JavaEE/Tomcat 9.0.0/IntellijIdea 2016.2 : At least one JAR was scanned for TLDs yet contained no TLDs

Question

错误

启动应用程序时出现问题。它提示:

org.apache.jasper.servlet.TldScanner.scanJars At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.

有一个link to screenshot output

一些源文件:

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
          http://java.sun.com/xml/ns/javaee/web-app_3_1.xsd"
           version="3.1">

    <resource-ref>
        <description>DB Connection</description>
        <res-ref-name>jdbc/users</res-ref-name>
        <res-type>javax.sql.DataSource</res-type>
        <res-auth>Container</res-auth>
    </resource-ref>

    <context-param>
        <param-name>javax.faces.CONFIG_FILES</param-name>
        <param-value>/WEB-INF/context.xml</param-value>
    </context-param>
    <servlet>
        <servlet-name>Faces Servlet</servlet-name>
        <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>Faces Servlet</servlet-name>
        <url-pattern>*.xhtml</url-pattern>
    </servlet-mapping>
</web-app>

context.xml

<?xml version="1.0" encoding="UTF-8"?>
<Context>
    <Resource name="jdbc/users"
              global="jdbc/users"
              auth="Container"
              type="javax.sql.DataSource"
              username="root"
              password="admin"
              driverClassName="com.mysql.jdbc.Driver"
              url="jdbc:mysql://localhost:3306/users" />
</Context>

InputServlet

package pl.javastart.prepared.servlet;

import java.io.IOException;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.naming.Context;
import javax.naming.InitialContext;
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 javax.sql.DataSource;

@WebServlet("/InputServlet")
public class InputServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request,
                         HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    protected void doPost(HttpServletRequest request,
                          HttpServletResponse response) throws ServletException, IOException {

        Connection conn = null;
        ResultSet resultSet = null;
        Statement statement = null;

        try {
            Context initialContext = new InitialContext();
            Context envContext = (Context) initialContext
                    .lookup("java:comp/env");
            DataSource ds = (DataSource) envContext.lookup("jdbc/users");
            conn = ds.getConnection();

            statement = conn.createStatement();
            String username = request.getParameter("username");
            String password = request.getParameter("password");
            // pass2" OR '1'='1'; --
            final String sqlQuery = "SELECT username, password FROM user WHERE "
                    +"username=" + "\"" + username + "\" "
                    +"AND "
                    +"password=" + "\"" + password + "\";";
            System.out.println(sqlQuery);
            resultSet = statement.executeQuery(sqlQuery);

            if(resultSet.next()) {
                String userFound = resultSet.getString("username");
                request.getSession().setAttribute("username", userFound);
                if("admin".equals(userFound)) {
                    request.getSession().setAttribute("privigiles", "all");
                } else{
                    request.getSession().setAttribute("privigiles", "view");
                }
            } else {
                request.getSession().setAttribute("username", "Nieznajomy");
                request.getSession().setAttribute("privigiles", "none");
            }
            request.getRequestDispatcher("result.jsp").forward(request, response);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                resultSet.close();
                statement.close();
                conn.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

}

结果.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Insert title here</title>
</head>
<body>
<h1>Welcome <%= session.getAttribute("username") %></h1>
<h2>Your privigiles: <%= session.getAttribute("privigiles") %></h2>
</body>
</html>

index.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
  <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
  <title>Log in</title>
</head>
<body>
<h1>Log in</h1>
<form action="InputServlet" method="post">
  <input type="text" placeHolder="Username" name="username">
  <br>
  <input type="password" placeHolder="Password" name="password">
  <br>
  <input type="submit" value="Zaloguj">
</form>
</body>
</html>

旧版本 Tomcat 的解决方案在这里不起作用

Answer 1

在 web.xml 中添加 servlet 映射:

<servlet>
    <servlet-name>InputServlet</servlet-name>
    <servlet-class>pl.javastart.prepared.servlet.InputServlet</servlet-class>
</servlet>
<servlet-mapping>
    <servlet-name>InputServlet</servlet-name>
    <url-pattern>/*</url-pattern>
</servlet-mapping>