This question already has answers here:
javax.el.PropertyNotFoundException: Property 'foo' not found on type com.example.Bean
(5个答案)
3年前关闭。
我正在制作一个页面,您可以在其中更新,编辑,删除,插入数据库中的数据。插入页面运行良好,并且数据已成功插入,但是当我单击“添加”按钮时,我没有重定向到AllGrocery页面,但是Eclipse给了我这个错误。无法确定问题出在哪里。可以有人帮我吗?数据库:GroceryStore,表:杂货店(id,名称,价格)
DataAccess.java
DBUtils.java
杂货店
AllGrocery.java
AddNew.html
AllGrocery.jsp
ManagerAddNew.jsp
错误:
(5个答案)
3年前关闭。
我正在制作一个页面,您可以在其中更新,编辑,删除,插入数据库中的数据。插入页面运行良好,并且数据已成功插入,但是当我单击“添加”按钮时,我没有重定向到AllGrocery页面,但是Eclipse给了我这个错误。无法确定问题出在哪里。可以有人帮我吗?数据库:GroceryStore,表:杂货店(id,名称,价格)
DataAccess.java
package dao;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.LinkedList;
import java.util.List;
import com.sun.istack.internal.logging.Logger;
import db.DBUtils;
import model.Grocery;
public class DataAccess {
public void addNew(Grocery g) throws ClassNotFoundException, SQLException{
try {
PreparedStatement ps = DBUtils.getPreparedStatement("insert into grocerys values(?,?,?)");
ps.setInt(1, g.getID());
ps.setString(2, g.getName());
ps.setDouble(3, g.getPrice());
ps.executeUpdate();
} catch(ClassNotFoundException | SQLException ex){
}
}
public static List<Grocery> getAll(){
List<Grocery> gs = new LinkedList<>();
try {
ResultSet rs = DBUtils.getPreparedStatement("select * from grocerys").executeQuery();
while (rs.next()){
Grocery g = new Grocery();
g.setID(rs.getInt(1));
g.setName(rs.getString(2));
g.setPrice(rs.getDouble(3));
gs.add(g);
}
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return gs;
}
}
DBUtils.java
package db;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.Connection;
import java.sql.SQLException;
public class DBUtils {
public static PreparedStatement getPreparedStatement(String sql) throws ClassNotFoundException, SQLException{
PreparedStatement ps = null;
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/GroceryStore";
String user = "root";
String pass = "adil";
Connection conn = DriverManager.getConnection(url,user,pass);
ps = conn.prepareStatement(sql);
return ps;
}
public static void main(String[] args)throws ClassNotFoundException, SQLException {
getPreparedStatement("select * from grocerys");
}
}
杂货店
package model;
public class Grocery {
private int id;
private String name;
private Double price;
public void setID(int id_){
id = id_;
}
public void setName(String name_){
name = name_;
}
public void setPrice(Double price_){
price = price_;
}
public int getID(){
return id;
}
public String getName(){
return name;
}
public Double getPrice(){
return price;
}
}
AllGrocery.java
package servlet;
import java.io.IOException;
import javax.servlet.RequestDispatcher;
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 dao.DataAccess;
/**
* Servlet implementation class AllGrocery
*/
@WebServlet("/AllGrocery")
public class AllGrocery extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public AllGrocery() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setAttribute("AllGrocery", DataAccess.getAll());
RequestDispatcher rd = request.getRequestDispatcher("AllGrocery.jsp");
rd.forward(request, response);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
}
}
public Double getPrice(){
return price;
}
}
AddNew.html
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Add Grocery</title>
</head>
<body>
<h1>Add New Grocery</h1>
<form action = "ManagerAddNew.jsp" method = "post">
<table>
<tr>
<th>ID</th>
<td><input type = "number" name = "id" style = "width : 200px;"/></td>
</tr>
<tr>
<th>NAME</th>
<td><input type = "text" name = "name" style = "width : 200px;"/></td>
</tr>
<tr>
<th>PRICE</th>
<td><input type = "number" name = "price" style = "width : 200px;"/></td>
</tr>
<tr>
<th></th>
<td><input type = "submit" name = "submit" value = "ADD"/></td>
</tr>
</table>
</form>
</body>
</html>
AllGrocery.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ taglib prefix = "c" uri = "http://java.sun.com/jsp/jstl/core" %>
<!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=ISO-8859-1">
<title>Grocerys Available</title>
</head>
<body>
<div syle = "width : 1200px; margin-left:auto;margin-right:auto;">
<table cellpadding = "10">
<tr>
<th>ID</th>
<th>Name</th>
<th>Price</th>
</tr>
<c:forEach items = "${AllGrocery}" var = "p">
<tr>
<td>${p.id}</td>
<td>${p.name}</td>
<td>${p.price}</td>
<td>
<a href = "edit?id = ${p.id}">Edit</a>
<a href = "delete?id = ${p.id}">Delete</a>
</td>
</tr>
</c:forEach>
</table>
</div>
</body>
</html>
ManagerAddNew.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ page import = "model.Grocery" %>
<%@ page import = "dao.DataAccess" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<%
String name = request.getParameter("name");
int id = Integer.parseInt(request.getParameter("id"));
Double price = Double.parseDouble(request.getParameter("price"));
Grocery g = new Grocery();
g.setID(id);
g.setName(name);
g.setPrice(price);
DataAccess da = new DataAccess();
da.addNew(g);
response.sendRedirect("/SimpleServletProject/AllGrocery");
%>
</body>
</html>
错误:
org.apache.jasper.JasperException: An exception occurred processing JSP page /AllGrocery.jsp at line 29
26: <c:forEach items = "${AllGrocery}" var = "p">
27:
28: <tr>
29: <td>${p.id}</td>
30: <td>${p.name}</td>
31: <td>${p.price}</td>
32: <td>
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:575)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:477)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
servlet.AllGrocery.doGet(AllGrocery.java:38)
javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
javax.el.PropertyNotFoundException: Property 'id' not found on type model.Grocery
javax.el.BeanELResolver$BeanProperties.get(BeanELResolver.java:290)
javax.el.BeanELResolver$BeanProperties.access$300(BeanELResolver.java:243)
javax.el.BeanELResolver.property(BeanELResolver.java:377)
javax.el.BeanELResolver.getValue(BeanELResolver.java:97)
org.apache.jasper.el.JasperELResolver.getValue(JasperELResolver.java:104)
org.apache.el.parser.AstValue.getValue(AstValue.java:184)
org.apache.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:184)
org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:950)
org.apache.jsp.AllGrocery_jsp._jspx_meth_c_005fout_005f0(AllGrocery_jsp.java:215)
org.apache.jsp.AllGrocery_jsp._jspx_meth_c_005fforEach_005f0(AllGrocery_jsp.java:163)
org.apache.jsp.AllGrocery_jsp._jspService(AllGrocery_jsp.java:113)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:439)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
servlet.AllGrocery.doGet(AllGrocery.java:38)
javax.servlet.http.HttpServlet.service(HttpServlet.java:624)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
最佳答案
如果看到异常,则无法在Grocery对象中找到属性ID。您的ID的getter方法名称应更改为getId(),而不是getID()。它应该是getId(),因为当您camelCase时,您只是将变量的第一个字符更改为大写而不是整个变量。
10-08 13:25