Jsp找不到java类（服务器遇到意外情况，无法满足请求）
我是JavaEE、servlet和jsp的初学者。最近，我开始着手我的第一个java ee项目，在使用servlet时出现了以下错误： 这些是我的包裹： CategoryHelper（它返回类别对象）Jsp找不到java类（服务器遇到意外情况，无法满足请求）,java,jsp,servlets,Java,Jsp,Servlets,我是JavaEE、servlet和jsp的初学者。最近，我开始着手我的第一个java ee项目，在使用servlet时出现了以下错误： 这些是我的包裹： CategoryHelper（它返回类别对象） 包模型； 导入org.hibernate.Session； 导入org.hibernate.SessionFactory； 导入org.hibernate.query.query； 导入java.util.List； 公共类类别帮助器{ 私人会话工厂； 公共类别帮助器（）{ MySession
包模型；
导入org.hibernate.Session；
导入org.hibernate.SessionFactory；
导入org.hibernate.query.query；
导入java.util.List；
公共类类别帮助器{
私人会话工厂；
公共类别帮助器（）{
MySessionFactory=SessionFactoryProvider.getSessionFactory（）；
}
公共列表getCategories（）{
会话s=MySessionFactory.openSession（）；
Query Query=s.createQuery（“来自CategoryClass”）；
返回query.list（）；
}
}
package servlet;
import model.CategoryClass;
import model.CategoryHelper;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;
public class MyFirstServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
CategoryHelper categoryHelper = new CategoryHelper();
List<CategoryClass> Categorieslist = categoryHelper.getCategories();
request.setAttribute("categories", Categorieslist);
request.getRequestDispatcher("servlet/web/header.jsp").forward(request,response);
}
}
<!DOCTYPE html>
<html lang="en">
<head>
<% request.setCharacterEncoding("UTF-8"); %>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta charset="UTF-8">
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Welcome</title>
<base href=".">
<meta name="description"
content="A free shopping cart system. OpenCart is an open source">
<link href="Resources/bootstrap.css" rel="stylesheet">
<link href="Resources/stylesheet.css" rel="stylesheet">
<link href="Resources/font-awesome.min.css" rel="stylesheet">
<link href="Resources/bootstrap-datetimepicker.min.css" type="text/css" rel="stylesheet" media="screen">
<script type="text/javascript" async="" src="Resources/analytics.js.download"></script>
<script src="Resources/jquery-1.12.2.min.js.download"></script>
<script src="Resources/bootstrap.min.js.download"></script>
<script src="Resources/moment.js.download" type="text/javascript"></script>
<script src="Resources/bootstrap-datetimepicker.min.js.download" type="text/javascript"></script>
<script src="Resources/common.js.download"></script>
<script async="" src="Resources/js"></script>
<script>
window.dataLayer = window.dataLayer || [];
function gtag() {
dataLayer.push(arguments);
}
gtag('js', new Date());
gtag('config', 'UA-1988725-1');
</script>
</head>
<body>
<header>
<jsp:include page="header.jsp"/>
</header>
<div id="common-home">
<div id="hero">
<div class="container">
<div class="row">
<jsp:include page="searchbar.html"/>
<div class="col-xs-12 col-md-7">
<h1>Looking For New And Used Books Online?</h1>
<p>Search, Find And Enjoy Reading The Book...</p>
<p class="hidden-xs"><a href="https://www.opencart.com/index.php?route=cms/download"
class="btn btn-success btn-xl">Free Download</a> <a
href="https://www.opencart.com/index.php?route=cms/demo" class="btn btn-white btn-xl">View
Demo</a></p>
<p class="visible-xs-block"><a href="https://www.opencart.com/index.php?route=cms/download"
class="btn btn-success btn-lg btn-block">Free Download</a> <a
href="https://www.opencart.com/index.php?route=cms/demo"
class="btn btn-white btn-lg btn-block">View Demo</a></p>
</div>
</div>
<div class="hidden-md hidden-lg"><img src="Resources/hero-image.png"
alt="The best FREE and open-source eCommerce platform"
title="The best FREE and open-source eCommerce platform"
class="img-responsive"></div>
</div>
<div class="device hidden-xs hidden-sm"><img src="Resources/hero-image.png"
alt="The best FREE and open-source eCommerce platform"
title="The best FREE and open-source eCommerce platform"
class="hidden"></div>
</div>
<br>
<div id="feature" class="container" style="padding-top: 0px">
