diff -r b3a91113026c -r c10ab96dcf41 jdk/src/share/classes/sun/nio/ch/DatagramChannelImpl.java
--- a/jdk/src/share/classes/sun/nio/ch/DatagramChannelImpl.java	Wed Jul 05 18:09:43 2017 +0200
+++ b/jdk/src/share/classes/sun/nio/ch/DatagramChannelImpl.java	Thu Jun 07 18:05:09 2012 -0700
@@ -32,13 +32,15 @@
 import java.nio.channels.*;
 import java.nio.channels.spi.*;
 import java.util.*;
+import javax.tools.annotation.GenerateNativeHeader;
 import sun.net.ResourceManager;
 
-
 /**
  * An implementation of DatagramChannels.
  */
 
+/* No native methods here, but the constants are needed in the supporting JNI code */
+@GenerateNativeHeader
 class DatagramChannelImpl
     extends DatagramChannel
     implements SelChImpl