BrandDao.java
package dao;
import java.util.List;
import model.pojo.Brands;
import model.util.HibernateUtil;
import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
public class BrandDao {
public static List<Brands> list() {
List<Brands> brands = null;
try {
Session session = HibernateUtil.getSessionFactory().openSession();
Query query = session.createQuery("from Brands");
brands = query.list();
session.close();
}
catch (HibernateException ex) {
ex.printStackTrace();
}
return brands;
}
public Brands getBrandById(int brandId) {
SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
Brands brand = (Brands) session.get(Brands.class, brandId);
tx.commit();
session.close();
return brand;
}
public Brands addBrand(Brands brand) {
try {
SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
session.save(brand);
tx.commit();
session.close();
} catch (HibernateException ex) {
ex.printStackTrace();
}
return brand;
}
}
BrandsController.java
package controller;
import dao.BrandDao;
import java.io.IOException;
import java.util.List;
import model.pojo.Brands;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.ModelAndView;
@Controller
public class BrandsController {
ModelAndView mav = new ModelAndView();
@RequestMapping(value="/admin/brands")
public ModelAndView index() {
List<Brands> brands = BrandDa.list();
mav.addObject("brands", brands);
mav.setViewName("brands-admin");
return mav;
}
@RequestMapping(value="/admin/brands/add", method = RequestMethod.POST)
public String addBrand(@RequestParam("photo") MultipartFile photo, @RequestParam("brandName") String name) throws IOException {
Brands brand = new Brands();
BrandDao brandDao = new BrandDa();
byte[] photoBytes = photo.getBytes();
brand.setBrandLogo(photoBytes);
brand.setBrandName(name);
brandDao.addBrand(brand);
return "redirect:/admin/brands";
}
@RequestMapping(value="/admin/brands/getBrand", method = RequestMethod.GET)
@ResponseBody
public Brands getBrand(int brandId) {
BrandDao brandDao = new BrandDa();
return brandDao.getBrandById(brandId);
}
}
brands-admin.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<%@taglib prefix="form" uri="http://www.springframework.org/tags/form"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>House of Beauty</title>
<link rel="stylesheet" href="${pageContext.request.contextPath}/resources/css/styles.css" />
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
<script src="https://code.jquery.com/jquery-3.4.0.min.js"></script>
<script>
$(document).ready(function() {
$('#getBrand').on('click', function(event) {
event.preventDefault();
var href = $(this).attr('href');
$.get(href, function(brand, status) {
$('#BrandForm #name').val(brand.getBrandName());
$('#BrandForm #photo').val(brand.getBrandLogo());
});
$('#BrandForm').modal('show');
});
});
</script>
</head>
<body>
<div class="modal fade" id="BrandForm" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header">
<h5 class="modal-title w-100" id="myModalLabel">Edit brand</h5>
<button type="button" class="close" data-dismiss="modal" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
</div>
<div class="modal-body">
<form method="post" enctype="multipart/form-data" action="${pageContext.request.contextPath}/admin/brands/update">
<div class="form-group">
<input type="text" name="brandName" id="name" placeholder="Name" cssClass="form-control"/>
</div>
<div class="form-group">
<input type="file" name="photo" id="photo"/>
</div>
<div class="row form-bottom">
<div class="col">
<input type="submit" value="Save" class="btn" id="btnAdd">
<input type="submit" value="Delete" class="btn" id="btnAdd">
</div>
</div>
<form>
</div>
</div>
</div>
</div>
<div class="modal fade" id="AddBrandForm" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header">
<h5 class="modal-title w-100" id="myModalLabel">Add brand</h5>
<button type="button" class="close" data-dismiss="modal" aria-label="Close">
<span aria-hidden="true">×</span>
</button>
</div>
<div class="modal-body">
<form method="post" enctype="multipart/form-data" action="${pageContext.request.contextPath}/admin/brands/add">
<div class="form-group">
<input type="text" name="brandName" placeholder="Name" cssClass="form-control"/>
</div>
<div class="form-group">
<input type="file" name="photo"/>
</div>
<div class="row form-bottom">
<div class="col">
<input type="submit" value="Add" class="btn" id="btnAdd">
</div>
</div>
<form>
</div>
</div>
</div>
</div>
<header>
...
<div id="main_content">
<div class="container">
<div class="row header-content">
<div class="col title-page">
<h3>Brands</h3>
</div>
<div class="col">
<a href="#AddBrandForm" data-dismiss="modal" data-toggle="modal">Add brand</a>
</div>
</div>
<hr>
<div class="row">
<c:forEach items="${brands}" var="brand">
<div class="col">
<div class="brand-item">
<a href="${pageContext.request.contextPath}/admin/brands/getBrand?id=<c:out value="${brand.getBrandId()}"/>" id="getBrand">
<div class="image">
<img src="${pageContext.request.contextPath}/images?id=<c:out value="${brand.getBrandId()}"/>" />
</div>
<p><c:out value="${brand.getBrandName()}"/></p>
</a>
</div>
</div>
</c:forEach>
</div>
</div>
</div>
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script>
</body>
</html>
我正尝试从模式中编辑品牌，就像我添加品牌一样。我对Spring和Hibernate完全陌生，不知道我是否做对了。通过单击品牌的链接（应打开模式），我会收到此错误：
HTTP Status 500 - Internal Server Error
type Exception report
messageInternal Server Error
descriptionThe server encountered an internal error that prevented it from fulfilling this request.
exception
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalStateException: Optional int parameter 'brandId' is present but cannot be translated into a null value due to being declared as a primitive type. Consider declaring it as object wrapper for the corresponding primitive type.
root cause
java.lang.IllegalStateException: Optional int parameter 'brandId' is present but cannot be translated into a null value due to being declared as a primitive type. Consider declaring it as object wrapper for the corresponding primitive type.
note The full stack traces of the exception and its root causes are available in the GlassFish Server Open Source Edition 4.1.1 logs.
GlassFish Server Open Source Edition 4.1.1
请，如果有人可以帮助我如何获取品牌价值并能够通过模式来对其进行编辑，我将非常感谢您的帮助。预先感谢。
答案 0 :(得分：0)
在您的控制器类中，“ brandId”正在接收空值，而您已将其定义为“ int”类型，该类型不能为空（正如您的错误声明中所述）。 从“ int”更改为“ Integer”。
此外，不确定在请求中从何处获得此参数。我了解您也需要定义路径参数。 （这只是一个观察结果）