<div class="page-header text-center">
<h2>Simple to Search. Easy to Buy.</h2>
<p>Start Searching Based On Your Favorite Genre!</p>
</div>
<div class="row visible-sm-block">
<div class="col-sm-6">
<h4><i class="opencart-icon-opencart-open-source-and-free"></i>
<div>Open-source and Free</div>
</h4>
<p>Open source means transparent. OpenCart comes with free downloads and updates. Zero monthly fees.</p>
</div>
<div class="col-sm-6">
<h4><i class="opencart-icon-opencart-powerful-store-management"></i>
<div>Powerful Store Management</div>
</h4>
<p>Benefit from our built-in SEO. Easy manage products, customers, orders, taxes rules, coupon codes and
more.</p>
</div>
</div>
<div class="row visible-sm-block">
<div class="col-sm-6">
<h4><i class="opencart-icon-opencart-extension-and-themes"></i>
<div>Extension and Themes</div>
</h4>
<p>The biggest eCommerce selections of modules and themes to expand your store functionality.</p>
</div>
<div class="col-sm-6">
<h4><i class="opencart-icon-opencart-support-you-can-trust-on"></i>
<div>Support You Can Trust On</div>
</h4>
<p>We’ve got you covered. OpenCart offers free community or dedicated commercial support.</p>
</div>
</div>
</div>
<div id="marketplace" class="container">
<div class="row">
<div class="col-md-6" style="padding-top: 0px">
<h2>Best Place For Book Worms.<br>
Find Special And Mysterious Books HERE.</h2>
<p>"Books are the quietest and most constant of friends; they are the most accessible and wisest of counselors, and the most patient of teachers."
<br>Charles W. Eliot</p>
<div class="hidden-xs hidden-sm"><a
href="https://www.opencart.com/index.php?route=marketplace/extension"
class="btn btn-primary btn-xl">Visit Marketplace</a></div>
<div class="text-center visible-xs-block visible-sm-block"><a
href="https://www.opencart.com/index.php?route=marketplace/extension"
class="btn btn-primary btn-lg btn-block">Visit Marketplace</a></div>
</div>
<div class="col-md-6"><img src="Resources/g1.png" class="img-responsive"></div>
</div>
</div>
<div id="business" class="container-fluid">
<div class="container">
<div class="page-header">
<h2>From corporations to local businesses</h2>
<p>OpenCart powers over 342 000 eCommerce Entrepreneurs all over the world</p>
</div>
</div>
</div>
<div id="support" class="container text-center">
<div class="page-header">
<h2>Support based on your needs</h2>
<p>OpenCart offers Community or Dedicated Support</p>
</div>
<div class="row">
<div class="col-sm-6"><img src="Resources/community-support-icon.png" alt="Community Support"
title="Community Support">
<h2>Community Support</h2>
<p>OpenCart forums is a great way to get community support. With more than 110 000 registered members
and 550 000+ posts you are part of one of the biggest ecommerce communities</p>
<p>
<a href="http://forum.opencart.com/" class="btn btn-primary btn-lg hidden-xs">Learn More</a>
<a href="http://forum.opencart.com/" class="btn btn-primary btn-lg btn-block visible-xs">Learn
More</a>
</p>
</div>
<div class="col-sm-6"><img src="Resources/dedicated-support-icon.png" alt="Dedicated Support"
title="Dedicated Support">
<h2>Dedicated Support</h2>
<p>OpenCart offers dedicated technical support. The service is great for anyone who wants to get
professional technical support for their OpenCart project right from the source.</p>
<p>
<a href="https://dedicated.opencart.com/" target="_blank" class="btn btn-primary btn-lg hidden-xs">Learn
More</a>
<a href="https://dedicated.opencart.com/" target="_blank"
class="btn btn-primary btn-lg btn-block visible-xs">Learn More</a>
</p>
</div>
</div>
</div>
<div id="press" class="container-fluid">
<div class="container">
</div>
</div>
</div>
<jsp:include page="footer.html"/>
<script type="text/javascript"><!--
if (typeof (Zenbox) !== "undefined") {
Zenbox.init({
dropboxID: "20269606",
url: "https://opencart.zendesk.com",
