diff -r 52bc64277201 -r d8ed7335dadd src/java.base/share/classes/java/net/ServerSocket.java
--- a/src/java.base/share/classes/java/net/ServerSocket.java	Sat Feb 09 08:54:02 2019 +0000
+++ b/src/java.base/share/classes/java/net/ServerSocket.java	Sat Feb 09 19:16:30 2019 +0000
@@ -38,8 +38,6 @@
 import java.util.Set;
 import java.util.Collections;
 import sun.nio.ch.NioSocketImpl;
-import static java.net.SocketImpl.DelegatingImpl;
-import static java.net.SocketImpl.getDefaultSocketImpl;
 
 /**
  * This class implements server sockets. A server socket waits for
@@ -299,7 +297,7 @@
         } else {
             // No need to do a checkOldImpl() here, we know it's an up to date
             // SocketImpl!
-            impl = new SocksSocketImpl(getDefaultSocketImpl(true));
+            impl = SocketImpl.createDefaultSocketImpl(true);
         }
         if (impl != null)
             impl.setServerSocket(this);
@@ -528,23 +526,6 @@
         return s;
     }
 
-    static void prepareImpl(SocketImpl impl) {
-        if (!(impl instanceof DelegatingImpl))
-            return;
-        impl = ((DelegatingImpl)impl).delegate();
-        if (impl.address == null)
-            impl.address = new InetAddress();
-        if (impl.fd == null)
-            impl.fd = new FileDescriptor();
-    }
-
-    static SocketImpl newInstanceOfType(SocketImpl impl1, SocketImpl impl2) {
-        if (impl1 instanceof DelegatingImpl)
-            return ((DelegatingImpl)impl1).newInstance();
-        else
-            return ((DelegatingImpl)impl2).newInstance();
-    }
-
     /**
      * Subclasses of ServerSocket use this method to override accept()
      * to return their own subclass of socket.  So a FooServerSocket
@@ -569,14 +550,11 @@
         if (si == null) {
             // create a SocketImpl and accept the connection
             si = Socket.createImpl();
-            prepareImpl(si);
-            s.setImpl(si);
             impl.accept(si);
-
             try {
-                // a custom impl has accepted the connection with a Platform SocketImpl
-                if (!(impl instanceof DelegatingImpl) && (si instanceof DelegatingImpl)) {
-                    ((DelegatingImpl)si).postCustomAccept();
+                // a custom impl has accepted the connection with a NIO SocketImpl
+                if ((si instanceof NioSocketImpl) && !(impl instanceof NioSocketImpl)) {
+                    ((NioSocketImpl) si).postCustomAccept();
                 }
             } finally {
                 securityCheckAccept(si);  // closes si if permission check fails
@@ -588,18 +566,31 @@
             return;
         }
 
-        // ServerSocket or Socket is using NIO or Plain SocketImpl
-        if (impl instanceof DelegatingImpl || si instanceof DelegatingImpl) {
+        if (si instanceof SocketImpl.DelegatingImpl)
+            si = ((SocketImpl.DelegatingImpl) si).delegate();
 
+        // ServerSocket or Socket is using NIO SocketImpl
+        if (impl instanceof NioSocketImpl || si instanceof NioSocketImpl) {
             // accept connection via new SocketImpl
-
-            SocketImpl nsi = newInstanceOfType(impl, si);
-            prepareImpl(nsi);
+            NioSocketImpl nsi = new NioSocketImpl(false);
             impl.accept(nsi);
             securityCheckAccept(nsi);  // closes si if permission check fails
 
             // copy state to the existing SocketImpl and update socket state
-            ((DelegatingImpl)nsi).copyTo(si);
+            nsi.copyTo(si);
+            s.postAccept();
+            return;
+        }
+
+        // ServerSocket or Socket is using PlainSocketImpl
+        if (impl instanceof PlainSocketImpl || si instanceof PlainSocketImpl) {
+            // accept connection via new SocketImpl
+            PlainSocketImpl psi = new PlainSocketImpl();
+            impl.accept(psi);
+            securityCheckAccept(psi);  // closes si if permission check fails
+
+            // copy state to the existing SocketImpl and update socket state
+            psi.copyTo(si);
             s.postAccept();
             return;
         }
@@ -609,7 +600,8 @@
         boolean completed = false;
         try {
             si.reset();
-            prepareImpl(si);
+            si.fd = new FileDescriptor();
+            si.address = new InetAddress();
             impl.accept(si);
             securityCheckAccept(si);  // closes si if permission check fails
             completed = true;