web.xml
<servlet>
<servlet-name>springDispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:com/java/bean/SpringMVC.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>springDispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
SpringMVC.xml
<context:component-scan base-package="com.java"></context:component-scan>
<context:property-placeholder location="classpath:druid.properties" />
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
<property name="url" value="https://bbs.csdn.net/topics/${prop.url}"></property>
<property name="username" value="https://bbs.csdn.net/topics/${prop.username}"></property>
<property name="password" value="https://bbs.csdn.net/topics/${prop.password}"></property>
<property name="driverClassName" value="https://bbs.csdn.net/topics/${prop.driverClassName}"></property>
<property name="initialSize" value="https://bbs.csdn.net/topics/${prop.initialSize}"></property>
<property name="maxActive" value="https://bbs.csdn.net/topics/${prop.maxActive}"></property>
</bean>
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource"></property>
</bean>
DAO層
@Repository
public class BookDAOImpl implements BookDAO {
@Autowired
private JdbcTemplate jdbcTemplate;
@Override
增刪改查的方法
}
service層
@Service
public class BookServiceImpl implements BookService {
@Autowired
private BookDAO bookDAO;
@Override
增刪改查的方法
}
JDBC+BookDAOImpl+BookServiceImpl的Test正常，增刪改查都能使用
但是Controller時出錯了，@Autowired無法自動注入
Controller
@Controller
public class bookController {
@Autowired
private BookDAO bookDAO;
@RequestMapping(value="https://bbs.csdn.net/page/book/list_book")
public String listBook(Model model){
List<Book> booklist = bookDAO.query();
model.addAttribute("list",booklist );
return "../manage/book_manage.jsp";
}
}
index頁
<a href="https://bbs.csdn.net/topics/list_book">book管理</a>
book_manage頁
<h1>串列</h1>
<table border="1" cellspacing="0" cellpadding="5">
<tr>
<th>id</th>
<th>name</th>
</tr>
<c:forEach items="${list}" var="book">
<tr>
<td>${list.id}</td>
<td>${list.name}</td>
</tr>
</c:forEach>
</table>
點擊book管理后報錯，錯誤資訊：
org.apache.jasper.JasperException: An exception occurred processing JSP page /page/manage/book_manage.jsp at line 32
29:
30: <c:forEach items="${list}" var="book">
31: <tr>
32: <td>${list.id}</td>
33: <td>${list.name}</td>
嘗試了bookController類里面去除遍歷的功能，是可以正常跳轉的
嘗試了輸出booklist，報錯java.lang.NullPointerException: Cannot invoke "com.book.DAO.BookDAO.query()" because "this.bookDAO" is null
轉載請註明出處，本文鏈接：https://www.uj5u.com/houduan/270092.html
標籤：Web 開發
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