src/java.base/share/classes/java/net/DatagramSocket.java

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 1995, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1995, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this

@@ -24,10 +24,11 @@
  */
 
 package java.net;
 
 import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.nio.channels.DatagramChannel;
 import java.security.AccessController;
 import java.security.PrivilegedExceptionAction;
 import java.util.Objects;
 import java.util.Set;

@@ -454,17 +455,21 @@
 
     /**
      * Connects the socket to a remote address for this socket. When a
      * socket is connected to a remote address, packets may only be
      * sent to or received from that address. By default a datagram
-     * socket is not connected.
+     * socket is not connected. If the socket is already closed,
+     * then this method has no effect.
      *
-     * <p>If the remote destination to which the socket is connected does not
-     * exist, or is otherwise unreachable, and if an ICMP destination unreachable
-     * packet has been received for that address, then a subsequent call to
-     * send or receive may throw a PortUnreachableException. Note, there is no
-     * guarantee that the exception will be thrown.
+     * <p> If this socket is not bound then this method will first cause the
+     * socket to be bound to an address that is assigned automatically,
+     * as if invoking the {@link #bind bind} method with a parameter of
+     * {@code null}. If the remote destination to which the socket is connected
+     * does not exist, or is otherwise unreachable, and if an ICMP destination
+     * unreachable packet has been received for that address, then a subsequent
+     * call to send or receive may throw a PortUnreachableException. Note,
+     * there is no guarantee that the exception will be thrown.
      *
      * <p> If a security manager has been installed then it is invoked to check
      * access to the remote address. Specifically, if the given {@code address}
      * is a {@link InetAddress#isMulticastAddress multicast address},
      * the security manager's {@link

@@ -496,17 +501,22 @@
      *
      * @throws SecurityException
      *         if a security manager has been installed and it does
      *         not permit access to the given remote address
      *
+     * @throws UncheckedIOException
+     *         may be thrown if connect fails, for example, if the
+     *         destination address is non-routable
+     *
      * @see #disconnect
+     * @since 1.2
      */
     public void connect(InetAddress address, int port) {
         try {
             connectInternal(address, port);
         } catch (SocketException se) {
-            throw new Error("connect failed", se);
+            throw new UncheckedIOException("connect failed", se);
         }
     }
 
     /**
      * Connects this socket to a remote socket address (IP address + port number).

@@ -543,11 +553,21 @@
 
     /**
      * Disconnects the socket. If the socket is closed or not connected,
      * then this method has no effect.
      *
+     * @apiNote If this method throws an UncheckedIOException, the socket
+     *          may be left in an unspecified state. It is strongly
+     *          recommended that the socket be closed when disconnect
+     *          fails.
+     *
+     * @throws  UncheckedIOException
+     *          may be thrown if disconnect fails to dissolve the
+     *          association and restore the socket to a consistent state.
+     *
      * @see #connect
+     * @since 1.2
      */
     public void disconnect() {
         synchronized (this) {
             if (isClosed())
                 return;