SocketWrapperBase (Apache Tomcat 10.1.55 API Documentation)
Description: declaration: package: org.apache.tomcat.util.net, class: SocketWrapperBase

# Class SocketWrapperBase<E>

java.lang.Object
org.apache.tomcat.util.net.SocketWrapperBase<E>

Direct Known Subclasses:
  `Nio2Endpoint.Nio2SocketWrapper, NioEndpoint.NioSocketWrapper`

public abstract class SocketWrapperBase<E> extends Object

- ## Nested Class Summary

  Nested Classes
  Modifier and Type
  Class
  Description
  `static enum`
  `SocketWrapperBase.BlockingMode`
  `static interface`
  `SocketWrapperBase.CompletionCheck`
  `static enum`
  `SocketWrapperBase.CompletionHandlerCall`
  `static enum`
  `SocketWrapperBase.CompletionState`
  `protected class`
  `SocketWrapperBase.OperationState<A>`
  Internal state tracker for vectored operations.
  `protected class`
  `SocketWrapperBase.VectoredIOCompletionHandler<A>`
  Completion handler for vectored operations.

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `protected int`
  `bufferedWriteSize`
  The max size of the individual buffered write buffers
  `protected final AtomicBoolean`
  `closed`
  `static final SocketWrapperBase.CompletionCheck`
  `COMPLETE_READ`
  This utility CompletionCheck will cause the completion handler to be called once the given buffers are full.
  `static final SocketWrapperBase.CompletionCheck`
  `COMPLETE_READ_WITH_COMPLETION`
  This utility CompletionCheck will cause the completion handler to be called once the given buffers are full.
  `static final SocketWrapperBase.CompletionCheck`
  `COMPLETE_WRITE`
  This utility CompletionCheck will cause the write to fully write all remaining data.
  `static final SocketWrapperBase.CompletionCheck`
  `COMPLETE_WRITE_WITH_COMPLETION`
  This utility CompletionCheck will cause the write to fully write all remaining data.
  `protected String`
  `localAddr`
  `protected String`
  `localName`
  `protected int`
  `localPort`
  `protected final WriteBuffer`
  `nonBlockingWriteBuffer`
  Additional buffer used for non-blocking writes.
  `protected IOException`
  `previousIOException`
  `static final SocketWrapperBase.CompletionCheck`
  `READ_DATA`
  This utility CompletionCheck will cause the completion handler to be called once some data has been read.
  `protected SocketWrapperBase<E>.OperationState<?>`
  `readOperation`
  `protected final Semaphore`
  `readPending`
  `protected String`
  `remoteAddr`
  `protected String`
  `remoteHost`
  `protected int`
  `remotePort`
  `protected ServletConnection`
  `servletConnection`
  `protected static final StringManager`
  `sm`
  `protected String`
  `sniHostName`
  `protected SocketBufferHandler`
  `socketBufferHandler`
  The buffers used for communicating with the socket.
  `protected SocketWrapperBase<E>.OperationState<?>`
  `writeOperation`
  `protected final Semaphore`
  `writePending`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `SocketWrapperBase(E socket, AbstractEndpoint<E,?> endpoint)`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `protected static boolean`
  `buffersArrayHasRemaining(ByteBuffer[] buffers, int offset, int length)`
  `boolean`
  `canWrite()`
  `void`
  `checkError()`
  `void`
  `close()`
  Close the socket wrapper.
  `abstract SendfileDataBase`
  `createSendfileData(String filename, long pos, long length)`
  `int`
  `decrementKeepAlive()`
  `abstract void`
  `doClientAuth(SSLSupport sslSupport)`
  Require the client to perform CLIENT-CERT authentication if it hasn't already done so.
  `protected abstract void`
  `doClose()`
  Perform the actual close.
  `protected void`
  `doWrite(boolean block)`
  Write the contents of the socketWriteBuffer to the socket.
  `protected abstract void`
  `doWrite(boolean block, ByteBuffer from)`
  Write the contents of the ByteBuffer to the socket.
  `void`
  `execute(Runnable runnable)`
  Transfers processing to a container thread.
  `boolean`
  `flush(boolean block)`
  Writes as much data as possible from any that remains in the buffers.
  `protected void`
  `flushBlocking()`
  Writes all remaining data from the buffers and blocks until the write is complete.
  `protected abstract boolean`
  `flushNonBlocking()`
  Writes as much data as possible from any that remains in the buffers.
  `Object`
  `getCurrentProcessor()`
  `protected AbstractEndpoint<E,?>`
  `getEndpoint()`
  `IOException`
  `getError()`
  `String`
  `getLocalAddr()`
  `String`
  `getLocalName()`
  `int`
  `getLocalPort()`
  `Lock`
  `getLock()`
  `String`
  `getNegotiatedProtocol()`
  `long`
  `getReadTimeout()`
  `String`
  `getRemoteAddr()`
  `String`
  `getRemoteHost()`
  `int`
  `getRemotePort()`
  `ServletConnection`
  `getServletConnection(String protocol, String protocolConnectionId)`
  `String`
  `getSniHostName()`
  `E`
  `getSocket()`
  `SocketBufferHandler`
  `getSocketBufferHandler()`
  `abstract SSLSupport`
  `getSslSupport()`
  Obtain an SSLSupport instance for this socket.
  `long`
  `getWriteTimeout()`
  `boolean`
  `hasAsyncIO()`
  Allows using NIO2 style read/write.
  `boolean`
  `hasDataToRead()`
  `boolean`
  `hasDataToWrite()`
  `boolean`
  `hasPerOperationTimeout()`
  Allows indicating if the connector supports per operation timeout.
  `boolean`
  `isClosed()`
  `boolean`
  `isReadPending()`
  Allows checking if an asynchronous read operation is currently pending.
  `abstract boolean`
  `isReadyForRead()`
  `boolean`
  `isReadyForWrite()`
