IOC With 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; } }