2.在Spring中,使用PropertyPlaceholderConfigurer可以在XML配置文件中加入外部屬性文件,當然也可以指定外部文件的編碼,如:
<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location">
<value>conf/sqlmap/jdbc.properties</value>
</property>
<property name="fileEncoding">
<value>UTF-8</value>
</property>
</bean>
當然也可以引入多個屬性文件,如:
<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>/WEB-INF/mail.properties</value>
<value>classpath: conf/sqlmap/jdbc.properties</value>//注意這兩種value值的寫法
</list>
</property>
</bean>
基本的使用方法是:
Xml代碼
<bean id="propertyConfigurerForAnalysis" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location">
<value>classpath:/spring/include/dbQuery.properties</value>
</property>
<property name="fileEncoding">
<value>UTF-8</value>
</property>
</bean>
其中classpath是引用src目錄下的文件寫法。
當存在多個Properties文件時,配置就需使用locations了:
Xml代碼
<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath:/spring/include/jdbc-parms.properties</value>
<value>classpath:/spring/include/base-config.properties</value>
<value>classpath*:config/jdbc.properties</value>
</list>
</property>
</bean>
接下來我們要使用多個PropertyPlaceholderConfigurer來分散配置,達到整合多工程下的多個分散的Properties文件,其配置如下
Xml代碼
<bean id="propertyConfigurerForProject1" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="order" value="1" />
<property name="ignoreUnresolvablePlaceholders" value="true" />
<property name="location">
<value>classpath:/spring/include/dbQuery.properties</value>
</property>
</bean>
Xml代碼
<bean id="propertyConfigurerForProject2" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="order" value="2" />
<property name="ignoreUnresolvablePlaceholders" value="true" />
<property name="locations">
<list>
<value>classpath:/spring/include/jdbc-parms.properties</value>
<value>classpath:/spring/include/base-config.properties</value>
</list>
</property>
</bean> 其中order屬性代表其加載順序,而ignoreUnresolvablePlaceholders爲是否忽略不可解析的Placeholder,如配置了多個PropertyPlaceholderConfigurer,則需設置爲true
3.譬如,jdbc.properties的內容爲:
jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost/mysqldb?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=round;
jdbc.username=root
jdbc.password=123456
4.那麼在spring配置文件中,我們就可以這樣寫:
<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<list>
<value>classpath: conf/sqlmap/jdbc.properties </value>
</list>
</property>
</bean>
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="${jdbc.driverClassName}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
</bean>
5.這樣,一個簡單的數據源就設置完畢了。可以看出:PropertyPlaceholderConfigurer起的作用就是將佔位符指向的數據庫配置信息放在bean中定義的工具。
- <!-- dataSource -->
- <bean id="dataSource"
- class="org.springframework.jdbc.datasource.DriverManagerDataSource">
- <property name="driverClassName"
- value="${jdbc.driverClassName}" />
- <property name="url" value="${jdbc.url}" />
- <property name="username" value="${jdbc.username}" />
- <property name="password" value="${jdbc.password}" />
- </bean>
- <!-- sessionFactory -->
- <bean id="sessionFactory"
- class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
- <property name="dataSource" ref="dataSource" />
- <property name="mappingResources">
- <list>
- <value>cn/xg/hibernate/spring/User.hbm.xml</value><!--這裏的映射路徑問題,這種方法只能一個一個加-->
- <value>cn/xg/hibernate/spring/Group.hbm.xml</value>
- </list>
- <!-- 加載一個路徑下的*.hbm.xml文件方法:
- <property name="mappingDirectoryLocations">
- <list>
- <value>classpath:/cn/xg/spring/model</value>
- </list>
- </property>
- -->
- </property>
- <property name="hibernateProperties">
- <props>
- <prop key="hibernate.dialect">
- ${hibernate.dialect}
- </prop>
- <prop key="hibernate.show_sql">true</prop>
- </props>
- </property>
- </bean>
- <!-- DAO實現類extends HibernateDaoSupport,注入sessionFactory -->
- <bean id="userMgrImpl" class="cn.xg.hibernate.spring.UserMgrImpl">
- <property name="sessionFactory" ref="sessionFactory" />
- </bean>
- <bean id="groupMgrImpl"
- class="cn.xg.hibernate.spring.GroupMgrImpl">
- <property name="sessionFactory" ref="sessionFactory" />
- <property name="userImpl" ref="userMgrImpl"/>
- <property name="transactionTemplate" ref="transactionTemplate"/>
- </bean>
- <!-- 事務管理 -->
- <bean id="transactionManager"
- class="org.springframework.orm.hibernate3.HibernateTransactionManager">
- <property name="sessionFactory" ref="sessionFactory" />
- </bean>
- <!-- 編程式事務的寫法 :向Dao實現類中注入transactionTemplate,調動其execute()方法,接口回調new TransactionCallback()-->
- <bean id="transactionTemplate" class="org.springframework.transaction.support.TransactionTemplate">
- <property name="transactionManager" ref="transactionManager"/>
- </bean>
- <!-- 聲時式事務第一種寫法 -->
- <!--
- <bean id="groupMgr"
- class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
- <property name="transactionManager" ref="transactionManager" />
- <property name="target" ref="groupMgrImpl" />
- <property name="transactionAttributes">
- <props>
- <prop key="add*">PROPAGATION_REQUIRED</prop>
- <prop key="get*">PROPAGATION_REQUIRED</prop>
- <prop key="*">readOnly</prop>
- </props>
- </property>
- </bean>
- -->
- <!-- 聲時式事務第二種寫法 -->
- <!-- 事務的傳播特性
- <tx:advice id="txAdvice">
- <tx:attributes>
- <tx:method name="add*" propagation="REQUIRED" />
- <tx:method name="get*" propagation="REQUIRED" />
- <tx:method name="*" read-only="true" />
- </tx:attributes>
- </tx:advice>
- <aop:config>
- <aop:advisor pointcut="execution(* cn.xg.hibernate.spring.*.*(..))"
- advice-ref="txAdvice" />
- </aop:config>
- -->
- </beans>
- jdbc.properties
- jdbc.driverClassName=com.mysql.jdbc.Driver
- jdbc.url=jdbc:mysql://localhost:3306/數據庫名
- jdbc.username=數據庫用戶名
- jdbc.password=數據庫密碼
- hibernate.dialect=org.hibernate.dialect.MySQLDialect(方言.這裏是MySql)