  Checks to see if there are any writes pending and if there are calls `registerWriteInterest()` to trigger a callback once the pending writes have completed.
  `boolean`
  `isWritePending()`
  Allows checking if an asynchronous write operation is currently pending.
  `boolean`
  `needSemaphores()`
  Allows indicating if the connector needs semaphores.
  `protected abstract <A> SocketWrapperBase<E>.OperationState<A>`
  `newOperationState(boolean read, ByteBuffer[] buffers, int offset, int length, SocketWrapperBase.BlockingMode block, long timeout, TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, CompletionHandler<Long, ? super A> handler, Semaphore semaphore, SocketWrapperBase<E>.VectoredIOCompletionHandler<A> completion)`
  `protected abstract void`
  `populateLocalAddr()`
  `protected abstract void`
  `populateLocalName()`
  `protected abstract void`
  `populateLocalPort()`
  `protected int`
  `populateReadBuffer(byte[] b, int off, int len)`
  `protected int`
  `populateReadBuffer(ByteBuffer to)`
  `protected abstract void`
  `populateRemoteAddr()`
  `protected abstract void`
  `populateRemoteHost()`
  `protected abstract void`
  `populateRemotePort()`
  `abstract SendfileState`
  `processSendfile(SendfileDataBase sendfileData)`
  Starts the sendfile process.
  `void`
  `processSocket(SocketEvent socketStatus, boolean dispatch)`
  `abstract int`
  `read(boolean block, byte[] b, int off, int len)`
  `abstract int`
  `read(boolean block, ByteBuffer to)`
  `final <A> SocketWrapperBase.CompletionState`
  `read(long timeout, TimeUnit unit, A attachment, CompletionHandler<Long, ? super A> handler, ByteBuffer... dsts)`
  Scatter read.
  `final <A> SocketWrapperBase.CompletionState`
  `read(ByteBuffer[] dsts, int offset, int length, SocketWrapperBase.BlockingMode block, long timeout, TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, CompletionHandler<Long, ? super A> handler)`
  Scatter read.
  `final <A> SocketWrapperBase.CompletionState`
  `read(SocketWrapperBase.BlockingMode block, long timeout, TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, CompletionHandler<Long, ? super A> handler, ByteBuffer... dsts)`
  Scatter read.
  `abstract void`
  `registerReadInterest()`
  `abstract void`
  `registerWriteInterest()`
  `protected void`
  `reset(E closedSocket)`
  `abstract void`
  `setAppReadBufHandler(ApplicationBufferHandler handler)`
  `void`
  `setCurrentProcessor(Object currentProcessor)`
  `void`
  `setError(IOException error)`
  `void`
  `setKeepAliveLeft(int keepAliveLeft)`
  `void`
  `setNegotiatedProtocol(String negotiatedProtocol)`
  `void`
  `setReadTimeout(long readTimeout)`
  Set the timeout for reading.
  `void`
  `setSniHostName(String sniHostName)`
  `void`
  `setWriteTimeout(long writeTimeout)`
  Set the timeout for writing.
  `Object`
  `takeCurrentProcessor()`
  `String`
  `toString()`
  Overridden for debug purposes.
  `protected static int`
  `transfer(byte[] from, int offset, int length, ByteBuffer to)`
  `protected static int`
  `transfer(ByteBuffer from, ByteBuffer to)`
  `void`
  `unRead(ByteBuffer returnedInput)`
  Return input that has been read to the input buffer for re-reading by the correct component.
  `protected final <A> SocketWrapperBase.CompletionState`
  `vectoredOperation(boolean read, ByteBuffer[] buffers, int offset, int length, SocketWrapperBase.BlockingMode block, long timeout, TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, CompletionHandler<Long, ? super A> handler)`
  Vectored operation.
  `final void`
  `write(boolean block, byte[] buf, int off, int len)`
  Writes the provided data to the socket write buffer.
  `final void`
  `write(boolean block, ByteBuffer from)`
  Writes the provided data to the socket write buffer.
  `final <A> SocketWrapperBase.CompletionState`
  `write(long timeout, TimeUnit unit, A attachment, CompletionHandler<Long, ? super A> handler, ByteBuffer... srcs)`
  Gather write.
  `final <A> SocketWrapperBase.CompletionState`
  `write(ByteBuffer[] srcs, int offset, int length, SocketWrapperBase.BlockingMode block, long timeout, TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, CompletionHandler<Long, ? super A> handler)`
  Gather write.
  `final <A> SocketWrapperBase.CompletionState`
  `write(SocketWrapperBase.BlockingMode block, long timeout, TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, CompletionHandler<Long, ? super A> handler, ByteBuffer... srcs)`
  Gather write.
  `protected void`
  `writeBlocking(byte[] buf, int off, int len)`
  Writes the provided data to the socket write buffer.
  `protected void`
  `writeBlocking(ByteBuffer from)`
  Writes the provided data to the socket write buffer.
  `protected void`
  `writeNonBlocking(byte[] buf, int off, int len)`
  Transfers the data to the socket write buffer (writing that data to the socket if the buffer fills up using a non-blocking write) until either all the data has been transferred and space remains in the socket write buffer or a non-blocking write leaves data in the socket write buffer.
  `protected void`
  `writeNonBlocking(ByteBuffer from)`
  Transfers the data to the socket write buffer (writing that data to the socket if the buffer fills up using a non-blocking write) until either all the data has been transferred and space remains in the socket write buffer or a non-blocking write leaves data in the socket write buffer.
  `protected void`
  `writeNonBlockingInternal(ByteBuffer from)`
  Separate method so it can be re-used by the socket write buffer to write data to the network

