2727 * <p>Thread-safe Singleton class. The instance is lazily initialized and thus needs synchronization
2828 * mechanism.</p>
2929 *
30- * <p>Note: if created by reflection then a singleton will not be created but multiple options
31- * in the same classloader</p>
3230 */
3331public final class ThreadSafeLazyLoadedIvoryTower {
3432
35- private static ThreadSafeLazyLoadedIvoryTower instance ;
33+ private static volatile ThreadSafeLazyLoadedIvoryTower instance ;
3634
3735private ThreadSafeLazyLoadedIvoryTower () {
38- //protect against instantiation via reflection
36+ //Protect against instantiation via reflection
3937if (instance ==null ) {
4038instance =this ;
4139 }else {
@@ -44,13 +42,16 @@ private ThreadSafeLazyLoadedIvoryTower() {
4442 }
4543
4644/**
47- * The instancegets createdonly when it is called for first time. Lazy-loading
45+ * The instancedoesn't get createduntil the method is called forthe first time
4846 */
4947public static synchronized ThreadSafeLazyLoadedIvoryTower getInstance () {
5048if (instance ==null ) {
51- instance =new ThreadSafeLazyLoadedIvoryTower ();
49+ synchronized (ThreadSafeLazyLoadedIvoryTower .class ) {
50+ if (instance ==null ) {
51+ instance =new ThreadSafeLazyLoadedIvoryTower ();
52+ }
53+ }
5254 }
53-
5455return instance ;
5556 }
5657}