Spring整合SpringMVC

旧城等待， 2024-04-19 11:22 66阅读 0赞

## Spring整合SpringMVC ##

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。

**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。  
**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：**

Controller在SpringMVC中扫描，视图解析器等在SpringMVC容器中配置
    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

<context:component-scan base-package="com.i.controller"></context:component-scan>
    
    	
    	<context:component-scan base-package="com.i.controller" use-default-filters="false">
        		
        		<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
        </context:component-scan>

**use-default-filters 属性**  
  属性的默认值为 **true**，即使用默认的 Filter 进行包扫描，**而默认的 Filter 对标有 @Service,@Controller和@Repository 的注解的类进行扫描，**  
  我们希望 SpringMVC 只来控制网站的跳转逻辑，所以我们只希望 SpringMVC 的配置扫描 @Controllerce 注解标注的类，不希望它扫描其余注解标注的类，所以设置了 use-default-filters 为 false，并使用**context:include-filter**子标签设置其只扫描带有 **@Controller** 注解标注的类。

而 Spring 就不同了，我们希望 Spring 只不扫描带有 @Controller 注解标注的类，而扫描其他注解标注的类，而这时建立在使用默认的 Filter 进行扫描的基础上，设置了 **context:exclude-filter** 标签，不扫描 @Controller 注解标注的类，所以不应该设置 use-default-filters 为 false，所以这就解释了为什么一开始启动 Tomcat 时报了一个找不到 Service 的错误

在使用 use-default-filters 属性时要分清楚需要扫描哪些包，是不是需要使用默认的 Filter 进行扫描。楼主稍微总结一下，即 use-default-filters=“false” 需要和 context:include-filter 一起使用，而不能和 context:exclude-filter 属性一起使用

jar包

com.springsource.org.apache.commons.logging-1.1.1.jar
    	commons-fileupload-1.3.1.jar
    	commons-io-2.4.jar
    	spring-aop-4.3.10.RELEASE.jar
    	spring-aspects-4.3.10.RELEASE.jar
    	spring-beans-4.3.10.RELEASE.jar
    	spring-context-4.3.10.RELEASE.jar
    	spring-core-4.3.10.RELEASE.jar
    	spring-expression-4.3.10.RELEASE.jar
    	spring-jdbc-4.3.10.RELEASE.jar
    	spring-orm-4.3.10.RELEASE.jar
    	spring-tx-4.3.10.RELEASE.jar
    	spring-web-4.3.10.RELEASE.jar
    	spring-webmvc-4.3.10.RELEASE.jar
    	jackson-annotations-2.5.0.jar
    	jackson-core-2.5.2.jar
    	jackson-databind-2.5.2.jar
    	jstl-1.2.jar
    	mysql-connector-java-5.1.47.jar

**Spring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-4.3.xsd">
    
    	
    		<context:component-scan base-package="com.i.service.impl,com.i.dao.impl" use-default-filters="true">
    			
    			<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    	    </context:component-scan>
        
        
    		<bean class="org.springframework.jdbc.datasource.DriverManagerDataSource" id="dataSource">
    			
    			<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
    			<property name="url" value="jdbc:mysql://127.0.0.1:3306/demo?characterEncoding=utf-8"/>
    			<property name="username" value="root"/>
    			<property name="password" value="1234"/>
    		</bean>
    	
    		<bean class="org.springframework.jdbc.core.JdbcTemplate">
    			<constructor-arg name="dataSource" ref="dataSource"></constructor-arg>
    		</bean>
    </beans>

**SpringMVC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/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">
     
     	
        
        	<context:component-scan base-package="com.i.controller" use-default-filters="false">
        		
        		<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
        	</context:component-scan>
        
    	   <mvc:annotation-driven ></mvc:annotation-driven>
        	
    	
    	     <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    	       
    	        <property name="suffix" value=".jsp"/>
    	    </bean>
    	    
       	
           <mvc:resources location="/js/" mapping="/js/**"></mvc:resources>
           <mvc:resources location="/css/" mapping="/css/**"></mvc:resources>
           <mvc:resources location="/images/" mapping="/images/**"></mvc:resources>
    	     
    	
    		<bean id="exceptionResolver" class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
    			<property name="exceptionMappings">
    				<props>
    					
    					<prop key="java.lang.NullPointerException">error.jsp</prop>
    				</props>
    			</property>
    		</bean>
    </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" version="3.0">
      <display-name>springmvc-8</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>
      
      
    		<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>spring-mvc</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>
    	  	<load-on-startup>1</load-on-startup>
    	  </servlet>
    	  
    	  <servlet-mapping>
    	  	<servlet-name>spring-mvc</servlet-name>
    	  	<url-pattern>/</url-pattern>
    	  </servlet-mapping>
      
    		  <filter>
    		      <filter-name>character</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>character</filter-name>
    		      <url-pattern>/*</url-pattern>
    		  </filter-mapping>
    </web-app>

**controller代码**

@Controller
    public class UserController { 
    
    	@Autowired
    	private UserService userService;
    	
    	@RequestMapping("query")
    	public String query(Model m){ 
    		List<User> list = userService.query();
    		System.out.println(list);
    		m.addAttribute("list",list);
    		return "user";
    	}
    }

**Service**

public interface UserService { 
    
    	List<User> query();
    }

@Service
    public class UserServiceImpl implements UserService{ 
    	
    	@Autowired
    	private UserDao dao;
    
    	@Override
    	public List<User> query() { 
    		return dao.query();
    	}
    }

**Dao**

public interface UserDao { 
    
    	List<User> query();
    }

@Repository
    public class UserDaoImpl implements UserDao { 
    	
    	@Autowired
    	private JdbcTemplate template;
    
    	@Override
    	public List<User> query() { 
    		String sql = "SELECT * FROM users";
    		return template.query(sql, new BeanPropertyRowMapper<User>(User.class));
    	}
    }

**jsp页面**

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8"%>
    <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>Insert title here</title>
    <script type="text/javascript" src="js/jquery.min.js"></script>
    </head>
    <body>
    	
    	<c:forEach items="${list}" var="i">
    		${ i.userid}--${ i.username}--${ i.userage}<br>
    	</c:forEach>
    </body>
    </html>

![在这里插入图片描述][2019091718490360.png]

[2019091718490360.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/22c7a0f9a38748888dac20e731ec7d39.png