  ### Methods inherited from class Object

  `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- ## Field Details

  - ### sm

    protected static final StringManager sm

  - ### closed

    protected final AtomicBoolean closed

  - ### previousIOException

    protected volatile IOException previousIOException

  - ### localAddr

    protected String localAddr

  - ### localName

    protected String localName

  - ### localPort

    protected int localPort

  - ### remoteAddr

    protected String remoteAddr

  - ### remoteHost

    protected String remoteHost

  - ### remotePort

    protected int remotePort

  - ### servletConnection

    protected volatile ServletConnection servletConnection

  - ### sniHostName

    protected String sniHostName

  - ### socketBufferHandler

    protected volatile SocketBufferHandler socketBufferHandler
    The buffers used for communicating with the socket.

  - ### bufferedWriteSize

    protected int bufferedWriteSize
    The max size of the individual buffered write buffers

  - ### nonBlockingWriteBuffer

    protected final WriteBuffer nonBlockingWriteBuffer
    Additional buffer used for non-blocking writes. Non-blocking writes need to return immediately even if the data cannot be written immediately but the socket buffer may not be big enough to hold all of the unwritten data. This structure provides an additional buffer to hold the data until it can be written. Not that while the Servlet API only allows one non-blocking write at a time, due to buffering and the possible need to write HTTP headers, this layer may see multiple writes.

  - ### readPending

    protected final Semaphore readPending

  - ### readOperation

    protected volatile SocketWrapperBase<E>.OperationState<?> readOperation

  - ### writePending

    protected final Semaphore writePending

  - ### writeOperation

    protected volatile SocketWrapperBase<E>.OperationState<?> writeOperation

  - ### COMPLETE_WRITE

    public static final SocketWrapperBase.CompletionCheck COMPLETE_WRITE
    This utility CompletionCheck will cause the write to fully write all remaining data. If the operation completes inline, the completion handler will not be called.

  - ### COMPLETE_WRITE_WITH_COMPLETION

    public static final SocketWrapperBase.CompletionCheck COMPLETE_WRITE_WITH_COMPLETION
    This utility CompletionCheck will cause the write to fully write all remaining data. The completion handler will then be called.

