How to bind a string array of properties in Spring?

Question

I have the following in my application.properties file

some.server.url[0]=http://url
some.server.url[1]=http://otherUrl

How do I refer to the array of properties using the @Value anotation inside a @Bean method?

I am using Java 6 with Tomcat 7 and Spring boot 1.4

Answer 1

I was also having the same problem as you mentioned and it seems using index form on application.properties was not working for me either.

To solve the problem I did something like below

some.server.url = url1, url2

Then to get the those properties I simply use @Value

@Value("${some.server.url}")
private String[] urls ;

Spring automatically splits the String with comma and return you an Array. AFAIK this was introduced in Spring 4+

If you don't want comma (,) as seperator you have to use SpEL like below.

@Value("#{'${some.server.url}'.split(',')}")
private List<String> urls;

where split() accepts the seperator

Answer 2

You can use a collection.

@Value("${some.server.url}")
private List<String> urls;

You can also use a configuration class and inject the bean into your other class:

@Component
@ConfigurationProperties("some.server")
public class SomeConfiguration {
    private List<String> url;

    public List<String> getUrl() {
        return url;
    }

    public void setUrl(List<String> url) {
        this.url = url;
    }
}