xml配置servlet；500，404问题
tomcat 9.0
jdk17.0
eclipse 2019
页面跳转先报错500和刷新404，弄了一天实在没辙了，各位看看什么问题：
目录结构：
初始页面：
500页面：
404页面：
NewFile.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<form action="RegServlet" method="post">
<table>
<tr>
<td>用户名：</td>
<td><input type="text" name="username"></td>
</tr>
<tr>
<td>密 码：</td>
<td><input type="password" name="password"></td>
</tr>
<tr>
<td>性别：</td>
<td><input type="radio" name="sex" value="男" checked>男
<input type="radio" name="sex" value="女">女
</td>
</tr>
<tr>
<td>说 明：</td>
<td><textarea name="note" rows=3 cols=30></textarea></td>
</tr>
<tr>
<td><input type="submit" value="提交" name="submit"></td>
<td><input type="reset" value="重置" name="reset"></td>
</tr>
</table>
</form>
</body>
</html>
RegServlet.java
package servlet;
import java.io.IOException;
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 reg.Register;
/**
* Servlet implementation class RegServlet
*/
@WebServlet("RegServlet")
public class RegServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public RegServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
Register register = new Register();
response.setCharacterEncoding("utf-8");
register.execute(request, response.getWriter());
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
System.out.println("=======");
Register register = new Register();
response.setCharacterEncoding("utf-8");
register.execute(request, response.getWriter());
}
}
Register.java
package reg;
import java.io.PrintWriter;
import java.io.UnsupportedEncodingException;
import javax.servlet.http.HttpServletRequest;
public class Register {
private String username;
private String password;
private String sex;
private String note;
public void execute(HttpServletRequest request,PrintWriter out) {
try {
request.setCharacterEncoding("UTF-8");
username=request.getParameter("username");
password=request.getParameter("password");
sex=request.getParameter("sex");
note=request.getParameter("note");
out.print("用户名："+username+"<br>");
out.print("密码："+password+"<br>");
out.print("性别："+sex+"<br>");
out.print("信息："+note+"<br>");
out.print("<br>");
out.print("<a href='./NewFile.jsp'>返回</a>");
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
web.xml
```xml
<?xml version="1.0" encoding="UTF-8"?>
<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">
<display-name>test01</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>RegServlet</servlet-name>
<servlet-class>servlet.RegServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>RegServlet</servlet-name>
<url-pattern>/RegServlet</url-pattern>
</servlet-mapping>
</web-app>
```