  - ### READ_DATA

    public static final SocketWrapperBase.CompletionCheck READ_DATA
    This utility CompletionCheck will cause the completion handler to be called once some data has been read. If the operation completes inline, the completion handler will not be called.

  - ### COMPLETE_READ_WITH_COMPLETION

    public static final SocketWrapperBase.CompletionCheck COMPLETE_READ_WITH_COMPLETION
    This utility CompletionCheck will cause the completion handler to be called once the given buffers are full. The completion handler will then be called.

  - ### COMPLETE_READ

    public static final SocketWrapperBase.CompletionCheck COMPLETE_READ
    This utility CompletionCheck will cause the completion handler to be called once the given buffers are full. If the operation completes inline, the completion handler will not be called.

- ## Constructor Details

  - ### SocketWrapperBase

    public SocketWrapperBase(E socket, AbstractEndpoint<E,?> endpoint)

- ## Method Details

  - ### getSocket

    public E getSocket()

  - ### reset

    protected void reset(E closedSocket)

  - ### getEndpoint

    protected AbstractEndpoint<E,?> getEndpoint()

  - ### getLock

    public Lock getLock()

  - ### getCurrentProcessor

    public Object getCurrentProcessor()

  - ### setCurrentProcessor

    public void setCurrentProcessor(Object currentProcessor)

  - ### takeCurrentProcessor

    public Object takeCurrentProcessor()

  - ### execute

    public void execute(Runnable runnable)
    Transfers processing to a container thread.
    Parameters:
      `runnable` - The actions to process on a container thread
    Throws:
      `RejectedExecutionException` - If the runnable cannot be executed

  - ### getError

    public IOException getError()

  - ### setError

    public void setError(IOException error)

  - ### checkError

    public void checkError() throws IOException
    Throws:
      `IOException`

  - ### getNegotiatedProtocol

    public String getNegotiatedProtocol()

  - ### setNegotiatedProtocol

    public void setNegotiatedProtocol(String negotiatedProtocol)

  - ### getSniHostName

    public String getSniHostName()
    Returns:
      the sniHostName

  - ### setSniHostName

    public void setSniHostName(String sniHostName)
    Parameters:
      `sniHostName` - the SNI host name to set

  - ### setReadTimeout

    public void setReadTimeout(long readTimeout)
    Set the timeout for reading. Values of zero or less will be changed to -1.
    Parameters:
      `readTimeout` - The timeout in milliseconds. A value of -1 indicates an infinite timeout.

  - ### getReadTimeout

    public long getReadTimeout()

  - ### setWriteTimeout

    public void setWriteTimeout(long writeTimeout)
    Set the timeout for writing. Values of zero or less will be changed to -1.
    Parameters:
      `writeTimeout` - The timeout in milliseconds. A value of zero or less indicates an infinite timeout.

  - ### getWriteTimeout

    public long getWriteTimeout()

  - ### setKeepAliveLeft

    public void setKeepAliveLeft(int keepAliveLeft)

  - ### decrementKeepAlive

    public int decrementKeepAlive()

  - ### getRemoteHost

    public String getRemoteHost()

  - ### populateRemoteHost

    protected abstract void populateRemoteHost()

  - ### getRemoteAddr

    public String getRemoteAddr()

  - ### populateRemoteAddr

    protected abstract void populateRemoteAddr()

  - ### getRemotePort

    public int getRemotePort()

  - ### populateRemotePort

    protected abstract void populateRemotePort()

  - ### getLocalName

    public String getLocalName()

  - ### populateLocalName

    protected abstract void populateLocalName()

  - ### getLocalAddr

    public String getLocalAddr()

  - ### populateLocalAddr

    protected abstract void populateLocalAddr()

  - ### getLocalPort

    public int getLocalPort()

  - ### populateLocalPort

    protected abstract void populateLocalPort()

  - ### getSocketBufferHandler

    public SocketBufferHandler getSocketBufferHandler()

  - ### hasDataToRead

    public boolean hasDataToRead()

  - ### hasDataToWrite

    public boolean hasDataToWrite()

  - ### isReadyForWrite

    public boolean isReadyForWrite()
    Checks to see if there are any writes pending and if there are calls `registerWriteInterest()` to trigger a callback once the pending writes have completed.

    Note: Once this method has returned `false` it MUST NOT be called again until the pending write has completed and the callback has been fired. TODO: Modify `registerWriteInterest()` so the above restriction is enforced there rather than relying on the caller.

