how to define not mandatory property in spring?

Question

I\'m using spring 3 with PropertyPlaceholderConfigurator.

My properties code looks like as following:

@Configuration
public class MyProps {

    @Val         


        

Answer 1

You could use a default value:

@Value("${prop1:}")
public String prop1;

and spring will inject an empty string if the property isn't defined. The syntax is ${property:defaultValue}.

Answer 2

I'm not sure if it is possible to make a single property optional but surely you can force the property placeholder to ignore unresolved properties:

<context:property-placeholder ignore-unresolvable="true" ... />