我不得不问你，因为我被卡住了，不能继续下去。我试图做这样的响应路径：
DAO-> Servlet-> JSP
过程是：用户在jsp上填写表单，单击“提交”并在同一JSP上获得响应（用户已添加或未添加）
将数据添加到数据库工作正常，但我从WebBrowser收到错误消息：
类型异常报告
邮件无法解析参数编号：pageContext.request.contextPath
描述服务器遇到意外情况，阻止其满足请求。
这是我的jsp代码：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix ="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix ="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
<%@ taglib prefix ="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<%@ page isELIgnored="false"%>
<script type="text/javascript" src="${pageContext.request.contextPath}/jQuery.js"/></script>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>dodaj pracownika</title>
</head>
<body>
<f:view>
<section id = registration" class = "section">
<div class "container tagline">
<em>{0}</em>
</div>
<br>
<AdContentProvider
Name="MIME-type"
Provider="addUser.class"
Properties="optional-properties-for-your-class"
>
</AdContentProvider>
<form action="${pageContext.request.contextPath}/newuser" method = "post">
<form>
<label> Imie</label> <input type="text" name= "imie" id="imie"> <br/>
<label> Nazwisko</label> <input type="text" name= "nazwisko" id="nazwisko"> <br/>
<label> Stanowisko</label> <input type="text" name= "stanowisko" id="stanowisko"> <br/>
<label> Stawka</label> <input type="text" name= "stawka" id="stawka"> <br/>
<input type ="submit" value="Dodaj" id = "dodaj">
</form>
</f:view>
</body>
</html>和Servlet代码：
package tk.jewsbar.servlets;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.text.MessageFormat;
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.transaction.Transactional;
import fasolki.Pracownik;
import tk.jewsbar.dao.Dao;
@WebServlet("/newuser")
public class addUser extends HttpServlet
{
@Override
@Transactional
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
{
String imie = req.getParameter("imie");
String nazwisko = req.getParameter("nazwisko");
String stanowisko = req.getParameter("stanowisko");
double stawka = Double.valueOf(req.getParameter("stawka"));
Pracownik pracownik = new Pracownik (imie, nazwisko, stanowisko, stawka);
Dao dao = new Dao();
int rows = dao.dodajUzytkownika(pracownik);
String err = "null";
if (rows ==0)
{
err = "Niestety nie udalo sie dodac uzytkownika";
}
else {
err = "Dodano uzytkownika" + rows;
}
String pejcz = getHTMLString(req.getServletContext().getRealPath("html/newuser.jsp"), err);
resp.getWriter().write(pejcz);
}
public String getHTMLString(String sciezka, String message) throws IOException
{
BufferedReader czytaj = new BufferedReader (new FileReader(sciezka));
String linia = "";
StringBuffer bufor = new StringBuffer();
while((linia=czytaj.readLine())!= null)
{
bufor.append(linia);
}
czytaj.close();
String pejcz = bufor.toString();
pejcz = MessageFormat.format(pejcz, message);
return pejcz;
}
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
String pejcz = getHTMLString(req.getServletContext().getRealPath("html/newuser.jsp"),"");
resp.getWriter().write(pejcz);
}
}
最佳答案
这样尝试
<script type="text/javascript" src="<c:out value="${contextPath}"/>/jQuery.js"></script>
要么
<script type="text/javascript" src="<c:out value="${pageContext.request.contextPath}"/>/jQuery.js"></script>
代替
<script type="text/javascript" src="${contextPath}/jQuery.js"/></script>
您可以阅读此链接上的建议，
expression-language-in-jsp-not-working
关于java - 在jsp上创建/显示servlet响应，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/52184324/