    Returns:
      `true` if no writes are pending and data can be written otherwise `false`

  - ### canWrite

    public boolean canWrite()

  - ### toString

    public String toString()
    Overridden for debug purposes. No guarantees are made about the format of this message which may vary significantly between point releases.

    Overrides:
      `toString` in class `Object`

  - ### read

    public abstract int read(boolean block, byte[] b, int off, int len) throws IOException
    Throws:
      `IOException`

  - ### read

    public abstract int read(boolean block, ByteBuffer to) throws IOException
    Throws:
      `IOException`

  - ### isReadyForRead

    public abstract boolean isReadyForRead() throws IOException
    Throws:
      `IOException`

  - ### setAppReadBufHandler

    public abstract void setAppReadBufHandler(ApplicationBufferHandler handler)

  - ### populateReadBuffer

    protected int populateReadBuffer(byte[] b, int off, int len)

  - ### populateReadBuffer

    protected int populateReadBuffer(ByteBuffer to)

  - ### unRead

    public void unRead(ByteBuffer returnedInput)
    Return input that has been read to the input buffer for re-reading by the correct component. There are times when a component may read more data than it needs before it passes control to another component. One example of this is during HTTP upgrade. If an (arguably misbehaving client) sends data associated with the upgraded protocol before the HTTP upgrade completes, the HTTP handler may read it. This method provides a way for that data to be returned so it can be processed by the correct component.
    Parameters:
      `returnedInput` - The input to return to the input buffer.

  - ### close

    public void close()
    Close the socket wrapper.

  - ### doClose

    protected abstract void doClose()
    Perform the actual close. The closed atomic boolean guarantees this will be called only once per wrapper.

  - ### isClosed

    public boolean isClosed()
    Returns:
      true if the wrapper has been closed

  - ### write

    public final void write(boolean block, byte[] buf, int off, int len) throws IOException
    Writes the provided data to the socket write buffer. If the socket write buffer fills during the write, the content of the socket write buffer is written to the network and this method starts to fill the socket write buffer again. Depending on the size of the data to write, there may be multiple writes to the network.

    Non-blocking writes must return immediately and the byte array holding the data to be written must be immediately available for re-use. It may not be possible to write sufficient data to the network to allow this to happen. In this case data that cannot be written to the network and cannot be held by the socket buffer is stored in the non-blocking write buffer.

    Note: There is an implementation assumption that, before switching from non-blocking writes to blocking writes, any data remaining in the non-blocking write buffer will have been written to the network.

    Parameters:
      `block` - `true` if a blocking write should be used, otherwise a non-blocking write will be used
      `buf` - The byte array containing the data to be written
      `off` - The offset within the byte array of the data to be written
      `len` - The length of the data to be written
    Throws:
      `IOException` - If an IO error occurs during the write

  - ### write

    public final void write(boolean block, ByteBuffer from) throws IOException
    Writes the provided data to the socket write buffer. If the socket write buffer fills during the write, the content of the socket write buffer is written to the network and this method starts to fill the socket write buffer again. Depending on the size of the data to write, there may be multiple writes to the network.

    Non-blocking writes must return immediately and the ByteBuffer holding the data to be written must be immediately available for re-use. It may not be possible to write sufficient data to the network to allow this to happen. In this case data that cannot be written to the network and cannot be held by the socket buffer is stored in the non-blocking write buffer.

    Note: There is an implementation assumption that, before switching from non-blocking writes to blocking writes, any data remaining in the non-blocking write buffer will have been written to the network.

    Parameters:
      `block` - `true` if a blocking write should be used, otherwise a non-blocking write will be used
      `from` - The ByteBuffer containing the data to be written
    Throws:
      `IOException` - If an IO error occurs during the write

  - ### writeBlocking

    protected void writeBlocking(byte[] buf, int off, int len) throws IOException
    Writes the provided data to the socket write buffer. If the socket write buffer fills during the write, the content of the socket write buffer is written to the network using a blocking write. Once that blocking write is complete, this method starts to fill the socket write buffer again. Depending on the size of the data to write, there may be multiple writes to the network. On completion of this method there will always be space remaining in the socket write buffer.
    Parameters:
      `buf` - The byte array containing the data to be written
      `off` - The offset within the byte array of the data to be written
      `len` - The length of the data to be written
    Throws:
      `IOException` - If an IO error occurs during the write

