JSP 欢迎文件问题

Question

我在 web.xml 中提供了欢迎文件，但是在运行我的 spring 应用程序时，它在 http://localhost:8080/web_customer_tracker/ 上显示 404 错误

我使用 IntelliJ IDEA，GlassFish 5.0.0，index.jsp 文件在 web 文件夹下，web.xml 在 web/WEB-INF 文件夹下。

这里是 web.xml

 <?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xmlns="http://xmlns.jcp.org/xml/ns/javaee"
             xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
             id="WebApp_ID" version="3.1">

  <display-name>spring-mvc-crud-demo</display-name>

  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>index.html</welcome-file>
  </welcome-file-list>

  <servlet>
    <servlet-name>dispatcher</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>/WEB-INF/spring-mvc-crud-demo-servlet.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>

  <servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>
</web-app>

spring-mvc-crud-demo-servlet.xml

  <?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:context="http://www.springframework.org/schema/context"
        xmlns:tx="http://www.springframework.org/schema/tx"
        xmlns:mvc="http://www.springframework.org/schema/mvc"
        xsi:schemaLocation="
            http://www.springframework.org/schema/beans
            http://www.springframework.org/schema/beans/spring-beans.xsd
            http://www.springframework.org/schema/context
            http://www.springframework.org/schema/context/spring-context.xsd
            http://www.springframework.org/schema/mvc
            http://www.springframework.org/schema/mvc/spring-mvc.xsd
            http://www.springframework.org/schema/tx 
            http://www.springframework.org/schema/tx/spring-tx.xsd">

        <!-- Add support for component scanning -->
        <context:component-scan base-package="com.pindc.springdemo" />

        <!-- Add support for conversion, formatting and validation support -->
        <mvc:annotation-driven/>

        <!-- Define Spring MVC view resolver -->
        <bean
            class="org.springframework.web.servlet.view.InternalResourceViewResolver">
            <property name="prefix" value="/WEB-INF/view/" />
            <property name="suffix" value=".jsp" />
        </bean>

        <!-- Step 1: Define Database DataSource / connection pool -->
        <bean id="myDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
              destroy-method="close">
            <property name="driverClass" value="com.mysql.cj.jdbc.Driver" />
            <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/web_customer_tracker?useSSL=false&amp;serverTimezone=UTC" />
            <property name="user" value="springstudent" />
            <property name="password" value="springstudent" /> 

            <!-- these are connection pool properties for C3P0 -->
            <property name="minPoolSize" value="5" />
            <property name="maxPoolSize" value="20" />
            <property name="maxIdleTime" value="30000" />
        </bean>  

        <!-- Step 2: Setup Hibernate session factory -->
        <bean id="sessionFactory"
            class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
            <property name="dataSource" ref="myDataSource" />
            <property name="packagesToScan" value="com.pindc.springdemo.entity" />
            <property name="hibernateProperties">
               <props>
                  <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
                  <prop key="hibernate.show_sql">true</prop>
               </props>
            </property>
       </bean>    

        <!-- Step 3: Setup Hibernate transaction manager -->
        <bean id="myTransactionManager"
                class="org.springframework.orm.hibernate5.HibernateTransactionManager">
            <property name="sessionFactory" ref="sessionFactory"/>
        </bean>

        <!-- Step 4: Enable configuration of transactional behavior based on annotations -->
        <tx:annotation-driven transaction-manager="myTransactionManager" />

        <!-- entry to use resources in spring MVC -->
        <mvc:resources mapping="/resources/**" location="/resources/"/>


    </beans>

index.jsp

<%response.sendRedirect("customer/list"); %>

客户控制器

package com.pindc.springdemo.controller;

import com.pindc.springdemo.dao.CustomerDAO;
import com.pindc.springdemo.entity.Customer;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;

import java.util.List;

@Controller
@RequestMapping("/customer")
public class CustomerController {

    //Inject our DAO
    @Autowired
    private CustomerDAO customerDAO ;


    @RequestMapping("/list")
    public String listCustomer(Model model){

        //Get Customer from our DAO

        List<Customer> customers = customerDAO.getCostumers();

        //Add costumers to the model
        model.addAttribute("customers",customers);

        return "list-customer";
    }
}

Answer 1

在春季，每个请求都将由 DispatcherServlet 处理。仅当使用 @RequestMapping 注释进行映射时，它才会解析 URL。在您的 web.xml 中，您已经指定了索引页面列表，但 servlet 无法识别它。

为了完成这项工作，创建新的控制器类，@RequestMapping 值为 ("/") 并返回索引页的名称。

@Controller
@RequestMapping(value="/")
public class IndexController {

    @RequestMapping(value="")
    public String indexPage(Model model){

        return "index";
    }
}

将您的 index.jsp 文件放在路径中 - /WEB-INF/view/，无需在 web.xml 中指定 welcome-file-list。