defaultiofilterchain.java

mina是以Java实现的一个开源的网络程序框架

        Entry head = this.head;
        callNextMessageSent(head, session, request);
    }

    private void callNextMessageSent(Entry entry, IoSession session,
            WriteRequest writeRequest) {
        try {
            IoFilter filter = entry.getFilter();
            NextFilter nextFilter = entry.getNextFilter();
            filter.messageSent(nextFilter, session,
                    writeRequest);
        } catch (Throwable e) {
            fireExceptionCaught(e);
        }
    }

    public void fireExceptionCaught(Throwable cause) {
        Entry head = this.head;
        callNextExceptionCaught(head, session, cause);
    }

    private void callNextExceptionCaught(Entry entry, IoSession session,
            Throwable cause) {
        // Notify the related future.
        ConnectFuture future = (ConnectFuture) session
                .removeAttribute(SESSION_CREATED_FUTURE);
        if (future == null) {
            try {
                IoFilter filter = entry.getFilter();
                NextFilter nextFilter = entry.getNextFilter();
                filter.exceptionCaught(nextFilter,
                        session, cause);
            } catch (Throwable e) {
                logger
                        .warn(
                                "Unexpected exception from exceptionCaught handler.",
                                e);
            }
        } else {
            // Please note that this place is not the only place that
            // calls ConnectFuture.setException().
            session.close(true);
            future.setException(cause);
        }
    }

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

    private void callPreviousFilterWrite(Entry entry, IoSession session,
            WriteRequest writeRequest) {
        try {
            IoFilter filter = entry.getFilter();
            NextFilter nextFilter = entry.getNextFilter();
            filter.filterWrite(nextFilter, session, writeRequest);
        } catch (Throwable e) {
            writeRequest.getFuture().setException(e);
            fireExceptionCaught(e);
        }
    }

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

    private void callPreviousFilterClose(Entry entry, IoSession session) {
        try {
            IoFilter filter = entry.getFilter();
            NextFilter nextFilter = entry.getNextFilter();
            filter.filterClose(nextFilter, session);
        } catch (Throwable e) {
            fireExceptionCaught(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) {
        return getEntry(filter) != null;
    }

    public boolean contains(Class<? extends IoFilter> filterType) {
        return getEntry(filterType) != null;
    }

    @Override
    public String toString() {
        StringBuilder buf = new StringBuilder();
        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();
    }

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

    private class HeadFilter extends IoFilterAdapter {
        @SuppressWarnings("unchecked")
        @Override
        public void filterWrite(NextFilter nextFilter, IoSession session,
                WriteRequest writeRequest) throws Exception {

            AbstractIoSession s = (AbstractIoSession) session;

            // Maintain counters.
            if (writeRequest.getMessage() instanceof IoBuffer) {
                IoBuffer buffer = (IoBuffer) writeRequest.getMessage();
                // I/O processor implementation will call buffer.reset()
                // it after the write operation is finished, because
                // the buffer will be specified with messageSent event.
                buffer.mark();
                int remaining = buffer.remaining();
                if (remaining == 0) {
                    // Zero-sized buffer means the internal message
                    // delimiter.
                    s.increaseScheduledWriteMessages();
                } else {
                    s.increaseScheduledWriteBytes(remaining);
                }
            } else {
                s.increaseScheduledWriteMessages();
            }

            s.getWriteRequestQueue().offer(s, writeRequest);
            if (!s.isWriteSuspended()) {
                s.getProcessor().flush(s);
            }
        }

        @SuppressWarnings("unchecked")
        @Override
        public void filterClose(NextFilter nextFilter, IoSession session)
                throws Exception {
            ((AbstractIoSession) session).getProcessor().remove(((AbstractIoSession) session));
        }
    }

    private static class TailFilter extends IoFilterAdapter {
        @Override
        public void sessionCreated(NextFilter nextFilter, IoSession session)
                throws Exception {
            try {
                session.getHandler().sessionCreated(session);
            } finally {
                // Notify the related future.
                ConnectFuture future = (ConnectFuture) session
                        .removeAttribute(SESSION_CREATED_FUTURE);
                if (future != null) {
                    future.setSession(session);
                }
            }
        }

