IOC With Properties File : Properties File « Spring « Java Tutorial

1. Java Tutorial
2. Spring
3. Properties File

File: context.properties

source.(class)=SimpleMessageData
destination.(class)=StdoutMessageReporter
service.(class)=DefaultMessageService
service.source(ref)=source
service.destination(ref)=destination

File: Main.java

import org.springframework.beans.factory.support.BeanDefinitionReader;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.beans.factory.support.PropertiesBeanDefinitionReader;
import org.springframework.core.io.ClassPathResource;
import org.springframework.util.Assert;

public class Main {

  public static void main(String[] args) throws Exception {
    
      
      DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
      BeanDefinitionReader reader = new PropertiesBeanDefinitionReader(bf);
      reader.loadBeanDefinitions(new ClassPathResource("context.properties"));
   
      MessageService service = (MessageService) bf.getBean("service");

    DependantComponent dc = new DependantComponent(service);
    dc.run();
    
  }
}
class DependantComponent {
  private MessageService service;

  public DependantComponent(MessageService service) {
      Assert.notNull(service, "The 'service' argument must not be null.");
      this.service = service;
  }

  public void run() {
      this.service.execute();
  }
}

interface MessageService {

  void execute();

}
class DefaultMessageService implements MessageService {
  private MessageData source;
  private MessageReporter destination;

  public void execute() {
      this.destination.write(this.source.getMessage());
  }

  public void setSource(MessageData source) {
      this.source = source;
  }

  public void setDestination(MessageReporter destination) {
      this.destination = destination;
  }
}

interface MessageReporter {

  void write(String message);

}

interface MessageData {

  String getMessage();

}

class StdoutMessageReporter implements MessageReporter {

  public void write(String message) {
    System.out.println(message);
  }
}

class SimpleMessageData implements MessageData {
  private final String message;

  public SimpleMessageData() {
    this("Hello, world");
  }

  public SimpleMessageData(String message) {
    this.message = message;
  }

  public String getMessage() {
    return this.message;
  }
}

28.10.Properties File
	28.10.1.	Spring Properties File Base Data Injection
	28.10.2.	Property File based Bean Injection
	28.10.3.	Properties File Based Spring Bean
	28.10.4.	IOC With Properties File