Spring Boot application.properties value not populating

JavaSpringSpring Boot

Java Problem Overview

I have a very simple Spring Boot app that I'm trying to get working with some externalised configuration. I've tried to follow the information on the spring boot documentation however I'm hitting a road block.

When I run the app below the external configuration in the application.properties file does not get populated into the variable within the bean. I'm sure I'm doing something stupid, thanks for any suggestions.

MyBean.java (located in /src/main/java/foo/bar/)

package foo.bar;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.stereotype.Component;

@Component
public class MyBean {

    @Value("${some.prop}")
    private String prop;

    public MyBean() {
        System.out.println("================== " + prop + "================== ");
    }
}

Application.java (located in /src/main/java/foo/)

package foo;

import foo.bar.MyBean;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.SpringApplication;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class Application {

	@Autowired
    private MyBean myBean;

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

application.properties (located in /src/main/resources/)

some.prop=aabbcc

Log output when executing the Spring Boot app:

grb-macbook-pro:properties-test-app grahamrb$ java -jar ./build/libs/properties-test-app-0.1.0.jar

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.1.5.RELEASE)

2014-09-10 21:28:42.149  INFO 16554 --- [           main] foo.Application                          : Starting Application on grb-macbook-pro.local with PID 16554 (/Users/grahamrb/Dropbox/dev-projects/spring-apps/properties-test-app/build/libs/properties-test-app-0.1.0.jar started by grahamrb in /Users/grahamrb/Dropbox/dev-projects/spring-apps/properties-test-app)
2014-09-10 21:28:42.196  INFO 16554 --- [           main] ationConfigEmbeddedWebApplicationContext : Refreshing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@67e38ec8: startup date [Wed Sep 10 21:28:42 EST 2014]; root of context hierarchy
2014-09-10 21:28:42.828  INFO 16554 --- [           main] o.s.b.f.s.DefaultListableBeanFactory     : Overriding bean definition for bean 'beanNameViewResolver': replacing [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.boot.autoconfigure.web.ErrorMvcAutoConfiguration$WhitelabelErrorViewConfiguration; factoryMethodName=beanNameViewResolver; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/web/ErrorMvcAutoConfiguration$WhitelabelErrorViewConfiguration.class]] with [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter; factoryMethodName=beanNameViewResolver; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/web/WebMvcAutoConfiguration$WebMvcAutoConfigurationAdapter.class]]
2014-09-10 21:28:43.592  INFO 16554 --- [           main] .t.TomcatEmbeddedServletContainerFactory : Server initialized with port: 8080
2014-09-10 21:28:43.784  INFO 16554 --- [           main] o.apache.catalina.core.StandardService   : Starting service Tomcat
2014-09-10 21:28:43.785  INFO 16554 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/7.0.54
2014-09-10 21:28:43.889  INFO 16554 --- [ost-startStop-1] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2014-09-10 21:28:43.889  INFO 16554 --- [ost-startStop-1] o.s.web.context.ContextLoader            : Root WebApplicationContext: initialization completed in 1695 ms
2014-09-10 21:28:44.391  INFO 16554 --- [ost-startStop-1] o.s.b.c.e.ServletRegistrationBean        : Mapping servlet: 'dispatcherServlet' to [/]
2014-09-10 21:28:44.393  INFO 16554 --- [ost-startStop-1] o.s.b.c.embedded.FilterRegistrationBean  : Mapping filter: 'hiddenHttpMethodFilter' to: [/*]
================== null==================
2014-09-10 21:28:44.606  INFO 16554 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2014-09-10 21:28:44.679  INFO 16554 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],methods=[],params=[],headers=[],consumes=[],produces=[],custom=[]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2014-09-10 21:28:44.679  INFO 16554 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],methods=[],params=[],headers=[],consumes=[],produces=[text/html],custom=[]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest)
2014-09-10 21:28:44.716  INFO 16554 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2014-09-10 21:28:44.716  INFO 16554 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2014-09-10 21:28:44.902  INFO 16554 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2014-09-10 21:28:44.963  INFO 16554 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080/http
2014-09-10 21:28:44.965  INFO 16554 --- [           main] foo.Application                          : Started Application in 3.316 seconds (JVM running for 3.822)
^C2014-09-10 21:28:54.223  INFO 16554 --- [       Thread-2] ationConfigEmbeddedWebApplicationContext : Closing org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@67e38ec8: startup date [Wed Sep 10 21:28:42 EST 2014]; root of context hierarchy
2014-09-10 21:28:54.225  INFO 16554 --- [       Thread-2] o.s.j.e.a.AnnotationMBeanExporter        : Unregistering JMX-exposed beans on shutdown

Java Solutions

Solution 1 - Java

The way you are performing the injection of the property will not work, because the injection is done after the constructor is called.

