How to access a values from application.properties in Spring Boot?

There are multiple way to access a values from application.properties in Spring Boot.

Using @Value Annotation :-

We can use the @Value annotation and access the property data from application.properties file which is use by spring bean.

  @Value(“${employee-service.url}”)

  private String url;

Using @ConfigurationProperties Annotation :-

  • It is load the configuration properties data.
  • this annotation identify the property to load.
  • Here we are use prefix that is declare in all properties file data.

     Syntax :- @ConfigurationProperties(prefix=”employee-service”)

Using @PropertySource Annotation :-

  • We are loading application.properties file data from the property source file in an Enviroment variable.
  • Here we autowired the Environment variable.

     Syntax :- org.springframework.core.env.Environment

application.properties file :-

server.port=8089

employee-service.url=javatechnote.com
employee-service.username=test
employee-service.key=test123

				
					//main class

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringHibernateApplication {

	public static void main(String[] args) {
		SpringApplication.run(SpringHibernateApplication.class, args);
	}

}
				
			
				
					// controller class

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.env.Environment;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.SpringHibernate.service.EmployeeServiceConfiguration;
import com.SpringHibernate.service.EmployeeValueFetch;

@RestController
@RequestMapping("/employee")
public class EmployeeConfigurationController {

	@Autowired
	private EmployeeServiceConfiguration employeeServiceConfiguration;

	@Autowired
	private EmployeeValueFetch employeeValueFetch;

	@Autowired
	private Environment env;

	// from @value annotation read application.properties data
	@GetMapping("/valueFetch")
	public EmployeeValueFetch fetchAll() {
		return employeeValueFetch;
	}

	// from configuration properties read application.properties data
	@GetMapping("/propData")
	public EmployeeServiceConfiguration retrieveAll() {
		test();
		return employeeServiceConfiguration;
	}

	// from Environment property source read application.properties data
	public void test() {
		String url = env.getProperty("employee-service.url");
		String userName = env.getProperty("employee-service.username");
		String key = env.getProperty("employee-service.key");
		System.out.println("fetch from enviroment :- ");
		System.out.println("url :- " + url + " ,username:- " + userName + " ,key:- " + key);
	}
}

				
			
				
					import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

//from @value read application.properties data
@Component
public class EmployeeValueFetch {

	@Value("${employee-service.url}")
	private String url;
	@Value("${employee-service.username}")
	private String username;
	@Value("${employee-service.key}")
	private String key;

   //create setter and getter of the variable	
}

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

//from ConfigurationProperties read application.properties data
@Component
@ConfigurationProperties(prefix = "employee-service")
public class EmployeeServiceConfiguration {

	private String url;

	private String username;

	private String key;

	//create setter and getter of the variable	
}

Output :-

// from @value annotation
url :- localhost:8089/employee/propData
Response :-
{
“url”: “javatechnote.com”,
“username”: “test”,
“key”: “test123”
}

// from @configurationProperties annotation
Url :- localhost:8089/employee/valueFetch
Response :-
{
“url”: “javatechnote.com”,
“username”: “test”,
“key”: “test123”
}

//fetch from enviroment :-
url :- javatechnote.com ,username:- test1 ,key:- test123