在idea中建立web專案

1）建立一個普通的Java專案

2）右鍵專案選擇ADD Framework Support

 3）勾選JavaEE

4）新增jar包

點選Project Structure

 5）部署Tomcat

 配置專案訪問路徑

 在Web工程中編寫Servlet

在src下建立HelloServlet.java

package www.servlet;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
 
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;

public class HelloServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        PrintWriter pw
 
=resp.getWriter();
        pw.println("HelloServlet");
        pw.flush();
        pw.close();
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doGet(req,resp);
    }
}

在web.xml對該servlet進行配置

<?xml version="1.0" encoding="UTF-8"
 
?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <!--為servlet取名-->
    <servlet>
        <servlet-name>servlet1</servlet-name>
        <servlet-class>www.servlet.HelloServlet</servlet-class>
    </servlet>
    <!--做URL對映-->
    <servlet-mapping>
        <servlet-name>servlet1</servlet-name>
        <url-pattern>/helloservlet</url-pattern>
    </servlet-mapping>
</web-app>

啟動Tomcat