n o t e 1 9 . c o m

The Spring configuration files can include values from your properties files. You can easily customize this so that you can take control when the key and or the value of a property is requested. To do so, you must first tell Spring the location of your properties file:

<beans>
  <bean class="com.mycompany.MyPropertyPlaceholderConfigurer">
    <property name="locations">
       <value>classpath:my.properties</value>
    </property>
  </bean>
...

Next you must create the class:
com.mycompay.MyPropertyPlaceholderConfigurer:

package com.mycompany;
import java.util.Properties;
import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer;
import com.adobe.hs.spdf.common.PropReader;
public class MyPropertyPlaceholderConfigurer extends
   PropertyPlaceholderConfigurer {

   // process the key and then return the associated value...
   protected String resolvePlaceholder(String placeholder, Properties props) {
	String value = process-the-key-and-lookup-the-value;
	return value;
   }
}

Finally, you can use the Spring’s ${...} notation to reference values from your properties file. e.g.,

<bean id="dataSource"

    class="org.apache.commons.dbcp.BasicDataSource"

    destroy-method="close">

  <property name="driverClassName"><value>com.mysql.jdbc.Driver</value></property>

  <property name="url"><value>${mysql.server}</value></property>

  <property name="username"><value>${mysql.username}</value></property>

  <property name="password"><value>${mysql.password}</value></property>

</bean>

Possibly related posts: (automatically generated)
Declarative transactions in Spring
Accessing Property File Using Spring Framework
Spring 2.5 annotation and configuration