【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 
一、概述
EndPoint作为jetty-io的一个重要组成部分，是基于javaNIO的封装，用于底层网络的读写，一旦网络读写准备好，会调用相应的connection的handle方法。
二、类分析
EndPoint源码如下：
/**
*
* 一个传输端点
*
* <h3>异步方法</h3>
*/
public interface EndPoint extends Closeable
{
/* ------------------------------------------------------------ */
/**
* @return <code>EndPoint</code>绑定的本地Inet地址，如果<code>EndPoint</code>没有网络连接则为<code>null</code>
*/
InetSocketAddress getLocalAddress();
/* ------------------------------------------------------------ */
/**
* @return 上面方法的远程封装
*/
InetSocketAddress getRemoteAddress();
/* ------------------------------------------------------------ */
boolean isOpen();
/* ------------------------------------------------------------ */
long getCreatedTimeStamp();
/* ------------------------------------------------------------ */
/** Shutdown the output.
* <p>在该endpoint远程结束需要读取一次EOF时调用，意味着数据传输完毕了。可能在TCP/IP级别
* 或是协议交换时关闭。
* <p>
* If the endpoint has {@link #isInputShutdown()} true, then this call has the same effect
* as {@link #close()}.
*/
void shutdownOutput();
/* ------------------------------------------------------------ */
/** Test if output is shutdown.
* The output is shutdown by a call to {@link #shutdownOutput()}
* or {@link #close()}.
* @return true if the output is shutdown or the endpoint is closed.
*/
boolean isOutputShutdown();
/* ------------------------------------------------------------ */
/** Test if the input is shutdown.
* The input is shutdown if an EOF has been read while doing
* a {@link #fill(ByteBuffer)}. Once the input is shutdown, all calls to
* {@link #fill(ByteBuffer)} will return -1, until such time as the
* end point is close, when they will return {@link EofException}.
* @return True if the input is shutdown or the endpoint is closed.
*/
boolean isInputShutdown();
/**
* Close any backing stream associated with the endpoint
*/
@Override
void close();
/**
* Fill the passed buffer with data from this endpoint. The bytes are appended to any
* data already in the buffer by writing from the buffers limit up to it's capacity.
* The limit is updated to include the filled bytes.
*
* @param buffer The buffer to fill. The position and limit are modified during the fill. After the
* operation, the position is unchanged and the limit is increased to reflect the new data filled.
* @return an <code>int</code> value indicating the number of bytes
* filled or -1 if EOF is read or the input is shutdown.
* @throws IOException if the endpoint is closed.
*/
int fill(ByteBuffer buffer) throws IOException;
/**
* Flush data from the passed header/buffer to this endpoint. As many bytes as can be consumed
* are taken from the header/buffer position up until the buffer limit. The header/buffers position
* is updated to indicate how many bytes have been consumed.
* @param buffer the buffers to flush
* @return True IFF all the buffers have been consumed and the endpoint has flushed the data to its
* destination (ie is not buffering any data).
* @throws IOException If the endpoint is closed or output is shutdown.
*/
boolean flush(ByteBuffer... buffer) throws IOException;
/* ------------------------------------------------------------ */
/**
* @return The underlying transport object (socket, channel, etc.)
*/
Object getTransport();
/* ------------------------------------------------------------ */
/** Get the max idle time in ms.
* <p>The max idle time is the time the endpoint can be idle before
* extraordinary handling takes place.
* @return the max idle time in ms or if ms <= 0 implies an infinite timeout
*/
long getIdleTimeout();
/* ------------------------------------------------------------ */
/** Set the idle timeout.
* @param idleTimeout the idle timeout in MS. Timeout <= 0 implies an infinite timeout
*/
void setIdleTimeout(long idleTimeout);
/**
* <p>Requests callback methods to be invoked when a call to {@link #fill(ByteBuffer)} would return data or EOF.</p>
*
* @param callback the callback to call when an error occurs or we are readable.
* @throws ReadPendingException if another read operation is concurrent.
*/
void fillInterested(Callback callback) throws ReadPendingException;
/**
* @return whether {@link #fillInterested(Callback)} has been called, but {@link #fill(ByteBuffer)} has not yet
* been called
*/
boolean isFillInterested();
/**
* <p>Writes the given buffers via {@link #flush(ByteBuffer...)} and invokes callback methods when either
* all the data has been flushed or an error occurs.</p>
*
* @param callback the callback to call when an error occurs or the write completed.
* @param buffers one or more {@link ByteBuffer}s that will be flushed.
* @throws WritePendingException if another write operation is concurrent.
*/
void write(Callback callback, ByteBuffer... buffers) throws WritePendingException;
/**
* @return the {@link Connection} associated with this {@link EndPoint}
* @see #setConnection(Connection)
*/
Connection getConnection();
/**
* @param connection the {@link Connection} associated with this {@link EndPoint}
* @see #getConnection()
* @see #upgrade(Connection)
*/
void setConnection(Connection connection);
/**
* <p>Callback method invoked when this {@link EndPoint} is opened.</p>
* @see #onClose()
*/
void onOpen();
/**
* <p>Callback method invoked when this {@link EndPoint} is close.</p>
* @see #onOpen()
*/
void onClose();
/** Is the endpoint optimized for DirectBuffer usage
* @return True if direct buffers can be used optimally.
*/
boolean isOptimizedForDirectBuffers();
/** Upgrade connections.
* Close the old connection, update the endpoint and open the new connection.
* If the oldConnection is an instance of {@link Connection.UpgradeFrom} then
* a prefilled buffer is requested and passed to the newConnection if it is an instance
* of {@link Connection.UpgradeTo}
* @param newConnection The connection to upgrade to
*/
public void upgrade(Connection newConnection);
}EndPoint使用fill(Buffer buffer)方法进行数据写入，作为Connection的一个端点，用于存放内容信息。
来源：oschina
链接：https://my.oschina.net/u/271522/blog/523041