How to pass a Map with application.properties

Question

I have implemented some authorization in a webservice that needs be configured.

Currently the user/password combo is hardcoded into the bean configuration. I would l

Answer 1

You can use @ConfigurationProperties to have values from application.properties bound into a bean. To do so you annotate your @Bean method that creates the bean:

@Bean
@ConfigurationProperties
public BasicAuthAuthorizationInterceptor interceptor() {
    return new BasicAuthAuthorizationInterceptor();
}

As part of the bean's initialisation, any property on BasicAuthAuthorizationInterceptor will be set based on the application's environment. For example, if this is your bean's class:

public class BasicAuthAuthorizationInterceptor {

    private Map users = new HashMap();

    public Map getUsers() {
        return this.users;
    }
}

And this is your application.properties:

users.alice=alpha
users.bob=bravo

Then the users map will be populated with two entries: alice:alpha and bob:bravo.

Here's a small sample app that puts this all together:

import java.util.HashMap;
import java.util.Map;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
@EnableAutoConfiguration
@EnableConfigurationProperties
public class Application {

    public static void main(String[] args) throws Exception {
        System.out.println(SpringApplication.run(Application.class, args)
                .getBean(BasicAuthAuthorizationInterceptor.class).getUsers());
    }

    @Bean
    @ConfigurationProperties
    public BasicAuthAuthorizationInterceptor interceptor() {
        return new BasicAuthAuthorizationInterceptor();
    }

    public static class BasicAuthAuthorizationInterceptor {

        private Map users = new HashMap();

        public Map getUsers() {
            return this.users;
        }
    }
}

Take a look at the javadoc for ConfigurationProperties for more information on its various configuration options. For example, you can set a prefix to divide your configuration into a number of different namespaces:

@ConfigurationProperties(prefix="foo")

For the binding to work, you'd then have to use the same prefix on the properties declared in application.properties:

foo.users.alice=alpha
foo.users.bob=bravo