  - ### writeBlocking

    protected void writeBlocking(ByteBuffer from) throws IOException
    Writes the provided data to the socket write buffer. If the socket write buffer fills during the write, the content of the socket write buffer is written to the network using a blocking write. Once that blocking write is complete, this method starts to fill the socket write buffer again. Depending on the size of the data to write, there may be multiple writes to the network. On completion of this method there will always be space remaining in the socket write buffer.
    Parameters:
      `from` - The ByteBuffer containing the data to be written
    Throws:
      `IOException` - If an IO error occurs during the write

  - ### writeNonBlocking

    protected void writeNonBlocking(byte[] buf, int off, int len) throws IOException
    Transfers the data to the socket write buffer (writing that data to the socket if the buffer fills up using a non-blocking write) until either all the data has been transferred and space remains in the socket write buffer or a non-blocking write leaves data in the socket write buffer. After an incomplete write, any data remaining to be transferred to the socket write buffer will be copied to the socket write buffer. If the remaining data is too big for the socket write buffer, the socket write buffer will be filled and the additional data written to the non-blocking write buffer.
    Parameters:
      `buf` - The byte array containing the data to be written
      `off` - The offset within the byte array of the data to be written
      `len` - The length of the data to be written
    Throws:
      `IOException` - If an IO error occurs during the write

  - ### writeNonBlocking

    protected void writeNonBlocking(ByteBuffer from) throws IOException
    Transfers the data to the socket write buffer (writing that data to the socket if the buffer fills up using a non-blocking write) until either all the data has been transferred and space remains in the socket write buffer or a non-blocking write leaves data in the socket write buffer. After an incomplete write, any data remaining to be transferred to the socket write buffer will be copied to the socket write buffer. If the remaining data is too big for the socket write buffer, the socket write buffer will be filled and the additional data written to the non-blocking write buffer.
    Parameters:
      `from` - The ByteBuffer containing the data to be written
    Throws:
      `IOException` - If an IO error occurs during the write

  - ### writeNonBlockingInternal

    protected void writeNonBlockingInternal(ByteBuffer from) throws IOException
    Separate method so it can be re-used by the socket write buffer to write data to the network
    Parameters:
      `from` - The ByteBuffer containing the data to be written
    Throws:
      `IOException` - If an IO error occurs during the write

  - ### flush

    public boolean flush(boolean block) throws IOException
    Writes as much data as possible from any that remains in the buffers.
    Parameters:
      `block` - `true` if a blocking write should be used, otherwise a non-blocking write will be used
    Returns:
      `true` if data remains to be flushed after this method completes, otherwise `false`. In blocking mode therefore, the return value should always be `false`
    Throws:
      `IOException` - If an IO error occurs during the write

  - ### flushBlocking

    protected void flushBlocking() throws IOException
    Writes all remaining data from the buffers and blocks until the write is complete.
    Throws:
      `IOException` - If an IO error occurs during the write

  - ### flushNonBlocking

    protected abstract boolean flushNonBlocking() throws IOException
    Writes as much data as possible from any that remains in the buffers.
    Returns:
      `true` if data remains to be flushed after this method completes, otherwise `false`.
    Throws:
      `IOException` - If an IO error occurs during the write

  - ### doWrite

    protected void doWrite(boolean block) throws IOException
    Write the contents of the socketWriteBuffer to the socket. For blocking writes either then entire contents of the buffer will be written or an IOException will be thrown. Partial blocking writes will not occur.
    Parameters:
      `block` - Should the write be blocking or not?
    Throws:
      `IOException` - If an I/O error such as a timeout occurs during the write

  - ### doWrite

    protected abstract void doWrite(boolean block, ByteBuffer from) throws IOException
    Write the contents of the ByteBuffer to the socket. For blocking writes either then entire contents of the buffer will be written or an IOException will be thrown. Partial blocking writes will not occur.
    Parameters:
      `block` - Should the write be blocking or not?
      `from` - the ByteBuffer containing the data to be written
    Throws:
      `IOException` - If an I/O error such as a timeout occurs during the write

  - ### processSocket

    public void processSocket(SocketEvent socketStatus, boolean dispatch)

  - ### registerReadInterest

    public abstract void registerReadInterest()

  - ### registerWriteInterest

    public abstract void registerWriteInterest()

  - ### createSendfileData

    public abstract SendfileDataBase createSendfileData(String filename, long pos, long length)

  - ### processSendfile

    public abstract SendfileState processSendfile(SendfileDataBase sendfileData)
    Starts the sendfile process. It is expected that if the sendfile process does not complete during this call and does not report an error, that the caller will not add the socket to the poller (or equivalent). That is the responsibility of this method.
    Parameters:
      `sendfileData` - Data representing the file to send
    Returns:
      The state of the sendfile process after the first write.

