java - 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 {

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

    ...
}

If I do not have a prop1 in my .properties file the spring fails to initialize it's context.

The question is how can I define that this property is not mandatory? some annotation, configuration?

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}.