eclipseでtomcatを起動するとエラーが出ます

前提・実現したいこと

最近javaの学習を始めた者です。
macでeclipseを使ってjavaのコードを書いているのですが、tomcatを起動しようとするとえらーが出て起動できません。何故エラーになるのでしょうか。
エラーコードについても調べてみたのですが原因がよく分かりません。

コードに関しては、フォームで入力した内容をデータベースに保存するコードのつもりです。
データベースにアクセスする部分が複数のクラスで共用したかったので親クラスとして切り分けています。

発生している問題・エラーメッセージ

重大: Begin イベントで例外を送出しました。 [月 11月 16 20:01:11 JST 2020]
java.lang.NoClassDefFoundError: javax/servlet/http/HttpServletRequest
	at java.base/java.lang.ClassLoader.defineClass1(Native Method)
	at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1016)
	at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:151)
	at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(BuiltinClassLoader.java:825)
	at java.base/jdk.internal.loader.BuiltinClassLoader.findClassOnClassPathOrNull(BuiltinClassLoader.java:723)
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(BuiltinClassLoader.java:646)
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:604)
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:168)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
	at java.base/java.lang.Class.getDeclaredMethods0(Native Method)
	at java.base/java.lang.Class.privateGetDeclaredMethods(Class.java:3325)
	at java.base/java.lang.Class.privateGetPublicMethods(Class.java:3350)
	at java.base/java.lang.Class.getMethods(Class.java:1996)
	at org.apache.tomcat.util.IntrospectionUtils.findMethods(IntrospectionUtils.java:406)
	at org.apache.tomcat.util.IntrospectionUtils.setProperty(IntrospectionUtils.java:70)
	at org.apache.tomcat.util.digester.SetPropertiesRule.begin(SetPropertiesRule.java:104)
	at org.apache.tomcat.util.digester.Digester.startElement(Digester.java:1293)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(AbstractSAXParser.java:518)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(AbstractXMLDocumentParser.java:183)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanStartElement(XMLDocumentFragmentScannerImpl.java:1386)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2725)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:605)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:541)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:888)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:824)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1224)
	at java.xml/com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:635)
	at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1551)
	at org.apache.catalina.startup.Catalina.parseServerXml(Catalina.java:617)
	at org.apache.catalina.startup.Catalina.load(Catalina.java:709)
	at org.apache.catalina.startup.Catalina.load(Catalina.java:746)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:64)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:564)
	at org.apache.catalina.startup.Bootstrap.load(Bootstrap.java:302)
	at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:472)
Caused by: java.lang.ClassNotFoundException: javax.servlet.http.HttpServletRequest
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:606)
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:168)
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:522)
	... 38 more

該当のソースコード

java
1<%@ page language="java" contentType="text/html; charset=UTF-8"
2    pageEncoding="UTF-8"%>
3<!DOCTYPE html>
4<html>
5<head>
6<meta charset="UTF-8">
7<title>Insert title here</title>
8<link rel="stylesheet" href="lib/style.css">
9</head>
10<body>
11<form action="database/InsertCustomer" method = "POST">
12<table>
13<tr>
14<th align="right">名前：</th>
15<td><input type="text" name="name" size=35 maxlength="20"></td>
16</tr>
17<tr>
18<th align="right">emailアドレス：</th>
19<td><input type="text" name="email" size=35 maxlength="50"></td>
20</tr>
21<tr>
22<th align="right">パスワード：</th>
23<td><input type="password" name="password" size=35 minlength="8" maxlength="15"></td>
24</tr>
25<tr>
26<th align="right">住所：</th>
27<td><input type="text" name="adress" size=35 maxlength="20"></td>
28</tr>
29<tr>
30<th align="right">電話番号：</th>
31<td><input type="tel" name="tel" size=35 maxlength="10"></td>
32</tr>
33<tr>
34<td colspan="2"><input type="submit" value="登録"></td>
35</table>
36</form>
37</body>
38</html>

java
1package database;
2
3import java.sql.Connection;
4import java.sql.DriverManager;
5import java.sql.SQLException;
6
7import javax.servlet.annotation.WebServlet;
8import javax.servlet.http.HttpServlet;
9
10/**
11 * Servlet implementation class BaseServlet
12 */
13@WebServlet("/database/BaseServlet")
14public class BaseServlet extends HttpServlet {
15
16	public Connection getConnection() {
17		Connection con = null;
18		String url = "jdbc:mariadb://localhost:3306/customer";
19		String user = "root";
20		String pass = "root";
21		try {
22			con = DriverManager.getConnection(user, pass, url);
23		} catch(SQLException e) {
24			e.printStackTrace();
25		} catch(Exception e) {
26			e.printStackTrace();
27		}
28		return con;
29	}
30
31}
32

java
1package database;
2
3import java.io.IOException;
4import java.sql.Connection;
5import java.sql.PreparedStatement;
6import java.sql.SQLException;
7
8import javax.servlet.ServletException;
9import javax.servlet.annotation.WebServlet;
10import javax.servlet.http.HttpServlet;
11import javax.servlet.http.HttpServletRequest;
12import javax.servlet.http.HttpServletResponse;
13
14/**
15 * Servlet implementation class InsertCustomer
16 */
17@WebServlet("/database/InsertCustomer")
18public class InsertCustomer extends BaseServlet {
19	/**
20	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
21	 */
22	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
23		// TODO Auto-generated method stub
24		PreparedStatement statement = null;
25		Connection con = null;
26		String sql = "INSERT INTO customer (name, email, password, adress, tel) VALUES(?,?,?,?,?)";
27		try {
28			con = super.getConnection();
29			statement = con.prepareStatement(sql);
30			statement.setString(1, request.getParameter("name"));
31			statement.setString(2, request.getParameter("email"));
32			statement.setString(3, request.getParameter("password"));
33			statement.setString(4, request.getParameter("adress"));
34			statement.setString(5, request.getParameter("tel"));
35			statement.executeUpdate();
36		} catch(SQLException e) {
37			e.printStackTrace();
38		} catch(Exception e) {
39			e.printStackTrace();
40		} finally {
41			try {
42				if(statement != null) {con.close();}
43				if(con != null) {con.close();}
44			} catch(Exception e) {
45				e.printStackTrace();
46			}
47		}
48	}
49
50}
51

java
1<?xml version="1.0" encoding="UTF-8"?>
2<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" id="WebApp_ID" version="4.0">
3  <display-name>shopinf</display-name>
4  <welcome-file-list>
5  <welcome-file>entryCustomer.jsp</welcome-file>
6    <welcome-file>index.html</welcome-file>
7    <welcome-file>index.htm</welcome-file>
8    <welcome-file>index.jsp</welcome-file>
9    <welcome-file>default.html</welcome-file>
10    <welcome-file>default.htm</welcome-file>
11  </welcome-file-list>
12
13  <servlet>
14  <servlet-name>BassServlet</servlet-name>
15  <servlet-class>database.BaseServlet</servlet-class>
16  </servlet>
17  <servlet-mapping>
18  <servlet-name>BassServlet</servlet-name>
19  <url-pattern>/database/BaseServlet</url-pattern>
20  </servlet-mapping>
21  <servlet>
22  <servlet-name>InsertCustomer</servlet-name>
23  <servlet-class>database.InsertCustomer</servlet-class>
24  </servlet>
25  <servlet-mapping>
26  <servlet-name>InsertCustomer</servlet-name>
27  <url-pattern>/database/InsertCustomer</url-pattern>
28  </servlet-mapping>
29</web-app>