我正在尝试使用Java,Spring,Hibernate和MySQL制作简单的CRUD Web应用程序.我遇到的问题是我无法显示表单以向数据库添加新项目(比萨饼).

这是我的控制器:

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.ui.ModelMap;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.ModelAttribute;
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.support.SessionStatus;

@Controller
public class PizzaController {

  @Autowired private PizzaDao pizzaDao;

  @RequestMapping(method=RequestMethod.GET, value="/")
  public String indexPage(Model model) {
    List pizzas = pizzaDao.getAll();
    model.addAttribute("pizzas", pizzas);
    return "index";
  }
  @RequestMapping(method=RequestMethod.GET, value="Pizza/pizzalist")
  public String pizzalist(Model model) {
    List pizzas = pizzaDao.getAll();
    model.addAttribute("pizzas", pizzas);
    return "pizzalist/pizzalist";
  }
  @RequestMapping(method=RequestMethod.POST, value="Pizza/pizzalist/add")
  public String add(@ModelAttribute("mypizza") Pizza pizza) { //, BindingResult result,         SessionStatus status, ModelMap mmap) {
    //mmap.addAttribute("pizza",pizza);
    pizzaDao.add(pizza);
    //status.setComplete();
    return "pizzalist/pizzalist";
  }
  @RequestMapping(method=RequestMethod.GET, value="Pizza/pizzalist/delete")
  public String delete(@RequestParam("id")long id, Model model) {
    pizzaDao.delete(id);
    List pizzas = pizzaDao.getAll();
    model.addAttribute("pizzas", pizzas);
    return "pizzalist/pizzalist";
  }
  @RequestMapping(method=RequestMethod.POST, value="Pizza/edit")
  public String edit(Model model) {
    List pizzas = pizzaDao.getAll();
    model.addAttribute("pizzas", pizzas);
    return "pizzalist/pizzalist";
  }
}

并查看:

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ include file="/WEB-INF/jsp/includes.jsp"%>







    
List of All Pizzas
    
            

        

                
${p.name}
${p.price}
Delete
            
        
    
    

    
Add new pizza
    
    

        

            
Name
            

        
        

            
Price
            

        
        

            

                
            
        
    
    
    

    Go back to home page

当我只留下显示链接"删除"的可用比萨饼的表格时,一切都显示确定,删除也可以正常工作.

我觉得表单和控制器@ModelAttribute有问题,但我找不到什么是错误的,我在控制器中添加相同的属性,如表单 - "mypizza",这应该有用(至少从我能找到的内容)在谷歌上).

有人可以启发什么阻止此应用程序工作以及如何解决问题？如果需要其他配置文件,我可以提供它们.

UPD:

java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'mypizza' available as request attribute
org.springframework.web.servlet.support.BindStatus.(BindStatus.java:141)
org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.getBindStatus(AbstractDataBoundFormElementTag.java:179)
org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.getPropertyPath(AbstractDataBoundFormElementTag.java:199)
org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.getName(AbstractDataBoundFormElementTag.java:165)
org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.autogenerateId(AbstractDataBoundFormElementTag.java:152)
org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.resolveId(AbstractDataBoundFormElementTag.java:143)
org.springframework.web.servlet.tags.form.AbstractDataBoundFormElementTag.writeDefaultAttributes(AbstractDataBoundFormElementTag.java:127)
org.springframework.web.servlet.tags.form.AbstractHtmlElementTag.writeDefaultAttributes(AbstractHtmlElementTag.java:421)
org.springframework.web.servlet.tags.form.InputTag.writeTagContent(InputTag.java:142)
org.springframework.web.servlet.tags.form.AbstractFormTag.doStartTagInternal(AbstractFormTag.java:103)
org.springframework.web.servlet.tags.RequestContextAwareTag.doStartTag(RequestContextAwareTag.java:80)
org.apache.jsp.WEB_002dINF.jsp.pizzalist.pizzalist_jsp._jspx_meth_form_005finput_005f0(pizzalist_jsp.java:243)
org.apache.jsp.WEB_002dINF.jsp.pizzalist.pizzalist_jsp._jspx_meth_form_005fform_005f0(pizzalist_jsp.java:194)
org.apache.jsp.WEB_002dINF.jsp.pizzalist.pizzalist_jsp._jspService(pizzalist_jsp.java:103)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:238)
org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:263)
org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1208)
org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:992)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:939)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:856)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:936)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:827)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:812)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)

Shay Elkayam.. 8

在这个方法上:

@RequestMapping(method=RequestMethod.GET, value="/")
  public String indexPage(Model model) {
    List pizzas = pizzaDao.getAll();
    model.addAttribute("pizzas", pizzas);
    return "index";
  }

你应该添加以下行:

model.addAttribute("mypizza", new Pizza());

在form:form需要对应于您所定义的的ModelAttribute一个"空"的模式.