Always Crispy

Most of the time when you are creating a Spring app, you end up packaging the XML config files with the war/jar. Sometimes though, it is quite beneficial to have a configuration file external to your built package. That allows you to configure your Spring app without having to rebuild or redeploy it; trust me, your system engineers/admins will love you for that. Using an external spring config is quite easy. You can use the import tag.

For example:
<?xml version="1.0" encoding="UTF-8"?>
<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-3.0.xsd">
   <import resource="file:/path/to/external/config.xml"/>
</beans>

The above Spring config will import /path/to/external/config.xml. Having an external file will allow you to configure beans without having to rebuilding your main war/jar. Furthermore, an external Spring config allows you to create map configurations, something that you cannot do in traditional unix style property files. Below is an example map instance you can create in your external config:

<?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:util="http://www.springframework.org/schema/util"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
                           http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd">
   <util:map id="sampleMap">
     <entry>
        <key>
           <value>Hello</value>
        </key>
           <value>World</value>
      </entry>
   </util:map>
</beans>