Autowiring Issue with using Springboot PropertiesFactoryBean - spring-boot

Question

I am new to Springboot PropertiesFactoryBean and want to inject a file from classpath so that I can populate it into a Map
Location of properties file on Eclipse: src/main/resources
contents of File: simple_property.properties:
key1=value1
key2=value2
key3=value3
My ApplicationConfiguration.java looks as below:
import org.springframework.beans.factory.config.PropertiesFactoryBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
#Configuration
public class ApplicationConfiguration {
#Bean(name = "simpleMapping")
public static PropertiesFactoryBean artifactMapping() {
PropertiesFactoryBean bean = new PropertiesFactoryBean();
bean.setLocation(new ClassPathResource("simple_property.properties"));
return bean;
}
}
I have a ApplicationRunner interface for bean to be run:
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
#SpringBootApplication
public class pCli implements ApplicationRunner {
#Autowired
private SomeClass someProgram;
public static void main(String[] args) {
SpringApplication.run(pCli.class, args);
}
#Override
public void run(ApplicationArguments args) throws Exception {
someProgram.run(args.getOptionValues("param1").get(0));
}
}
I am unable to understand & proceed ahead how I can use bean to read all properties ? Example how I can get the properties into a variable of Map and access them ? (If #Autowired has already loaded the properties file from classpath then how can I access it ? )

Answer 1

Say you have your map in the property file like this,
app.number-map={KEY1:1, KEY2:2, KEY3:3}
You can use this value by injecting the property using the #Value annotation. Following is an example where the value is injected to a method. Spring expression #{${app.number-map}} will fetch the value in the properties file.
someMethod(#Value("#{${app.number-map}}")
Map<String, Integer> numberMap) {
// ...
}
Use application.properties since you're still learning. It'll make your life easy. Also, keeping a separate configuration bean would really help you to manage and access property values easily.