package net.sf.prefixedproperties.spring.environmentfactories;
   
   import java.util.Collections;
   import java.util.List;
   
   import org.apache.commons.lang.StringUtils;
   
   import net.sf.prefixedproperties.spring.EnvironmentFactory;
   
  /**
   * Takes the first environment from the given list of EnvironmentFactories which is not null.<br>
   * The order of the list will be the priority.<br>
   * 
   * You could build up an cascaded setup where first you look for an property in an properties file, than for an system property and than you use a static one.
   * 
   */
  public class FallbackEnvironmentFactory implements EnvironmentFactory {
  
  	private List<EnvironmentFactory> environmentFactories = Collections.emptyList();
  	
  	@Override
  	public String getEnvironment() {
  		for (EnvironmentFactory environmentFactory : getEnvironmentFactories()) {
  			String environment = environmentFactory.getEnvironment();
  			if (StringUtils.isNotBlank(environment)){
  				return environment;
  			}
  		}
  		return null;
  	}
  
  	public List<EnvironmentFactory> getEnvironmentFactories() {
  		return environmentFactories;
  	}
  
  	public void setEnvironmentFactories(List<EnvironmentFactory> environmentFactories) {
  		this.environmentFactories = environmentFactories;
  	}
  
  }