public class MyProp {
	private static MyProp instance;
	private static Object sync = new Object();
	private static java.util.Properties prop;

	public static MyProp getInstance() {
       if (null == instance) { 
           synchronized(sync) {
               if (null == instance) {
                   instance = new MyProp();
               }
           }
       }
       return instance;
   }
	
   public String getVal(String key){
	   return prop.getProperty(key);
   }
   public java.util.Vector getListProp(){
	   java.util.Vector retour = new java.util.Vector();
	   for (java.util.Enumeration e = prop.propertyNames() ; e.hasMoreElements() ;) {
	         retour.addElement(e.nextElement());
	     }
	   return retour;
   }
   public void recharge(String file){
	   synchronized(sync){
		   try{
			   prop.load( new java.io.FileInputStream(file) );
		   }catch(java.io.IOException a){
			   System.err.println("Fichier properties non trouvé");
			   a.printStackTrace();
		   }  
	   }
   }
   private MyProp(){
	   prop=new java.util.Properties();
	   this.recharge("blah.properties");
   }
}

/////////////////////////////////////////////

public class MaMain {
	public static void main(String[] args) {
		System.out.println("coucou :)");
		MyProp.getInstance().recharge("blah.properties");
		java.util.Vector maListe = MyProp.getInstance().getListProp();
		for (java.util.Enumeration e = maListe.elements() ; e.hasMoreElements() ;) 
			System.out.println(e.nextElement());
		System.out.println("ext2" + MyProp.getInstance().getVal("ext2"));
		System.out.println("ext2" + MyProp.getInstance().getVal("ext1"));
	}

}