src/java.base/share/classes/jdk/internal/misc/InternalLock.java

@@ -37,14 +37,14 @@
   */
  public class InternalLock {
      private static final boolean CAN_USE_INTERNAL_LOCK;
      static {
          String s = System.getProperty("jdk.io.useMonitors");
-         if (s != null && (s.isEmpty() || s.equals("true"))) {
-             CAN_USE_INTERNAL_LOCK = false;
-         } else {
+         if (s != null && s.equals("false")) {
              CAN_USE_INTERNAL_LOCK = true;
+         } else {
+             CAN_USE_INTERNAL_LOCK = false;
          }
      }
  
      private final ReentrantLock lock;