  - ### doClientAuth

    public abstract void doClientAuth(SSLSupport sslSupport) throws IOException
    Require the client to perform CLIENT-CERT authentication if it hasn't already done so.
    Parameters:
      `sslSupport` - The SSL/TLS support instance currently being used by the connection that may need updating after the client authentication
    Throws:
      `IOException` - If authentication is required then there will be I/O with the client and this exception will be thrown if that goes wrong

  - ### getSslSupport

    public abstract SSLSupport getSslSupport()
    Obtain an SSLSupport instance for this socket.
    Returns:
      An SSLSupport instance for this socket.

  - ### hasAsyncIO

    public boolean hasAsyncIO()
    Allows using NIO2 style read/write.
    Returns:
      `true` if the connector has the capability enabled

  - ### needSemaphores

    public boolean needSemaphores()
    Allows indicating if the connector needs semaphores.
    Returns:
      This default implementation always returns `false`

  - ### hasPerOperationTimeout

    public boolean hasPerOperationTimeout()
    Allows indicating if the connector supports per operation timeout.
    Returns:
      This default implementation always returns `false`

  - ### isReadPending

    public boolean isReadPending()
    Allows checking if an asynchronous read operation is currently pending.
    Returns:
      `true` if the endpoint supports asynchronous IO and a read operation is being processed asynchronously

  - ### isWritePending

    public boolean isWritePending()
    Allows checking if an asynchronous write operation is currently pending.
    Returns:
      `true` if the endpoint supports asynchronous IO and a write operation is being processed asynchronously

  - ### read

    public final <A> SocketWrapperBase.CompletionState read(long timeout, TimeUnit unit, A attachment, CompletionHandler<Long, ? super A> handler, ByteBuffer... dsts)
    Scatter read. The completion handler will be called once some data has been read or an error occurred. The default NIO2 behavior is used: the completion handler will be called as soon as some data has been read, even if the read has completed inline.
    Type Parameters:
      `A` - The attachment type
    Parameters:
      `timeout` - timeout duration for the read
      `unit` - units for the timeout duration
      `attachment` - an object to attach to the I/O operation that will be used when calling the completion handler
      `handler` - to call when the IO is complete
      `dsts` - buffers
    Returns:
      the completion state (done, done inline, or still pending)

  - ### read

    public final <A> SocketWrapperBase.CompletionState read(SocketWrapperBase.BlockingMode block, long timeout, TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, CompletionHandler<Long, ? super A> handler, ByteBuffer... dsts)
    Scatter read. The completion handler will be called once some data has been read or an error occurred. If a CompletionCheck object has been provided, the completion handler will only be called if the callHandler method returned true. If no CompletionCheck object has been provided, the default NIO2 behavior is used: the completion handler will be called as soon as some data has been read, even if the read has completed inline.
    Type Parameters:
      `A` - The attachment type
    Parameters:
      `block` - is the blocking mode that will be used for this operation
      `timeout` - timeout duration for the read
      `unit` - units for the timeout duration
      `attachment` - an object to attach to the I/O operation that will be used when calling the completion handler
      `check` - for the IO operation completion
      `handler` - to call when the IO is complete
      `dsts` - buffers
    Returns:
      the completion state (done, done inline, or still pending)

  - ### read

    public final <A> SocketWrapperBase.CompletionState read(ByteBuffer[] dsts, int offset, int length, SocketWrapperBase.BlockingMode block, long timeout, TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, CompletionHandler<Long, ? super A> handler)
    Scatter read. The completion handler will be called once some data has been read or an error occurred. If a CompletionCheck object has been provided, the completion handler will only be called if the callHandler method returned true. If no CompletionCheck object has been provided, the default NIO2 behavior is used: the completion handler will be called as soon as some data has been read, even if the read has completed inline.
    Type Parameters:
      `A` - The attachment type
    Parameters:
      `dsts` - buffers
      `offset` - in the buffer array
      `length` - in the buffer array
      `block` - is the blocking mode that will be used for this operation
      `timeout` - timeout duration for the read
      `unit` - units for the timeout duration
      `attachment` - an object to attach to the I/O operation that will be used when calling the completion handler
      `check` - for the IO operation completion
      `handler` - to call when the IO is complete
    Returns:
      the completion state (done, done inline, or still pending)

