vim编写servlet，手动编译，手写web.xml

import java.io.*;
import jakarta.servlet.http.*;
import jakarta.servlet.*;

public class ExampleHttpServlet extends HttpServlet
{
        public void doPost(HttpServletRequest req, HttpServletResponse res)
        {
                try{
                        PrintWriter out = res.getWriter();
                        out.println("Hello World");
                } catch (Exception e){
                }
        }
}

手动编译

tomcat 环境下，手动编译javac版本与tomcat中的java版本要一致，否则可能会报错

javac --class-path /usr/local/tomcat/lib/servlet-api.jar ExampleHttpServlet.java

会生成一个ExampleHttpServlet.class

然后将class文件拷到tomcat下的webapps可以新建一个目录

目录结构如下

httptest
    └── WEB-INF
        ├── classes
        │   ├── ExampleHttpServlet.class
        │   └── ExampleHttpServlet.java
        ├── lib
        └── web.xml

手动编写web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="https://jakarta.ee/xml/ns/jakartaee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee
                      https://jakarta.ee/xml/ns/jakartaee/web-app_5_0.xsd"
  version="5.0"
  metadata-complete="true">

    <display-name>Servlet and JSP Examples</display-name>

    <request-character-encoding>UTF-8</request-character-encoding>



    <servlet>
        <servlet-name>test</servlet-name>
        <servlet-class>ExampleHttpServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>test</servlet-name>
        <url-pattern>/test</url-pattern>
    </servlet-mapping>

</web-app>

重启tomcat，通过http://localhost:8080/httptest/test访问成功