebSphere, etc.
The Java Web server provides a servlet container (also known as a servlet engine) for loading, initializing, and managing servlet components. It is also responsible for processing the client request and returning the response to the client.
When deploying a Java Web application, you need to package the written servlet components into a WAR (Web Application Archive) file and deploy the WAR file to the Java Web server. The server will automatically parse the WAR file, and load and manage the servlet components in it.
Therefore, in order to make the servlet run normally, it needs to be deployed and run in a Java Web server environment that supports the Java Servlet specification. Only in this environment, Servlets can receive HTTP requests from clients and generate corresponding HTTP responses.