  - ### write

    public final <A> SocketWrapperBase.CompletionState write(long timeout, TimeUnit unit, A attachment, CompletionHandler<Long, ? super A> handler, ByteBuffer... srcs)
    Gather write. The completion handler will be called once some data has been written or an error occurred. The default NIO2 behavior is used: the completion handler will be called, even if the write is incomplete and data remains in the buffers, or if the write completed inline.
    Type Parameters:
      `A` - The attachment type
    Parameters:
      `timeout` - timeout duration for the write
      `unit` - units for the timeout duration
      `attachment` - an object to attach to the I/O operation that will be used when calling the completion handler
      `handler` - to call when the IO is complete
      `srcs` - buffers
    Returns:
      the completion state (done, done inline, or still pending)

  - ### write

    public final <A> SocketWrapperBase.CompletionState write(SocketWrapperBase.BlockingMode block, long timeout, TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, CompletionHandler<Long, ? super A> handler, ByteBuffer... srcs)
    Gather write. The completion handler will be called once some data has been written or an error occurred. If a CompletionCheck object has been provided, the completion handler will only be called if the callHandler method returned true. If no CompletionCheck object has been provided, the default NIO2 behavior is used: the completion handler will be called, even if the write is incomplete and data remains in the buffers, or if the write completed inline.
    Type Parameters:
      `A` - The attachment type
    Parameters:
      `block` - is the blocking mode that will be used for this operation
      `timeout` - timeout duration for the write
      `unit` - units for the timeout duration
      `attachment` - an object to attach to the I/O operation that will be used when calling the completion handler
      `check` - for the IO operation completion
      `handler` - to call when the IO is complete
      `srcs` - buffers
    Returns:
      the completion state (done, done inline, or still pending)

  - ### write

    public final <A> SocketWrapperBase.CompletionState write(ByteBuffer[] srcs, int offset, int length, SocketWrapperBase.BlockingMode block, long timeout, TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, CompletionHandler<Long, ? super A> handler)
    Gather write. The completion handler will be called once some data has been written or an error occurred. If a CompletionCheck object has been provided, the completion handler will only be called if the callHandler method returned true. If no CompletionCheck object has been provided, the default NIO2 behavior is used: the completion handler will be called, even if the write is incomplete and data remains in the buffers, or if the write completed inline.
    Type Parameters:
      `A` - The attachment type
    Parameters:
      `srcs` - buffers
      `offset` - in the buffer array
      `length` - in the buffer array
      `block` - is the blocking mode that will be used for this operation
      `timeout` - timeout duration for the write
      `unit` - units for the timeout duration
      `attachment` - an object to attach to the I/O operation that will be used when calling the completion handler
      `check` - for the IO operation completion
      `handler` - to call when the IO is complete
    Returns:
      the completion state (done, done inline, or still pending)

  - ### vectoredOperation

    protected final <A> SocketWrapperBase.CompletionState vectoredOperation(boolean read, ByteBuffer[] buffers, int offset, int length, SocketWrapperBase.BlockingMode block, long timeout, TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, CompletionHandler<Long, ? super A> handler)
    Vectored operation. The completion handler will be called once the operation is complete or an error occurred. If a CompletionCheck object has been provided, the completion handler will only be called if the callHandler method returned true. If no CompletionCheck object has been provided, the default NIO2 behavior is used: the completion handler will be called, even if the operation is incomplete, or if the operation completed inline.
    Type Parameters:
      `A` - The attachment type
    Parameters:
      `read` - true if the operation is a read, false if it is a write
      `buffers` - buffers
      `offset` - in the buffer array
      `length` - in the buffer array
      `block` - is the blocking mode that will be used for this operation
      `timeout` - timeout duration for the write
      `unit` - units for the timeout duration
      `attachment` - an object to attach to the I/O operation that will be used when calling the completion handler
      `check` - for the IO operation completion
      `handler` - to call when the IO is complete
    Returns:
      the completion state (done, done inline, or still pending)

  - ### newOperationState

    protected abstract <A> SocketWrapperBase<E>.OperationState<A> newOperationState(boolean read, ByteBuffer[] buffers, int offset, int length, SocketWrapperBase.BlockingMode block, long timeout, TimeUnit unit, A attachment, SocketWrapperBase.CompletionCheck check, CompletionHandler<Long, ? super A> handler, Semaphore semaphore, SocketWrapperBase<E>.VectoredIOCompletionHandler<A> completion)

  - ### transfer

    protected static int transfer(byte[] from, int offset, int length, ByteBuffer to)

  - ### transfer

    protected static int transfer(ByteBuffer from, ByteBuffer to)

  - ### buffersArrayHasRemaining

    protected static boolean buffersArrayHasRemaining(ByteBuffer[] buffers, int offset, int length)

  - ### getServletConnection

    public ServletConnection getServletConnection(String protocol, String protocolConnectionId)