You need to do one of the following:

Better solution

@Component
public class MyBean {

    private final String prop;

    @Autowired
    public MyBean(@Value("${some.prop}") String prop) {
        this.prop = prop;
        System.out.println("================== " + prop + "================== ");
    }
}

Solution that will work but is less testable and slightly less readable

@Component
public class MyBean {

    @Value("${some.prop}")
    private String prop;

    public MyBean() {

    }
 
    @PostConstruct
    public void init() {
        System.out.println("================== " + prop + "================== ");
    }
}

Also note that is not Spring Boot specific but applies to any Spring application

Solution 2 - Java

The user "geoand" is right in pointing out the reasons here and giving a solution. But a better approach is to encapsulate your configuration into a separate class, say SystemContiguration java class and then inject this class into what ever services you want to use those fields.

Your current way(@grahamrb) of reading config values directly into services is error prone and would cause refactoring headaches if config setting name is changed.

Solution 3 - Java

This answer may or may not be applicable to your case ... Once I had a similar symptom and I double checked my code many times and all looked good but the @Value setting was still not taking effect. And then after doing File > Invalidate Cache / Restart with my IntelliJ (my IDE), the problem went away ...

This is very easy to try so may be worth a shot

Solution 4 - Java

Actually, For me below works fine.

@Component
public class MyBean {

   public static String prop;

   @Value("${some.prop}")
   public void setProp(String prop) {
	  this.prop= prop;
   }

   public MyBean() {

   }

   @PostConstruct
   public void init() {
      System.out.println("================== " + prop + "================== ");
   }

}

Now whereever i want, just invoke

MyBean.prop

it will return value.

Solution 5 - Java

Using Environment class we can get application. Properties values

@Autowired,

private Environment env;

and access using

String password =env.getProperty(your property key);

Solution 6 - Java

follow these steps. 1:- create your configuration class like below you can see

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.beans.factory.annotation.Value;

@Configuration
public class YourConfiguration{

    // passing the key which you set in application.properties
	@Value("${some.pro}")
	private String somePro;

   // getting the value from that key which you set in application.properties
	@Bean
	public String getsomePro() {
		return somePro;
	}
}

2:- when you have a configuration class then inject in the variable from a configuration where you need.

@Component
public class YourService {

	@Autowired
	private String getsomePro;

	// now you have a value in getsomePro variable automatically.
}

Solution 7 - Java

If you're working in a large multi-module project, with several different application.properties files, then try adding your value to the parent project's property file.

If you are unsure which is your parent project, check your project's pom.xml file, for a <parent> tag.

This solved the issue for me.

Solution 8 - Java

You can use Environment Class to get data :

@Autowired
private Environment env;
String prop= env.getProperty('some.prop');

Solution 9 - Java

Simplest solution that solved this issue for me:

Add @PropertySource annotation to the Component/Service that needs to populate @Value field:

@Service
@PropertySource("classpath:myproperties.properties")
public class MyService {

  @Value("${some.prop}")
  private String someProperty;

  // some logic...
}

Make sure to add the properties file to the resource folder of the same module as your Service/Component.

Solution 10 - Java

You are getting this error because you are initializing the class with new keyword. To solve this, first you need to create the configuration class and under this class you need to create the bean of this class. When you will call it by using bean then it will work..

package ca.testing;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import java.sql.Connection;
import java.sql.DriverManager;

@Component
@PropertySource("db.properties")
public class ConnectionFactory {
    @Value("${jdbc.user}")
    private String user;
    @Value("${jdbc.password}")
    private String password;
    @Value("${jdbc.url}")
    private String url;
    Connection connection;

    public Connection getConnection(){
        try {
            connection = DriverManager.getConnection(url, user, password);
            System.out.println(connection.hashCode());
        }catch (Exception e){
            System.out.println(e);
        }
        return connection;
    }

    public static void main(String[] args) {
        AnnotationConfigApplicationContext context= new AnnotationConfigApplicationContext(Config.class);
        ConnectionFactory connectionFactory= context.getBean(ConnectionFactory.class);
        connectionFactory.getConnection();
    }
}
Categories
Recommended Java Solutions
Recommended Spring Solutions
Recommended Spring Boot Solutions

Previous Solution:

bootstrap modal removes scroll bar

JavascriptTwitter BootstrapModal Dialog

Next Solution:

Enterprise App Update Distribution on iOS 8

IosXcodeIos8Enterprise Distribution

Attributions

All content for this solution is sourced from the original question on Stackoverflow.

The content on this page is licensed under the Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) license.

Content TypeOriginal AuthorOriginal Content on Stackoverflow
QuestiongrahamrbView Question on Stackoverflow
Solution 1 - JavageoandView Answer on Stackoverflow
Solution 2 - JavaAmitKumarView Answer on Stackoverflow
Solution 3 - JavaleeyuiwahView Answer on Stackoverflow
Solution 4 - JavaRaj MohamadView Answer on Stackoverflow
Solution 5 - Javaramakotireddy nagireddyView Answer on Stackoverflow
Solution 6 - JavaFazle SubhanView Answer on Stackoverflow
Solution 7 - JavaJanac MeenaView Answer on Stackoverflow
Solution 8 - JavaAbd AbughazalehView Answer on Stackoverflow
Solution 9 - JavasolujicView Answer on Stackoverflow
Solution 10 - JavaManinderView Answer on Stackoverflow