Summary
-------

The DatagramChannel connect, send, and receive methods may implicitly bind the channel, if not already bound. If a security manager has been installed and its checkListen method denies the operation, a SecurityException will be thrown. This behaviour is not described in the javadoc.

Problem
-------

The current spec of DatagramChannel connect, receive, and send methods do not list all the cases in which a SecurityException might be thrown. In particular, the fact that a permission check is performed in case an implicit bind occurs is not documented. In practice, an implicit bind operation is unlikely to fail as binding using port 0 is part of the permissions granted by default. However the case may arise if a custom security manager overriding the SecurityManager::checkListen method has been installed.

Solution
--------

Update the spec to make it clear that SecurityException can be thrown if a security manager's checkListen call denies the operation.

Specification
-------------

DatagramChannel::connect

          * @throws  SecurityException
    -     *          If a security manager has been installed
    -     *          and it does not permit access to the given remote address
    +     *          If a security manager has been installed and it does not
    +     *          permit access to the given remote address, or if unbound,
    +     *          the security manager {@link SecurityManager#checkListen checkListen}
    +     *          method denies the operation
          *
          * @throws  IOException
          *          If some other I/O error occurs
          */
         public abstract DatagramChannel connect(SocketAddress remote)

DatagramChannel::receive

    +     * @throws  SecurityException
    +     *          If unbound, and a security manager has been installed and
    +     *          its {@link SecurityManager#checkListen checkListen} method
    +     *          denies the operation
    +     *
          * @throws  IOException
          *          If some other I/O error occurs
          */
         public abstract SocketAddress receive(ByteBuffer dst) throws IOException;

DatagramChannel::send

          * @throws  SecurityException
    -     *          If a security manager has been installed
    -     *          and it does not permit datagrams to be sent
    -     *          to the given address
    +     *          If a security manager has been installed and it does not permit
    +     *          datagrams to be sent to the given address, or if unbound, and
    +     *          the security manager's {@link SecurityManager#checkListen checkListen}
    +     *          method denies the operation
          *
          * @throws  IOException
          *          If some other I/O error occurs
          */
         public abstract int send(ByteBuffer src, SocketAddress target)