Mina代码跟踪（1）

    protected AbstractIoService(IoSessionConfig sessionConfig, Executor executor) {
        if (sessionConfig == null) {
            throw new IllegalArgumentException("sessionConfig");
        }

        if (getTransportMetadata() == null) {
            throw new IllegalArgumentException("TransportMetadata");
        }

        if (!getTransportMetadata().getSessionConfigType().isAssignableFrom(
                sessionConfig.getClass())) {
            throw new IllegalArgumentException("sessionConfig type: "
                    + sessionConfig.getClass() + " (expected: "
                    + getTransportMetadata().getSessionConfigType() + ")");
        }

        // Create the listeners, and add a first listener : a activation listener
        // for this service, which will give information on the service state.
        listeners = new IoServiceListenerSupport(this);
        listeners.add(serviceActivationListener);

        // Stores the given session configuration
        this.sessionConfig = sessionConfig;

        // Make JVM load the exception monitor before some transports
        // change the thread context class loader.
        ExceptionMonitor.getInstance();

        if (executor == null) {
            this.executor = Executors.newCachedThreadPool();
            createdExecutor = true;
        } else {
            this.executor = executor;
            createdExecutor = false;
        }

        threadName = getClass().getSimpleName() + ‘-‘ + id.incrementAndGet();
    }

    private AbstractPollingIoAcceptor(IoSessionConfig sessionConfig,
            Executor executor, IoProcessor<S> processor,
            boolean createdProcessor) {
        super(sessionConfig, executor);

        if (processor == null) {
            throw new IllegalArgumentException("processor");
        }

        this.processor = processor;
        this.createdProcessor = createdProcessor;

        try {
            // Initialize the selector
            init();
            
            // The selector is now ready, we can switch the
            // flag to true so that incoming connection can be accepted
            selectable = true;
        } catch (RuntimeException e) {
            throw e;
        } catch (Exception e) {
            throw new RuntimeIoException("Failed to initialize.", e);
        } finally {
            if (!selectable) {
                try {
                    destroy();
                } catch (Exception e) {
                    ExceptionMonitor.getInstance().exceptionCaught(e);
                }
            }
        }
    }

    /**  AbstractIoService
     * {@inheritDoc}
     */
    public final DefaultIoFilterChainBuilder getFilterChain() {
        if (filterChainBuilder instanceof DefaultIoFilterChainBuilder) {
            return (DefaultIoFilterChainBuilder) filterChainBuilder;
        }
        
        
        throw new IllegalStateException(
                    "Current filter chain builder is not a DefaultIoFilterChainBuilder.");
    }

public class DefaultIoFilterChainBuilder implements IoFilterChainBuilder {
    
    private final static Logger LOGGER = 
        LoggerFactory.getLogger(DefaultIoFilterChainBuilder.class);
    private final List<Entry> entries;

    /**
     * Creates a new instance with an empty filter list.
     */
    public DefaultIoFilterChainBuilder() {
        entries = new CopyOnWriteArrayList<Entry>();
    }

    /**
     * Creates a new copy of the specified {@link DefaultIoFilterChainBuilder}.
     */
    public DefaultIoFilterChainBuilder(DefaultIoFilterChainBuilder filterChain) {
        if (filterChain == null) {
            throw new IllegalArgumentException("filterChain");
        }
        entries = new CopyOnWriteArrayList<Entry>(filterChain.entries);
    }

    /**
     * @see IoFilterChain#addLast(String, IoFilter)
     */
    public synchronized void addLast(String name, IoFilter filter) {
        register(entries.size(), new EntryImpl(name, filter));
    }
　　 private void register(int index, Entry e) {
        if (contains(e.getName())) {
            throw new IllegalArgumentException(
                    "Other filter is using the same name: " + e.getName());
        }

        entries.add(index, e);
    }