class NioEndpoint标记出throw new EOFException()

tomcat服务器调试过websocket后，再发送http请求后eclipse窗口弹出一个类class NioEndpoint
这个类标记出下面的方法throw new EOFException();控制台没有输出异常 。

private int fillReadBuffer(boolean block, ByteBuffer to) throws IOException {
            int nRead;
            NioChannel channel = getSocket();
            if (block) {
                Selector selector = null;
                try {
                    selector = pool.get();
                } catch (IOException x) {
                    // Ignore
                }
                try {
                    NioEndpoint.NioSocketWrapper att = (NioEndpoint.NioSocketWrapper) channel
                            .getAttachment();
                    if (att == null) {
                        throw new IOException("Key must be cancelled.");
                    }
                    nRead = pool.read(to, channel, selector, att.getReadTimeout());
                } finally {
                    if (selector != null) {
                        pool.put(selector);
                    }
                }
            } else {
                nRead = channel.read(to);
                if (nRead == -1) {
                    throw new EOFException();
                }
            }
            return nRead;
        }

控制台的报错看一下