src/share/classes/sun/awt/AWTAutoShutdown.java

@@ -24,14 +24,17 @@
  */
 
 package sun.awt;
 
 import java.awt.AWTEvent;
+
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.IdentityHashMap;
 import java.util.Map;
+import java.util.Set;
+
 import sun.util.logging.PlatformLogger;
 
 /**
  * This class is to let AWT shutdown automatically when a user is done
  * with AWT. It tracks AWT state using the following parameters:

@@ -79,11 +82,11 @@
      * This set keeps references to all the event dispatch threads that
      * are busy at this moment, i.e. those that are not waiting for a
      * new event to appear in their event queue.
      * Access is synchronized on the main lock object.
      */
-    private final HashSet busyThreadSet = new HashSet(7);
+    private final Set<Thread> busyThreadSet = new HashSet<>(7);
 
     /**
      * Indicates whether the toolkit thread is waiting for a new native
      * event to appear or is dispatching an event.
      */

@@ -91,11 +94,11 @@
 
     /**
      * This is a map between components and their peers.
      * we should work with in under activationLock&mainLock lock.
      */
-    private final Map peerMap = new IdentityHashMap();
+    private final Map<Object, Object> peerMap = new IdentityHashMap<>();
 
     /**
      * References the alive non-daemon thread that is currently used
      * for keeping AWT from exiting.
      */

@@ -317,12 +320,14 @@
         if (!interrupted) {
             AppContext.stopEventDispatchThreads();
         }
     }
 
+    @SuppressWarnings("serial")
     static AWTEvent getShutdownEvent() {
-        return new AWTEvent(getInstance(), 0) {};
+        return new AWTEvent(getInstance(), 0) {
+        };
     }
 
     /**
      * Creates and starts a new blocker thread. Doesn't return until
      * the new blocker thread starts.