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1.Spring容器和SpringMVC容器的关系

Spring容器是一个父容器，SpringMVC容器是一个子容器，它继承自Spring容器。因此，在SpringMVC容器中，可以访问到Spring容器中定义的Bean，而在Spring容器中，无法访问SpringMVC容器中定义的Bean。在Web开发中，Controller全部在SpringMVC中扫描，除了Controller之外的Bean，全部在Spring容器中扫描（Service、Dao），按这种方式扫描，扫描完完成后，Controller可以访问到Service。


1.为什么不全部都在Spring中扫描
因为处理器映射器只会去SpringMVC中查找到Controller，如果没有，就找不到，不会去Spring中找，这就决定了，Controller必须在SpringMVC中扫描。
2.为什么不全部在SpringMVC中扫描
在SSM整合或者Spring+SpringMVC+JdbcTemplate中，可以全部在SpringMVC中扫描，但是，在SSH整合中，这种方式不允许。


最佳实践：
1.Controller在SpringMVC中扫描，视图解析器等在SpringMVC容器中配置
2.Spring中扫描Service、Dao已经其他组件，事务定义、数据源定义都在Spring容器中配置

2.SpringMVC的配置文件

<?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"
    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">   
     <!-- 在Spring容器中，扫描除了Controller之外的其他组件 -->
    <context:component-scan base-package="com.dpb"
        use-default-filters="true">
        <context:exclude-filter type="annotation"
            expression="org.springframework.stereotype.Controller" />
    </context:component-scan>
</beans>

3.Spring的配置文件

<?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 http://www.springframework.org/schema/mvc/spring-mvc.xsd">  
      <!-- SpringMVC容器只扫描Controller -->
    <context:component-scan base-package="com.dpb"
        use-default-filters="false">
        <context:include-filter type="annotation"
            expression="org.springframework.stereotype.Controller" />
    </context:component-scan>
    <mvc:annotation-driven />
</beans>

4.web.xml文件中

分别加载spring和SpringMVC的配置

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    id="WebApp_ID" version="3.0">
    <display-name>test</display-name>
    <!-- 这里配置Spring配置文件的位置，param-name是固定的，
    param-value是文件位置 这个配置可以省略，如果省略，
    系统默认去/WEB-INF/目录下查找applicationContext.xml作为Spring的配置文件 -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring-servlet.xml</param-value>
        </init-param>
    </servlet>
    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
    <filter>
        <filter-name>encoding</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>
        <init-param>
            <param-name>forceRequestEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
        <init-param>
            <param-name>forceResponseEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

5.案例实现

SpringMVC配置文件

<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"
    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">    
    
    <!-- 在Spring容器中，扫描除了Controller之外的其他组件 -->
    <context:component-scan base-package="com.dpb"
        use-default-filters="true">
        <!-- 不扫描Controller注解 -->
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller" />
    </context:component-scan>
    
    <!-- 配置一个数据源 -->
    <bean class="org.springframework.jdbc.datasource.DriverManagerDataSource" id="ds">
        <property name="url" value="jdbc:oracle:thin:@localhost:1521:orcl"/>
        <property name="driverClassName" value="oracle.jdbc.driver.OracleDriver"/>
        <property name="username" value="pms"/>
        <property name="password" value="pms"/>
    </bean>
    
    <!-- 配置JdbcTemplate实例 -->
    <bean class="org.springframework.jdbc.core.JdbcTemplate" id="jdbcTemplate">
        <!-- 通过构造注入的方式关联数据源 -->
        <constructor-arg name="dataSource" ref="ds"/>
    </bean>
</beans>

Spring配置文件

<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/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
        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-4.3.xsd">
    <!-- 开启注解 -->
    <mvc:annotation-driven></mvc:annotation-driven>
    <!-- 开启扫描 -->
    <context:component-scan base-package="com.dpb.*">
        <!-- 只扫描特定的注解 -->
        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>
</beans>

web.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    id="WebApp_ID" version="3.0">
    <display-name>test</display-name>
    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
        <welcome-file>default.html</welcome-file>
        <welcome-file>default.htm</welcome-file>
        <welcome-file>default.jsp</welcome-file>
    </welcome-file-list>

    <!-- 这里配置Spring配置文件的位置，param-name是固定的，
        param-value是文件位置 这个配置可以省略，如果省略，
        系统默认去/WEB-INF/目录下查找applicationContext.xml作为Spring的配置文件 
    -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <!-- 配置前端控制器 -->
    <!-- contextConfigLocation配置springmvc加载的配置文件（配置处理器映射器、适配器等等） 如果不配置contextConfigLocation， 
        默认加载的是/WEB-INF/servlet名称-serlvet.xml（springmvc-servlet.xml） -->
    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring-mvc.xml</param-value>
        </init-param>
    </servlet>

    <servlet-mapping>
        <servlet-name>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!-- 防止资源文件被spring MVC拦截 -->
    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.jpg</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.js</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.css</url-pattern>
    </servlet-mapping>
</web-app>

Dao代码

/**
 * 
 * @author dpb【波波烤鸭】
 *
 */
public interface IUserDao {

    public List<User> query();
}

/**
 * dao层实现
 * @author dpb【波波烤鸭】
 *
 */
@Repository
public class UserDaoImpl implements IUserDao {
    
    @Resource
    JdbcTemplate jdbcTemplate;

    @Override
    public List<User> query() {
        String sql = "select * from t_sysuser ";
        return jdbcTemplate.query(sql, new BeanPropertyRowMapper<User>(User.class));
    }
}

Service代码

/**
 * 
 * @author dpb【波波烤鸭】
 *
 */
public interface IUserService {

    public List<User> query();
}

/**
 * 
 * @author dpb【波波烤鸭】
 *
 */
@Service
public class UserServiceImpl implements IUserService {
    
    @Resource
    private IUserDao dao;

    @Override
    public List<User> query() {
        // TODO Auto-generated method stub
        return dao.query();
    }
}

controller代码

/**
 * 案例
 * 
 * @author dpb【波波烤鸭】
 *
 */
@Controller
public class UserController {

    @Resource
    private IUserService userService;
    
    @RequestMapping("/query")
    public String query(Model model){
        List<User> list = userService.query();
        model.addAttribute("list", list);
        return "/user.jsp";
    }
    
}

jsp页面代码

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>

    <c:forEach items="${list }" var="user">
        ${user.id }--${user.uname }--${user.nickname }<br>
    </c:forEach>
</body>
</html>

查询结果

案例代码：链接：https://pan.baidu.com/s/1J26hh7FL1s2HuJJnxkUIaw
提取码：l1cs
上一篇:SpringMVC教程4

整合Spring和SpringMVC

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原文地址：https://www.cnblogs.com/dengpengbo/p/10308105.html