java spring - read properties file variable from xml -PropertyPlaceholderConfigurer

Java springframework xml configuration file - how to read properties file variables from spring xml :
We have to use PropertyPlaceholderConfigurer bean for this.

1).properties file location -

• src/main/resource @ maven managed project
• OR at classpath

2)The xml code to initialize/read properties file, 

I have a sample config.properties file at either of above location.

    <bean
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="locations" value="classpath:config.properties" />
    </bean>

3)config.properties file content -

server.url=http://localhost:8080/testapp/

4)Using this server.url at xml file :

We have to use - ${server.url}

eg :

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

-OR

<sometag name="someName"> ${server.url} </sometag>