abstractiofilterchain.java

apache 的一个socket框架

        try {
            entry.getFilter().exceptionCaught(entry.getNextFilter(), session,
                    cause);
        } catch (Throwable e) {
            SessionLog.warn(session,
                    "Unexpected exception from exceptionCaught handler.", e);
        }
    }

    public void fireFilterWrite(IoSession session, WriteRequest writeRequest) {
        Entry tail = this.tail;
        callPreviousFilterWrite(tail, session, writeRequest);
    }

    private void callPreviousFilterWrite(Entry entry, IoSession session,
            WriteRequest writeRequest) {
        try {
            entry.getFilter().filterWrite(entry.getNextFilter(), session,
                    writeRequest);
        } catch (Throwable e) {
            fireExceptionCaught(session, e);
        }
    }

    public void fireFilterClose(IoSession session) {
        Entry tail = this.tail;
        callPreviousFilterClose(tail, session);
    }

    private void callPreviousFilterClose(Entry entry, IoSession session) {
        try {
            entry.getFilter().filterClose(entry.getNextFilter(), session);
        } catch (Throwable e) {
            fireExceptionCaught(session, e);
        }
    }

    public List<Entry> getAll() {
        List<Entry> list = new ArrayList<Entry>();
        EntryImpl e = head.nextEntry;
        while (e != tail) {
            list.add(e);
            e = e.nextEntry;
        }

        return list;
    }

    public List<Entry> getAllReversed() {
        List<Entry> list = new ArrayList<Entry>();
        EntryImpl e = tail.prevEntry;
        while (e != head) {
            list.add(e);
            e = e.prevEntry;
        }
        return list;
    }

    public boolean contains(String name) {
        return getEntry(name) != null;
    }

    public boolean contains(IoFilter filter) {
        EntryImpl e = head.nextEntry;
        while (e != tail) {
            if (e.getFilter() == filter) {
                return true;
            }
            e = e.nextEntry;
        }
        return false;
    }

    public boolean contains(Class<? extends IoFilter> filterType) {
        EntryImpl e = head.nextEntry;
        while (e != tail) {
            if (filterType.isAssignableFrom(e.getFilter().getClass())) {
                return true;
            }
            e = e.nextEntry;
        }
        return false;
    }

    public String toString() {
        StringBuffer buf = new StringBuffer();
        buf.append("{ ");

        boolean empty = true;

        EntryImpl e = head.nextEntry;
        while (e != tail) {
            if (!empty) {
                buf.append(", ");
            } else {
                empty = false;
            }

            buf.append('(');
            buf.append(e.getName());
            buf.append(':');
            buf.append(e.getFilter());
            buf.append(')');

            e = e.nextEntry;
        }

        if (empty) {
            buf.append("empty");
        }

        buf.append(" }");

        return buf.toString();
    }

    protected void finalize() throws Throwable {
        try {
            this.clear();
        } finally {
            super.finalize();
        }
    }

    protected abstract void doWrite(IoSession session, WriteRequest writeRequest)
            throws Exception;

    protected abstract void doClose(IoSession session) throws Exception;

    private class HeadFilter extends IoFilterAdapter {
        public void sessionCreated(NextFilter nextFilter, IoSession session) {
            nextFilter.sessionCreated(session);
        }

        public void sessionOpened(NextFilter nextFilter, IoSession session) {
            nextFilter.sessionOpened(session);
        }

        public void sessionClosed(NextFilter nextFilter, IoSession session) {
            nextFilter.sessionClosed(session);
        }

        public void sessionIdle(NextFilter nextFilter, IoSession session,
                IdleStatus status) {
            nextFilter.sessionIdle(session, status);
        }

        public void exceptionCaught(NextFilter nextFilter, IoSession session,
                Throwable cause) {
            nextFilter.exceptionCaught(session, cause);
        }

        public void messageReceived(NextFilter nextFilter, IoSession session,
                Object message) {
            nextFilter.messageReceived(session, message);
        }

        public void messageSent(NextFilter nextFilter, IoSession session,
                Object message) {
            nextFilter.messageSent(session, message);
        }

        public void filterWrite(NextFilter nextFilter, IoSession session,
                WriteRequest writeRequest) throws Exception {
            if (session.getTransportType().getEnvelopeType().isAssignableFrom(
                    writeRequest.getMessage().getClass())) {
                doWrite(session, writeRequest);
            } else {
                throw new IllegalStateException(
                        "Write requests must be transformed to "
                                + session.getTransportType().getEnvelopeType()
                                + ": " + writeRequest);
            }
        }

        public void filterClose(NextFilter nextFilter, IoSession session)
                throws Exception {
            doClose(session);
        }
    }

