Is there a way to specify a default property value in Spring XML?

There is a little known feature, which makes this even better. You can use a configurable default value instead of a hard-coded one, here is an example:

config.properties:

timeout.default=30
timeout.myBean=60

context.xml:

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

<bean id="myBean" class="Test">
    <property name="timeout" value="${timeout.myBean:${timeout.default}}" />
</bean>

To use the default while still being able to easily override later, do this in config.properties:

timeout.myBean = ${timeout.default}

Spring 3 supports ${my.server.port:defaultValue} syntax.