import 简化Spring 配置文件

刺骨的言语ヽ痛彻心扉 2023-10-16 22:11 21阅读 0赞

对于编写SSH程序的程序员来说，Spring的配置文件（applicationContext.xml）是一个非常让人头疼的一个问题，自己的一个不小心会导致，项目的异常或者更为严重的是项目无法启动。如何解决applicationContext.xml 配置文件臃肿的问题，是本篇文章讨论的重点。对于一个拥有丰富编码经验的工程师，一定会想到使用"import"策略，优化applicationContext.xml配置文件。

大家接下来，看到的这段代码是一个非常web简单项目的配置文件.

<?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:aop="http://www.springframework.org/schema/aop"
    	xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context"
    	xsi:schemaLocation="
         http://www.springframework.org/schema/beans 
         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
         http://www.springframework.org/schema/tx 
         http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
         http://www.springframework.org/schema/aop 
         http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context-3.0.xsd">
    
    	
    	<bean id="myDataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    		<property name="driverClassName" value="com.mysql.jdbc.Driver" />
    		<property name="url" value="jdbc:mysql://localhost:3306/test" />
    		<property name="username" value="root" />
    		<property name="password" value="123456" />
    	</bean>
    	
    	<bean id="mySessionFactory"
    		class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
    		<property name="dataSource" ref="myDataSource" />
    		<property name="mappingResources">
    			<list>
    				<value>User.hbm.xml</value>
    			</list>
    		</property>
    		<property name="hibernateProperties">
    			<props>
    				<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
    				<prop key="hibernate.show_sql">true</prop>
    				<prop key="hibernate.format_sql">true</prop>
    			</props>
    		</property>
    	</bean>
    	
    	<bean id="UserDaoImpl" class="ssh.Dao.UserDaoImpl">
    		<property name="factory" ref="mySessionFactory"></property>
    	</bean>
    
    	<bean id="UserServiceImpl" class="ssh.Service.UserServiceImpl">
    		<property name="personDao" ref="UserDaoImpl"></property>
    	</bean>
    
    	<bean id="UserAction" class="ssh.action.UserAction" scope="prototype">
    		<property name="userServiceimpl" ref="UserServiceImpl"></property>
    	</bean>
    
    	
    	
    </beans>

大家看了这段代码是不是感觉，这也没有什么复杂的，但是我们的从spring 配置文件完成了那些功能来说起：数据源配置、Dao层实现、Service层实现、Action控制层和数据库操作sessionFactory，大家有没有感觉是不是这个applicationContext.xml需要完成的事情是不是太多了。我们必须简化好一下。

大家请看第二段代码：是进过简单的优化 代码，在applicationContext.xml 同一级目录，我们建立了一个SpringBean.xml文件（名称可以自己任意定义）。

springBean.xml

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" 
    "http://www.springframework.org/dtd/spring-beans-2.0.dtd">
    
    <beans>
    	<bean id="UserDaoImpl" class="ssh.Dao.UserDaoImpl">
    		<property name="factory" ref="mySessionFactory"></property>
    	</bean>
    
    	<bean id="UserServiceImpl" class="ssh.Service.UserServiceImpl">
    		<property name="personDao" ref="UserDaoImpl"></property>
    	</bean>
    
    	<bean id="UserAction" class="ssh.action.UserAction" scope="prototype">
    		<property name="userServiceimpl" ref="UserServiceImpl"></property>
    	</bean>
    </beans>

applicationContext 通过import策略，引用其他的配置文件信息。

<?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:aop="http://www.springframework.org/schema/aop"
    	xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context"
    	xsi:schemaLocation="
         http://www.springframework.org/schema/beans 
         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
         http://www.springframework.org/schema/tx 
         http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
         http://www.springframework.org/schema/aop 
         http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context-3.0.xsd">
    
    	
    	<bean id="myDataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    		<property name="driverClassName" value="com.mysql.jdbc.Driver" />
    		<property name="url" value="jdbc:mysql://localhost:3306/test" />
    		<property name="username" value="root" />
    		<property name="password" value="123456" />
    	</bean>
    	
    	<bean id="mySessionFactory"
    		class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
    		<property name="dataSource" ref="myDataSource" />
    		<property name="mappingResources">
    			<list>
    				<value>User.hbm.xml</value>
    			</list>
    		</property>
    		<property name="hibernateProperties">
    			<props>
    				<prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
    				<prop key="hibernate.show_sql">true</prop>
    				<prop key="hibernate.format_sql">true</prop>
    			</props>
    		</property>
    	</bean>
    
    	
    	<import resource="springBean.xml"></import>
    	
    </beans>