spring通过.PropertyPlaceholderConfigurer读取配置文件

 <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
  <property name="systemPropertiesModeName" value="SYSTEM_PROPERTIES_MODE_OVERRIDE" />
  <property name="ignoreResourceNotFound" value="true" />
  <property name="locations">
   <list>
    <!-- 标准配置 -->
    <value>classpath*:/application.properties</value>
   </list>
  </property>
 </bean>

 <!-- 数据源配置,使用应用内的DBCP数据库连接池 -->
 <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
  <!-- Connection Info -->
  <property name="driverClassName" value="${jdbc.driver}" />
  <property name="url" value="${jdbc.url}" />
  <property name="username" value="${jdbc.username}" />
  <property name="password" value="${jdbc.password}" />

 

  <!-- Connection Pooling Info -->
  <property name="initialSize" value="5" />
  <property name="maxActive" value="100" />
  <property name="maxIdle" value="30" />
  <property name="maxWait" value="500" />
  <property name="poolPreparedStatements" value="false" />
  <property name="defaultAutoCommit" value="false" />
 </bean>

 

 

<bean id="sessionFactory"
  class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
  <property name="dataSource">
   <ref bean="dataSource" />
  </property>
  <property name="hibernateProperties">
   <props>
    <prop key="hibernate.dialect">
     ${hibernate.dialect}
    </prop>
    <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
          <prop key="hibernate.format_sql">${hibernate.format_sql}</prop>
   </props>
  </property>
  <property name="mappingResources">
   <list>
    <value>org/cfw/hibernate/Test.hbm.xml</value>
    <value>org/cfw/hibernate/Dataofchina.hbm.xml</value>
  </list>
  </property>
 </bean> 

 

 

 

application.properties 内容如下

 

#mysql database setting
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost/ss?useUnicode=true&amp;characterEncoding=utf-8
jdbc.username=root
jdbc.password=1234
hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect

#hibernate settings
hibernate.show_sql=false
hibernate.format_sql=false
hibernate.ehcache_config_file=/ehcache/ehcache-hibernate-local.xml

 

 

谁能帮我解释一下systemPropertiesModeName 和 ignoreResourceNotFound 这俩参数干嘛用的，第二个源程序里都没有这个变量...