Spring實戰(zhàn)之屬性覆蓋占位符配置器用法示例

<?xml version="1.0" encoding="GBK"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns="http://www.springframework.org/schema/beans"
   xsi:schemaLocation="http://www.springframework.org/schema/beans
   http://www.springframework.org/schema/beans/spring-beans-4.0.xsd">
   <!-- PropertyOverrideConfigurer是一個容器后處理器，它會讀取
   屬性文件信息，并用這些信息設(shè)置覆蓋Spring配置文件的數(shù)據(jù) -->
   <bean class=
   "org.springframework.beans.factory.config.PropertyOverrideConfigurer">
      <property name="locations">
        <list>
           <value>dbconn.properties</value>
           <!-- 如果有多個屬性文件,依次在下面列出來 -->
        </list>
      </property>
   </bean>
   <!-- 定義數(shù)據(jù)源Bean，使用C3P0數(shù)據(jù)源實現(xiàn),
      配置該Bean時沒有指定任何信息，但Properties文件里的
      信息將會直接覆蓋該Bean的屬性值 -->
   <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
      destroy-method="close"/>
</beans>

dataSource.driverClass=com.mysql.jdbc.Driver
dataSource.jdbcUrl=jdbc:mysql://localhost:3306/spring
dataSource.user=root
dataSource.password=32147

package lee;
import javax.sql.DataSource;
import java.sql.*;
import org.springframework.context.*;
import org.springframework.context.support.*;
public class BeanTest
{
  public static void main(String[] args)throws Exception
  {
    ApplicationContext ctx = new
      ClassPathXmlApplicationContext("beans.xml");
    DataSource ds = (DataSource)ctx.getBean("dataSource");
    Connection conn = ds.getConnection();
    PreparedStatement pstmt = conn.prepareStatement(
      "insert into news_inf value(null , ? , ?)");
    pstmt.setString(1 , "瘋狂Java講義3");
    pstmt.setString(2 , "瘋狂iOS講義3");
    pstmt.executeUpdate();
    pstmt.close();
    conn.close();
  }
}