java - 在spring mvc和hibernate中将数据从控制器发送到视图的问题
问题描述
我正在尝试学习spring mvc和hibernate，所以我正在做一个关于体育奥运会的CRUD。我的数据库中有两张表，一张名为 Player，另一张名为 Sport。
工具：Netbeans 8.0.2、GlassFish Server 4.1、Java EE 7 web、Spring web MVC 4.0.1、Hibernate 4.3.1
问题：在索引页面中，我需要显示注册球员的数量和注册运动的数量。我使用选择计数来执行此操作，并在我的控制器中尝试使用 get 方法将数据发送到索引，但 index.htm 中没有显示任何数据，似乎不服从控制器。但是可以在浏览器中看到索引页面。
调度程序-servlet.xml
<?xml version='1.0' encoding='UTF-8' ?>
<!-- was: <?xml version="1.0" encoding="UTF-8"?> -->
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">
<bean class="org.springframework.web.servlet.mvc.support.ControllerClassNameHandlerMapping"/>
<!--
Most controllers will use the ControllerClassNameHandlerMapping above, but
for the index controller we are using ParameterizableViewController, so we must
define an explicit mapping for it.
-->
<bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="mappings">
<props>
<prop key="index.htm">indexController</prop>
<prop key="rdeporte.htm">homeController</prop>
<prop key="rjugador.htm">homeController</prop>
<prop key="ujugador.htm">homeController</prop>
<prop key="udeporte.htm">homeController</prop>
<prop key="borrardeporte.htm">homeController</prop>
</props>
</property>
</bean>
<bean id="viewResolver"
class="org.springframework.web.servlet.view.InternalResourceViewResolver"
p:prefix="/WEB-INF/jsp/"
p:suffix=".jsp" />
<!--
The index controller.
-->
<bean name="homeController" class="Controlador.HomeController"></bean>
<bean name="indexController" class="org.springframework.web.servlet.mvc.ParameterizableViewController" p:viewName="index" />
</beans>
索引.jsp
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML>
<html lang="es">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css">
<title>Welcome to Insert with Spring Web MVC project</title>
</head>
<body>
<!-- <div class="container">-->
<div class="row" style="background-color: rgba(0,0,255,.1)">
<div class="col-lg-2">
<div class="container">
<div class="row">
<div class="h-25 d-inline-block" style="text-align:center;font-size:24px;width:100%;height: 50%;background-color: rgba(0,0,255,.1)">OPTIONS</div>
</div>
<div class="row" style="width:100%;padding-top:15%;">
</div>
<div class="row">
<a href="rjugador.htm"><img style="width:100%;height:auto;" src="<c:url value="/resources/img/btnrp.png"/>" alt="Registration of participants"></a>
</div>
<div class="row">
<a href="rdeporte.htm"><img style="width:100%;height:auto;" src="<c:url value="/resources/img/btnrd.png"/>" alt="register new disciplines"></a>
</div>
</div>
</div>
<div class="col-lg-8">
<div class="card border-danger" style="width:100%;height:auto;">
<img class="card-img-top" style="width:100%;height:auto;" src="<c:url value="/resources/img/resSports.png"/>" alt="Card image cap">
<div class="card-header bg-danger">
<h4 style="font-size:auto;">Raccoon city Sports Olimpics</h4>
</div>
</div>
</div>
<div class="col-lg-2">
</div>
</div>
<!-- </div>-->
<div class="container-fluid" style="text-align:center;">
<h2>ESTADISTICS</h2>
</div>
<div class="row">
<div class="navItem" style="font-size:auto; text-align:center;">
<div class="card" style="width: 100%; float: ">
<img class="card-img-top" src="<c:url value="/resources/img/cabecerap.png"/>" alt="Card image cap">
<div class="card-body">
<div class="card-text">
<p>Players:</p><c:out value="${ numPlayers }"/>
</div>
</div>
</div>
</div>
<div class="navItem" style="font-size:auto; text-align:center;">
<div class="card" style="width: 100%; float: ">
<img class="card-img-top" src="<c:url value="/resources/img/cabecerad.png"/>" alt="Card image cap">
<div class="card-body">
<div class="card-text">
<p>Sports:</p>
</div>
</div>
</div>
</div>
</div>
<div class="container-fluid">
<p>something</p>
</div>
</body>
</html>
Web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.1" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd">
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/applicationContext.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<servlet>
<servlet-name>dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>2</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcher</servlet-name>
<url-pattern>*.htm</url-pattern>
</servlet-mapping>
<session-config>
<session-timeout>
30
</session-timeout>
</session-config>
<welcome-file-list>
<welcome-file>redirect.jsp</welcome-file>
</welcome-file-list>
</web-app>
package Controlador;
@Controller
public class HomeController {
/* this controller does not want to work */
@RequestMapping(value="index.htm", method = RequestMethod.GET)
public ModelAndView index(){
ModelAndView mav= new ModelAndView();
Estadistics est=new Estadistics();
mav.addObject("numPlayers",est.getNumPlayers());
mav.setViewName("index");
return mav;
}
@RequestMapping(value="rjugador.htm", method = RequestMethod.GET)
public ModelAndView rjugador(){
/***Other Controlers***/
.......................
}
package Controlador;
public class Estadistics {
public int getNumPlayers (){
int c=queries("select count(j) from Player as j");
return c;
}
public int queries(String hql) {
int num=0;
try
{
Configuration configuration = new Configuration().configure();
StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder().
applySettings(configuration.getProperties());
SessionFactory session = configuration.buildSessionFactory(builder.build());
Session ses;
ses=session.openSession();
Query q=ses.createQuery(hql);
num = q.getFirstResult();
ses.close();
}catch(HibernateException ex){
}
return num;
}
}
查询有效 https://drive.google.com/open?id=13khiwcVJ2sS0qn49LAG4m3s00nlzVIBX
解决方案
您应该开始检查您的映射，看起来您的调度程序正在等待 .jsp，而您还没有。
你能分享你完整的JSP文件吗？
最好检查一下您的查询是否真的返回了一些东西。您可以添加一些日志来打印号码，然后再将其发送到您的视图。
看看这个例子：SimplerUrlHandlerMapping
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