tabTooltip: "Support",
tabImageURL: "https://assets.zendesk.com/external/zenbox/images/tab_support.png",
tabColor: "black",
tabPosition: "Left"
});
}
//--></script>
</body>
</html>
包servlet；
导入model.CategoryClass；
导入model.CategoryHelper；
导入javax.servlet.ServletException；
导入javax.servlet.http.HttpServlet；
导入javax.servlet.http.HttpServletRequest；
导入javax.servlet.http.HttpServletResponse；
导入java.io.IOException；
导入java.util.List；
公共类MyFirstServlet扩展了HttpServlet{
受保护的void doPost（HttpServletRequest请求、HttpServletResponse响应）引发ServletException、IOException{
}
受保护的void doGet（HttpServletRequest请求，HttpServletResponse响应）抛出ServletException，IOException{
CategoryHelper CategoryHelper=新的CategoryHelper（）；
List Categorieslist=categoryHelper.getCategories（）；
setAttribute（“categories”，Categorieslist）；
getRequestDispatcher（“servlet/web/header.jsp”）.forward（请求、响应）；
}
}
<!DOCTYPE html>
<html lang="en">
<head>
<% request.setCharacterEncoding("UTF-8"); %>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<meta charset="UTF-8">
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Welcome</title>
<base href=".">
<meta name="description"
content="A free shopping cart system. OpenCart is an open source">
<link href="Resources/bootstrap.css" rel="stylesheet">
<link href="Resources/stylesheet.css" rel="stylesheet">
<link href="Resources/font-awesome.min.css" rel="stylesheet">
<link href="Resources/bootstrap-datetimepicker.min.css" type="text/css" rel="stylesheet" media="screen">
<script type="text/javascript" async="" src="Resources/analytics.js.download"></script>
<script src="Resources/jquery-1.12.2.min.js.download"></script>
<script src="Resources/bootstrap.min.js.download"></script>
<script src="Resources/moment.js.download" type="text/javascript"></script>
<script src="Resources/bootstrap-datetimepicker.min.js.download" type="text/javascript"></script>
<script src="Resources/common.js.download"></script>
<script async="" src="Resources/js"></script>
<script>
window.dataLayer = window.dataLayer || [];
function gtag() {
dataLayer.push(arguments);
}
gtag('js', new Date());
gtag('config', 'UA-1988725-1');
</script>
</head>
<body>
<header>
<jsp:include page="header.jsp"/>
</header>
<div id="common-home">
<div id="hero">
<div class="container">
<div class="row">
<jsp:include page="searchbar.html"/>
<div class="col-xs-12 col-md-7">
<h1>Looking For New And Used Books Online?</h1>
<p>Search, Find And Enjoy Reading The Book...</p>
<p class="hidden-xs"><a href="https://www.opencart.com/index.php?route=cms/download"
class="btn btn-success btn-xl">Free Download</a> <a
href="https://www.opencart.com/index.php?route=cms/demo" class="btn btn-white btn-xl">View
Demo</a></p>
<p class="visible-xs-block"><a href="https://www.opencart.com/index.php?route=cms/download"
class="btn btn-success btn-lg btn-block">Free Download</a> <a
href="https://www.opencart.com/index.php?route=cms/demo"
class="btn btn-white btn-lg btn-block">View Demo</a></p>
</div>
</div>
<div class="hidden-md hidden-lg"><img src="Resources/hero-image.png"
alt="The best FREE and open-source eCommerce platform"
title="The best FREE and open-source eCommerce platform"
class="img-responsive"></div>
</div>
<div class="device hidden-xs hidden-sm"><img src="Resources/hero-image.png"
alt="The best FREE and open-source eCommerce platform"
title="The best FREE and open-source eCommerce platform"
class="hidden"></div>
</div>
<br>
<div id="feature" class="container" style="padding-top: 0px">
<div class="page-header text-center">
<h2>Simple to Search. Easy to Buy.</h2>
<p>Start Searching Based On Your Favorite Genre!</p>
</div>
<div class="row visible-sm-block">
<div class="col-sm-6">
<h4><i class="opencart-icon-opencart-open-source-and-free"></i>
<div>Open-source and Free</div>
</h4>
<p>Open source means transparent. OpenCart comes with free downloads and updates. Zero monthly fees.</p>
