@ConfigurationProperties

package com.in28minutes.springboot.learnspringboot;

import java.util.Arrays;
import java.util.List; // Import List class

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class CurrencyConfigurationController {
	
	@Autowired
	private CurrencyServiceConfigyration configyration;
	
	@RequestMapping("/currency-configyration") 
	public CurrencyServiceConfigyration retrieveAllCourses(){
		return configyration;
	}
}

package com.in28minutes.springboot.learnspringboot;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

@ConfigurationProperties(prefix = "currency-service")
@Component
public class CurrencyServiceConfigyration {
	//currency-service.url=
	//currency-service.username=
	//currency-service.key=
	private String url;
	private String username;
	private String key;
	
	public String getUrl() {
		return url;
	}
	public void setUrl(String url) {
		this.url = url;
	}
	public String getUsername() {
		return username;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getKey() {
		return key;
	}
	public void setKey(String key) {
		this.key = key;
	}
}

logging.level.org.springframework=debug
spring.profiles.active=trace

	currency-service.url=http://default.in28minytes.com
	currency-service.username=defaultusername
	currency-service.key=defaultkey