我正在尝试从 Eclipse 中的包运行一个 Web 应用程序，但无论我尝试什么，我仍然遇到这些错误。我还尝试阅读和理解错误日志报告，但这对我没有帮助，因为我对这一切都是新手
错误信息:
type Exception report
message An exception occurred processing JSP page /index.jsp at line 9
description The server encountered an internal error that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: An exception occurred processing JSP page /index.jsp at line 9
6: <title>SimpleJspServletDB</title>
7: </head>
8: <body>
9: <jsp:forward page="/UserController?action=listUser" />
10: </body>
11: </html>
它说第 9 行有问题，但这对我没有帮助。
这是我的 UserController.java 类
package com.daniel.controller;
import java.io.IOException;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.daniel.dao.UserDao;
import com.daniel.model.User;
public class UserController extends HttpServlet {
private static final long serialVersionUID = 1L;
private static String INSERT_OR_EDIT = "/user.jsp";
private static String LIST_USER = "/listUser.jsp";
private UserDao dao;
public UserController() {
super();
dao = new UserDao();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String forward="";
String action = request.getParameter("action");
if (action.equalsIgnoreCase("delete")){
int userId = Integer.parseInt(request.getParameter("userId"));
dao.deleteUser(userId);
forward = LIST_USER;
request.setAttribute("users", dao.getAllUsers());
} else if (action.equalsIgnoreCase("edit")){
forward = INSERT_OR_EDIT;
int userId = Integer.parseInt(request.getParameter("userId"));
User user = dao.getUserById(userId);
request.setAttribute("user", user);
} else if (action.equalsIgnoreCase("listUser")){
forward = LIST_USER;
request.setAttribute("users", dao.getAllUsers());
} else {
forward = INSERT_OR_EDIT;
}
RequestDispatcher view = request.getRequestDispatcher(forward);
view.forward(request, response);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
User user = new User();
user.setFirstName(request.getParameter("firstName"));
user.setLastName(request.getParameter("lastName"));
try {
Date dob = new SimpleDateFormat("MM/dd/yyyy").parse(request.getParameter("dob"));
user.setDob(dob);
} catch (ParseException e) {
e.printStackTrace();
}
user.setEmail(request.getParameter("email"));
String userid = request.getParameter("userid");
if(userid == null || userid.isEmpty())
{
dao.addUser(user);
}
else
{
user.setUserid(Integer.parseInt(userid));
dao.updateUser(user);
}
RequestDispatcher view = request.getRequestDispatcher(LIST_USER);
request.setAttribute("users", dao.getAllUsers());
view.forward(request, response);
}
}
还有我的 DD web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
<display-name>SimpleJspServletDB</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<servlet>
<description></description>
<display-name>UserController</display-name>
<servlet-name>UserController</servlet-name>
<servlet-class>com.daniel.controller.UserController</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>UserController</servlet-name>
<url-pattern>/UserController</url-pattern>
</servlet-mapping>
</web-app>
还有我的index.jsp
<%@ page language="java" contentType="text/html; charset=EUC-KR" pageEncoding="EUC-KR"%>
<!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=EUC-KR">
<title>SimpleJspServletDB</title>
</head>
<body>
<jsp:forward page="/UserController?action=listUser" />
</body>
</html>
最佳答案
在 servlet 的 doGet 和 doPost 方法中使用 try-catch block ，并在 catch block ，以便您可以准确地知道 servlet 失败的位置。
关于java - HTTP 状态 500 - 在第 9 行处理 JSP page/index.jsp 时发生异常，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15206016/