使用IDEA创建WebServlet

1.新建

 

 

 

2.创建java,resources,classes,lib目录

 

 3.project structure

 

 

 

 

 

 

 

修改Artifacts后为

 

 4.加入tomcat中

 

  

 

 5.在src中创建helloworld.java

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

@WebServlet("/helloworld")
public class helloworld extends HttpServlet {
    private String message;

    @Override
    public void init() throws ServletException {
        message = "Hello world, this message is from servlet!";
    }

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //设置响应内容类型
        resp.setContentType("text/html");

        //设置逻辑实现
        PrintWriter out = resp.getWriter();
        out.println("<h1>" + message + "</h1>");
    }

    @Override
    public void destroy() {
        super.destroy();
    }
}

6.修改web.xml

<?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">
    <servlet>
        <servlet-name>helloworld</servlet-name>
        <servlet-class>helloworld</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>helloworld</servlet-name>
        <url-pattern>/helloworld</url-pattern>
    </servlet-mapping>
</web-app>

7.启动tomcat,访问

 

 8.说明:1.输出目录一定要改到classes中，不然找不到访问地址，lib中是存入的jar包的。