Spring Framework - @PropertySource Examples

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.*;
import org.springframework.stereotype.Component;

import java.util.Arrays;

@PropertySource("classpath:app-props.properties")
@Configuration
@ComponentScan(basePackageClasses = ArrayInjectionScanRefExample.class, useDefaultFilters = false,
                    includeFilters = @ComponentScan.Filter(
                                        type = FilterType.ASSIGNABLE_TYPE,
                                        value = ArrayInjectionScanRefExample.class))

public class ArrayInjectionScanRefExample {

    public static void main (String[] args) {
        AnnotationConfigApplicationContext context =
                            new AnnotationConfigApplicationContext(
                                                ArrayInjectionScanRefExample.class);

        TestBean bean = context.getBean(TestBean.class);
        System.out.println(Arrays.toString(bean.getRefBeanServices()));
    }

    @Component
    static class TestBean {
        private final RefBeanService[] refBeanServices;

        @Autowired // this annotation not needed starting spring 4.3
        private TestBean (RefBeanService[] refBean) {
            this.refBeanServices = refBean;
        }

        public RefBeanService[] getRefBeanServices () {
            return refBeanServices;
        }
    }

    private static interface RefBeanService {
        String getStr ();
    }

    @Component
    private static class RefBean1 implements RefBeanService {
        private String str;

        @Override
        public String getStr () {
            return str;
        }

        @Value("${some-prop1:defaultStr}")
        public void setStr (String str) {
            this.str = str;
        }

        @Override
        public String toString () {
            return "RefBean{" +
                                "str='" + str + '\'' +
                                '}';
        }
    }

    @Component
    private static class RefBean2 implements RefBeanService {
        private String str;

        @Override
        public String getStr () {
            return str;
        }

        @Value("${some-prop2:defaultStr}")
        public void setStr (String str) {
            this.str = str;
        }

        @Override
        public String toString () {
            return "RefBean{" +
                                "str='" + str + '\'' +
                                '}';
        }
    }
}

import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.core.env.ConfigurableEnvironment;

@Configuration
@PropertySource("classpath:app.properties")
public class UserPropertySourceExample {
    public static void main(String[] args) {
        AnnotationConfigApplicationContext context =
                new AnnotationConfigApplicationContext(UserPropertySourceExample.class);
        ConfigurableEnvironment env = context.getEnvironment();
        System.out.println("property sources:" + env.getPropertySources());
        String contactPerson = env.getProperty("contact-person");
        System.out.println("contact-person: " + contactPerson);
    }
}