Question

Spring has a very handy convenience class called PropertyPlaceholderConfigurer, which takes a standard .properties file and injects values from it into your bean.xml config.

Does anyone know of a class which does exactly the same thing, and integrates with Spring in the same way, but accepts XML files for the config. Specifically, I’m thinking of Apache digester-style config files. It would be easy enough to do this, I’m just wondering if anyone already has.

Suggestions?

Answer 1

I just tested this, and it should just work.

PropertiesPlaceholderConfigurer contains a setPropertiesPersister method, so you can use your own subclass of PropertiesPersister. The default PropertiesPersister already supports properties in XML format.

Just to show you the fully working code:

JUnit 4.4 test case:

package org.nkl;  import static org.junit.Assert.assertEquals; import static org.junit.Assert.assertNotNull;  import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;  @ContextConfiguration(locations = { 'classpath:/org/nkl/test-config.xml' }) @RunWith(SpringJUnit4ClassRunner.class) public class PropertyTest {      @Autowired     private Bean bean;      @Test     public void testPropertyPlaceholderConfigurer() {         assertNotNull(bean);         assertEquals('fred', bean.getName());     } } 

The spring config file test-config.xml

<?xml version='1.0' encoding='UTF-8'?> <beans xmlns='http://www.springframework.org/schema/beans'   xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'   xmlns:context='http://www.springframework.org/schema/context'   xsi:schemaLocation=' http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd '>   <context:property-placeholder        location='classpath:/org/nkl/properties.xml' />   <bean id='bean' class='org.nkl.Bean'>     <property name='name' value='${org.nkl.name}' />   </bean> </beans> 

The XML properties file properties.xml – see here for description of usage.

<?xml version='1.0' encoding='UTF-8'?> <!DOCTYPE properties SYSTEM 'http://java.sun.com/dtd/properties.dtd'> <properties>   <entry key='org.nkl.name'>fred</entry> </properties> 

And finally the bean:

package org.nkl;  public class Bean {     private String name;     public String getName() { return name; }     public void setName(String name) { this.name = name; } } 

Hope this helps…