        @Override
        public void sessionOpened(NextFilter nextFilter, IoSession session)
                throws Exception {
            session.getHandler().sessionOpened(session);
        }

        @Override
        public void sessionClosed(NextFilter nextFilter, IoSession session)
                throws Exception {
            AbstractIoSession s = (AbstractIoSession) session;
            try {
                s.getHandler().sessionClosed(session);
            } finally {
                try {
                    s.getWriteRequestQueue().dispose(session);
                } finally {
                    try {
                        s.getAttributeMap().dispose(session);
                    } finally {
                        try {
                            // Remove all filters.
                            session.getFilterChain().clear();
                        } finally {
                            if (s.getConfig().isUseReadOperation()) {
                                s.offerClosedReadFuture();
                            }
                        }
                    }
                }
            }
        }

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

        @Override
        public void exceptionCaught(NextFilter nextFilter, IoSession session,
                Throwable cause) throws Exception {
            AbstractIoSession s = (AbstractIoSession) session;
            try {
                s.getHandler().exceptionCaught(s, cause);
            } finally {
                if (s.getConfig().isUseReadOperation()) {
                    s.offerFailedReadFuture(cause);
                }
            }
        }

        @Override
        public void messageReceived(NextFilter nextFilter, IoSession session,
                Object message) throws Exception {
            AbstractIoSession s = (AbstractIoSession) session;
            if (!(message instanceof IoBuffer)) {
                s.increaseReadMessages(System.currentTimeMillis());
            } else if (!((IoBuffer) message).hasRemaining()) {
                s.increaseReadMessages(System.currentTimeMillis());
            }

            try {
                session.getHandler().messageReceived(s, message);
            } finally {
                if (s.getConfig().isUseReadOperation()) {
                    s.offerReadFuture(message);
                }
            }
        }

        @Override
        public void messageSent(NextFilter nextFilter, IoSession session,
                WriteRequest writeRequest) throws Exception {
            session.getHandler()
                    .messageSent(session, writeRequest.getMessage());
        }

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

        @Override
        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 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,
                        WriteRequest writeRequest) {
                    Entry nextEntry = EntryImpl.this.nextEntry;
                    callNextMessageSent(nextEntry, session, writeRequest);
                }

                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 toString() {
                	return EntryImpl.this.nextEntry.name;
                }
            };
        }

        public String getName() {
            return name;
        }

        public IoFilter getFilter() {
            return filter;
        }

        private void setFilter(IoFilter filter) {
            if (filter == null) {
                throw new NullPointerException("filter");
            }

            this.filter = filter;
        }

        public NextFilter getNextFilter() {
            return nextFilter;
        }

        @Override
        public String toString() {
        	StringBuilder sb = new StringBuilder();
        	
        	// Add the current filter
        	sb.append("('").append(getName()).append('\'');
        	
        	// Add the previous filter 
        	sb.append(", prev: '");

        	if (prevEntry != null) {
                sb.append(prevEntry.name);
                sb.append(':');
                sb.append(prevEntry.getFilter().getClass().getSimpleName());
        	} else {
            	sb.append("null");
        	}
        	
        	// Add the next filter 
        	sb.append("', next: '");

        	if (nextEntry != null) {
                sb.append(nextEntry.name);
                sb.append(':');
                sb.append(nextEntry.getFilter().getClass().getSimpleName());
        	} else {
            	sb.append("null");
        	}
        	
        	sb.append("')");
            return sb.toString();
        }

        public void addAfter(String name, IoFilter filter) {
            DefaultIoFilterChain.this.addAfter(getName(), name, filter);
        }

        public void addBefore(String name, IoFilter filter) {
            DefaultIoFilterChain.this.addBefore(getName(), name, filter);
        }

        public void remove() {
            DefaultIoFilterChain.this.remove(getName());
        }

        public void replace(IoFilter newFilter) {
            DefaultIoFilterChain.this.replace(getName(), newFilter);
        }
    }
}