contrast-finder.conf should not be required

[dzc34]

Observed behaviour

if /etc/contrast-finder/contrast-finder.conf
file is missing, the webapp fails to start.

By default, Spring will throw an exception if it could not find a properties file or could not resolve a placeholder. That cause the application fails to start.

Solution

Ignoring exceptions

source: http://www.codejava.net/frameworks/spring/reading-properties-files-in-spring-with-propertyplaceholderconfigurer-bean#IgnoringExceptions

  <property name="location" value="file:///etc/contrast-finder/contrast-finder.conf"/>
+ <property name="ignoreResourceNotFound"         value="true" />
+ <property name="ignoreUnresolvablePlaceholders" value="true" />

Empty default value

source: http://blog.codeleak.pl/2015/09/placeholders-support-in-value.html

@Value("${my.string.property:}")
private String stringProperty;