Unable to retrieve value from Properties file using Spring's @Value, @ConfigurationProperties annotations

Question

I am new to Spring Boot and using Spring Annotations. I am trying to build a sample spring boot application in which I get a value for my java property using the properties file. I am trying to use @Component & @ConfigurationProperties parameter. I followed a bunch of tutorials online and this StackOverflow article helped, but my property value is still null

Here is my code.

Looked through:-

1. unable to read properties using configurationproperties annotation

2. https://www.mkyong.com/spring/spring-propertysources-example/

My SpringBoot Application class

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;

@EnableAutoConfiguration
@SpringBootApplication
public class Main {


  public static void main(String[] args) {
    ApplicationContext context =   SpringApplication.run(Main.class, args);
    TestConf t = context.getBean(TestConf.class);
    System.out.println(t.toString());
  }
}

TestConf Class

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

@Component
@ConfigurationProperties("pres")
public class TestConf {

  private String firstName;

  public String getFirstName() {
    return firstName;
  }

  public void setFirstName(String firstName) {
    this.firstName = firstName;
  }

  public TestConf()
  {
    System.out.println("inside constructor");
    System.out.println("first name:" + firstName);
  }


  public static void main(String[] args){
    TestConf t = new TestConf();
  }

  @Override
  public String toString() {
    return "firstName:" + firstName;
  }
}

application.properties

pres.firstName=JACQUELYN

lastly my pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>phil</groupId>
  <artifactId>springTuit</artifactId>
  <version>1.0-SNAPSHOT</version>
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.2.RELEASE</version>
  </parent>

  <properties>
    <java.version>1.8</java.version>
  </properties>

  <dependencies>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>

    <!-- Optional, for bootstrap -->
    <dependency>
      <groupId>org.webjars</groupId>
      <artifactId>bootstrap</artifactId>
      <version>4.3.1</version>
    </dependency>

  </dependencies>
  <build>
    <plugins>
      <!-- Package as an executable jar/war -->
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>2.22.0</version>
      </plugin>
    </plugins>
  </build>

</project>

What is missing to retrieve the value from application.properties correctly into firstName? Does it matter where my application.properties file lies? Although it is in its traditional spot under src/main/resources and my java files are under src/main/java

Answer 1

This seems standard. However, you can try with the combination

@Component
@PropertySource("classpath:applciation.properties") 
@ConfigurationProperties 

to TestConf.Java