</div>
<div class="col-sm-6">
<h4><i class="opencart-icon-opencart-powerful-store-management"></i>
<div>Powerful Store Management</div>
</h4>
<p>Benefit from our built-in SEO. Easy manage products, customers, orders, taxes rules, coupon codes and
more.</p>
</div>
</div>
<div class="row visible-sm-block">
<div class="col-sm-6">
<h4><i class="opencart-icon-opencart-extension-and-themes"></i>
<div>Extension and Themes</div>
</h4>
<p>The biggest eCommerce selections of modules and themes to expand your store functionality.</p>
</div>
<div class="col-sm-6">
<h4><i class="opencart-icon-opencart-support-you-can-trust-on"></i>
<div>Support You Can Trust On</div>
</h4>
<p>We’ve got you covered. OpenCart offers free community or dedicated commercial support.</p>
</div>
</div>
</div>
<div id="marketplace" class="container">
<div class="row">
<div class="col-md-6" style="padding-top: 0px">
<h2>Best Place For Book Worms.<br>
Find Special And Mysterious Books HERE.</h2>
<p>"Books are the quietest and most constant of friends; they are the most accessible and wisest of counselors, and the most patient of teachers."
<br>Charles W. Eliot</p>
<div class="hidden-xs hidden-sm"><a
href="https://www.opencart.com/index.php?route=marketplace/extension"
class="btn btn-primary btn-xl">Visit Marketplace</a></div>
<div class="text-center visible-xs-block visible-sm-block"><a
href="https://www.opencart.com/index.php?route=marketplace/extension"
class="btn btn-primary btn-lg btn-block">Visit Marketplace</a></div>
</div>
<div class="col-md-6"><img src="Resources/g1.png" class="img-responsive"></div>
</div>
</div>
<div id="business" class="container-fluid">
<div class="container">
<div class="page-header">
<h2>From corporations to local businesses</h2>
<p>OpenCart powers over 342 000 eCommerce Entrepreneurs all over the world</p>
</div>
</div>
</div>
<div id="support" class="container text-center">
<div class="page-header">
<h2>Support based on your needs</h2>
<p>OpenCart offers Community or Dedicated Support</p>
</div>
<div class="row">
<div class="col-sm-6"><img src="Resources/community-support-icon.png" alt="Community Support"
title="Community Support">
<h2>Community Support</h2>
<p>OpenCart forums is a great way to get community support. With more than 110 000 registered members
and 550 000+ posts you are part of one of the biggest ecommerce communities</p>
<p>
<a href="http://forum.opencart.com/" class="btn btn-primary btn-lg hidden-xs">Learn More</a>
<a href="http://forum.opencart.com/" class="btn btn-primary btn-lg btn-block visible-xs">Learn
More</a>
</p>
</div>
<div class="col-sm-6"><img src="Resources/dedicated-support-icon.png" alt="Dedicated Support"
title="Dedicated Support">
<h2>Dedicated Support</h2>
<p>OpenCart offers dedicated technical support. The service is great for anyone who wants to get
professional technical support for their OpenCart project right from the source.</p>
<p>
<a href="https://dedicated.opencart.com/" target="_blank" class="btn btn-primary btn-lg hidden-xs">Learn
More</a>
<a href="https://dedicated.opencart.com/" target="_blank"
class="btn btn-primary btn-lg btn-block visible-xs">Learn More</a>
</p>
</div>
</div>
</div>
<div id="press" class="container-fluid">
<div class="container">
</div>
</div>
</div>
<jsp:include page="footer.html"/>
<script type="text/javascript"><!--
if (typeof (Zenbox) !== "undefined") {
Zenbox.init({
dropboxID: "20269606",
url: "https://opencart.zendesk.com",
tabTooltip: "Support",
tabImageURL: "https://assets.zendesk.com/external/zenbox/images/tab_support.png",
tabColor: "black",
tabPosition: "Left"
});
}
//--></script>
</body>
</html>
欢迎
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推送（参数）；
}
gtag（'js'，新日期（））；
gtag（“配置”、“UA-1988725-1”）；
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