    private static class TailFilter extends IoFilterAdapter {
        public void sessionCreated(NextFilter nextFilter, IoSession session)
                throws Exception {
            session.getHandler().sessionCreated(session);
        }

        public void sessionOpened(NextFilter nextFilter, IoSession session)
                throws Exception {
            try {
                session.getHandler().sessionOpened(session);
            } finally {
                // Notify the related ConnectFuture
                // if the session is created from SocketConnector.
                ConnectFuture future = (ConnectFuture) session
                        .removeAttribute(CONNECT_FUTURE);
                if (future != null) {
                    future.setSession(session);
                }
            }
        }

        public void sessionClosed(NextFilter nextFilter, IoSession session)
                throws Exception {
            try {
                session.getHandler().sessionClosed(session);
            } finally {
                // Remove all filters.
                session.getFilterChain().clear();
            }
        }

        public void sessionIdle(NextFilter nextFilter, IoSession session,
                IdleStatus status) throws Exception {
            session.getHandler().sessionIdle(session, status);
        }

        public void exceptionCaught(NextFilter nextFilter, IoSession session,
                Throwable cause) throws Exception {
            session.getHandler().exceptionCaught(session, cause);
        }

        public void messageReceived(NextFilter nextFilter, IoSession session,
                Object message) throws Exception {
            try {
                session.getHandler().messageReceived(session, message);
            } finally {
                ByteBufferUtil.releaseIfPossible(message);
            }
        }

        public void messageSent(NextFilter nextFilter, IoSession session,
                Object message) throws Exception {
            try {
                session.getHandler().messageSent(session, message);
            } finally {
                ByteBufferUtil.releaseIfPossible(message);
            }
        }

        public void filterWrite(NextFilter nextFilter, IoSession session,
                WriteRequest writeRequest) throws Exception {
            nextFilter.filterWrite(session, writeRequest);
        }

        public void filterClose(NextFilter nextFilter, IoSession session)
                throws Exception {
            nextFilter.filterClose(session);
        }
    }

    private class EntryImpl implements Entry {
        private EntryImpl prevEntry;

        private EntryImpl nextEntry;

        private final String name;

        private final IoFilter filter;

        private final NextFilter nextFilter;

        private EntryImpl(EntryImpl prevEntry, EntryImpl nextEntry,
                String name, IoFilter filter) {
            if (filter == null) {
                throw new NullPointerException("filter");
            }
            if (name == null) {
                throw new NullPointerException("name");
            }

            this.prevEntry = prevEntry;
            this.nextEntry = nextEntry;
            this.name = name;
            this.filter = filter;
            this.nextFilter = new NextFilter() {
                public void sessionCreated(IoSession session) {
                    Entry nextEntry = EntryImpl.this.nextEntry;
                    callNextSessionCreated(nextEntry, session);
                }

                public void sessionOpened(IoSession session) {
                    Entry nextEntry = EntryImpl.this.nextEntry;
                    callNextSessionOpened(nextEntry, session);
                }

                public void sessionClosed(IoSession session) {
                    Entry nextEntry = EntryImpl.this.nextEntry;
                    callNextSessionClosed(nextEntry, session);
                }

                public void sessionIdle(IoSession session, IdleStatus status) {
                    Entry nextEntry = EntryImpl.this.nextEntry;
                    callNextSessionIdle(nextEntry, session, status);
                }

                public void exceptionCaught(IoSession session, Throwable cause) {
                    Entry nextEntry = EntryImpl.this.nextEntry;
                    callNextExceptionCaught(nextEntry, session, cause);
                }

                public void messageReceived(IoSession session, Object message) {
                    Entry nextEntry = EntryImpl.this.nextEntry;
                    callNextMessageReceived(nextEntry, session, message);
                }

                public void messageSent(IoSession session, Object message) {
                    Entry nextEntry = EntryImpl.this.nextEntry;
                    callNextMessageSent(nextEntry, session, message);
                }

                public void filterWrite(IoSession session,
                        WriteRequest writeRequest) {
                    Entry nextEntry = EntryImpl.this.prevEntry;
                    callPreviousFilterWrite(nextEntry, session, writeRequest);
                }

                public void filterClose(IoSession session) {
                    Entry nextEntry = EntryImpl.this.prevEntry;
                    callPreviousFilterClose(nextEntry, session);
                }
            };
        }

        public String getName() {
            return name;
        }

        public IoFilter getFilter() {
            return filter;
        }

        public NextFilter getNextFilter() {
            return nextFilter;
        }

        public String toString() {
            return "(" + getName() + ':' + filter + ')';
        }
    }
}