问题遇到的现象和发生背景
SSM整合，404错误源服务器未能找到目标资源的表示或者是不愿公开一个已经存在的资源表示。
问题相关代码，请勿粘贴截图
index.jsp
```html
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<!DOCTYPE HTML>
<html>
<head>
<title>首页</title>
<style type="text/css">
a {
text-decoration: none;
color: black;
font-size: 18px;
}
h3 {
width: 180px;
height: 38px;
margin: 100px auto;
text-align: center;
line-height: 38px;
background: deepskyblue;
border-radius: 4px;
}
</style>
</head>
<body>
<h3>
<a href="${pageContext.request.contextPath}/book/allBook">点击进入列表页</a>
</h3>
</body>
</html>
BookController.java
```java
package com.luo.controller;
import com.luo.pojo.Books;
import com.luo.service.BookService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import java.util.List;
@Controller
@RequestMapping("/book")
public class BookController {
@Autowired
@Qualifier("BookServiceImpl")
private BookService bookService;
@RequestMapping("/allBook")
public String list(Model model) {
List<Books> list = bookService.queryAllBook();
model.addAttribute("list", list);
return "allBook";
}
@RequestMapping("/toAddBook")
public String toAddPaper() {
return "addBook";
}
@RequestMapping("/addBook")
public String addPaper(Books books) {
System.out.println(books);
bookService.addBook(books);
return "redirect:/book/allBook";
}
@RequestMapping("/toUpdateBook")
public String toUpdateBook(Model model, int id) {
Books books = bookService.queryBookById(id);
System.out.println(books);
model.addAttribute("book",books );
return "updateBook";
}
@RequestMapping("/updateBook")
public String updateBook(Model model, Books book) {
System.out.println(book);
bookService.updateBook(book);
Books books = bookService.queryBookById(book.getBookID());
model.addAttribute("books", books);
return "redirect:/book/allBook";
}
@RequestMapping("/del/{bookId}")
public String deleteBook(@PathVariable("bookId") int id) {
bookService.deleteBookById(id);
return "redirect:/book/allBook";
}
}
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app 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_4_0.xsd"
version="4.0"
metadata-complete="true">
<!--DispatcherServlet-->
<servlet>
<servlet-name>DispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<!--一定要注意:我们这里加载的是总的配置文件，之前被这里坑了！-->
<param-value>classpath:applicationContext.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>DispatcherServlet</servlet-name>
<url-pattern>/DispatcherServlet</url-pattern>
</servlet-mapping>
<!--encodingFilter-->
<filter>
<filter-name>encodingFilter</filter-name>
<filter-class>
org.springframework.web.filter.CharacterEncodingFilter
</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!--Session过期时间-->
<session-config>
<session-timeout>15</session-timeout>
</session-config>
</web-app>
spring-mvc.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: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
https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!-- 配置SpringMVC -->
<!-- 1.开启SpringMVC注解驱动 -->
<mvc:annotation-driven />
<!-- 2.静态资源默认servlet配置-->
<mvc:default-servlet-handler/>
<!-- 3.配置jsp 显示ViewResolver视图解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
<property name="prefix" value="/WEB-INF/jsp/" />
<property name="suffix" value=".jsp" />
</bean>
<!-- 4.扫描web相关的bean -->
<context:component-scan base-package="com.luo.controller" />
</beans>
运行结果及报错内容
