Spring PropertyPlaceholderConfigurer example

Often times, most Spring developers just put the entire deployment details (database details, log file path) in XML bean configuration file as following :

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
	http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
 
	<bean id="customerDAO" class="com.mkyong.customer.dao.impl.JdbcCustomerDAO">
 
		<property name="dataSource" ref="dataSource" />
	</bean>
 
	<bean id="customerSimpleDAO" class="com.mkyong.customer.dao.impl.SimpleJdbcCustomerDAO">
 
		<property name="dataSource" ref="dataSource" />
	</bean>
 
	<bean id="dataSource"
		class="org.springframework.jdbc.datasource.DriverManagerDataSource">
 
		<property name="driverClassName" value="com.mysql.jdbc.Driver" />
		<property name="url" value="jdbc:mysql://localhost:3306/mkyongjava" />
		<property name="username" value="root" />
		<property name="password" value="password" />
	</bean>
 
</beans>

But, in a corporate environment, deployment detail is usually only can ‘touch’ by your system or database administrator, they just refuse to access your bean configuration file directly, and they will request a separate file for deployment configuration, for example, a simple properties, with deployment detail only.

PropertyPlaceholderConfigurer example

To fix it, you can use PropertyPlaceholderConfigurer class to externalize the deployment details into a properties file, and access from bean configuration file via a special format – ${variable}.

Create a properties file (database.properties), include your database details, put it into your project class path.

	jdbc.driverClassName=com.mysql.jdbc.Driver
	jdbc.url=jdbc:mysql://localhost:3306/mkyongjava
	jdbc.username=root
	jdbc.password=password

Declare a PropertyPlaceholderConfigurer in bean configuration file and map to the ‘database.properties‘ properties file you created just now.

	<bean 
		class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
 
		<property name="location">
			<value>database.properties</value>
		</property>
	</bean>

Full example

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
	http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
 
	<bean
		class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
 
		<property name="location">
			<value>database.properties</value>
		</property>
	</bean>
 
	<bean id="customerDAO" class="com.mkyong.customer.dao.impl.JdbcCustomerDAO">
 
		<property name="dataSource" ref="dataSource" />
	</bean>
 
	<bean id="customerSimpleDAO" 
                class="com.mkyong.customer.dao.impl.SimpleJdbcCustomerDAO">
 
		<property name="dataSource" ref="dataSource" />
	</bean>
 
	<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>
 
</beans>
Alternative usage
You also can use PropertyPlaceholderConfigurer to share some constant variables to all other beans. For example, define your log file location in a properties file, and access the properties value from different beans configuration files via ${log.filepath}.

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About the Author

mkyong
Founder of Mkyong.com and HostingCompass.com, love Java and open source stuff. Follow him on Twitter, or befriend him on Facebook or Google Plus. If you like my tutorials, consider make a donation to these charities.

Comments

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  • Sriram

    Hi,
    This example states how to get the values inside the configuration file. Using PropertyPlaceholderConfigurer, How to get the property values inside a java class.

  • http://yaathirigan.blogspot.com yathirigan

    If i chose to place the property file external to the application (EAR/WAR), and when the property file changes, would restart the application get the new property to be in effect ?

  • Ramesh

    I am trying to supply a runtime name of the file (my message queue.properties file differs for my different environment)

    But I am not able to set the $hostname} with the name of my hostname for spring application context to load it dynamically.

    If you have pointers for the same that would be really helpful

  • Springa Head

    You forgot to say where to deploy the properties file! Your post is pretty close to useless..

  • Pit

    just great!!. thanks

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  • http://hi raghavendra

    how to read properties file using spring…

  • http://blog.csdn.net/arvinrong Arvin Rong

    Is there any way to init a Bean’s property of Map type using properties file?I have searched for it for a whole day?but I found none. Thx a lot. Looking forward to your reply.

    • Nivesh Sengar

      Why not u can put the values in Property file like below
      key1=Value1
      key2=Value2
      key3=Value3

      And then assign this in the Spring configured XML like

      &lt;bean id = &quot;someClass&quot; class=&quot;somePackage.SomeClass&quot;&gt;
      &lt;property name=&quot;&quot;someMap&gt;
      &lt;map&gt;
      &lt;entry key=&quot;key1&quot; value=&quot;${key1}&quot; /&gt;
      &lt;entry key=&quot;key1&quot; value=&quot;${key1}&quot; /&gt;
      &lt;entry key=&quot;key1&quot; value=&quot;${key1}&quot; /&gt;
      &lt;/map&gt;
      &lt;/property&gt;
      &lt;/bean&gt;
  • Kumar

    Thanks a lot for the crisp and useful article

  • satanrulz

    can we have PropertyPlaceholderConfigurer read properties file from the file system?

    • Luis Bacca

      Yes, using file:relativepath or file:absolutepath both pointing to your properties file in the filesystem.

  • Levan

    Thanks again ))
    Got just what I wanted in seconds

  • Alex

    This example was really helpful, thanks a lot for the post. This gave me just what I needed.

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