Spring Boot - inject map from application.yml

Below solution is a shorthand for @Andy Wilkinson's solution, except that it doesn't have to use a separate class or on a @Bean annotated method.

application.yml:

input:
  name: raja
  age: 12
  somedata:
    abcd: 1 
    bcbd: 2
    cdbd: 3

SomeComponent.java:

@Component
@EnableConfigurationProperties
@ConfigurationProperties(prefix = "input")
class SomeComponent {

    @Value("${input.name}")
    private String name;

    @Value("${input.age}")
    private Integer age;

    private HashMap<String, Integer> somedata;

    public HashMap<String, Integer> getSomedata() {
        return somedata;
    }

    public void setSomedata(HashMap<String, Integer> somedata) {
        this.somedata = somedata;
    }

}

We can club both @Value annotation and @ConfigurationProperties, no issues. But getters and setters are important and @EnableConfigurationProperties is must to have the @ConfigurationProperties to work.

I tried this idea from groovy solution provided by @Szymon Stepniak, thought it will be useful for someone.

You can have a map injected using @ConfigurationProperties:

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 MapBindingSample {

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

    @Bean
    @ConfigurationProperties
    public Test test() {
        return new Test();
    }

    public static class Test {

        private Map<String, Object> info = new HashMap<String, Object>();

        public Map<String, Object> getInfo() {
            return this.info;
        }
    }
}

Running this with the yaml in the question produces:

{build={artifact=${project.artifactId}, version=${project.version}, name=${project.name}, description=${project.description}}}

There are various options for setting a prefix, controlling how missing properties are handled, etc. See the javadoc for more information.