Class TransportCursor

java.lang.Object
org.simpleframework.transport.TransportCursor
All Implemented Interfaces:
Cursor
public class TransportCursor extends Object implements Cursor
The TransportCursor object represents a cursor that can read and buffer data from an underlying transport. If the number of bytes read from the cursor is more than required for the HTTP request then those bytes can be pushed back in to the cursor using the reset method. This will only allow the last read to be reset within the cursor safely.
Author:
Niall Gallagher
See Also:

  • Constructor Summary

    Constructors
    Constructor
    Description
    TransportCursor(Transport transport)
    Constructor for the TransportCursor object.
    TransportCursor(Transport transport, int size)
    Constructor for the TransportCursor object.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    isOpen()
    Determines whether the cursor is still open.
    boolean
    isReady()
    Determines whether the cursor is ready for reading.
    void
    push(byte[] data)
    Pushes the provided data on to the cursor.
    void
    push(byte[] data, int off, int len)
    Pushes the provided data on to the cursor.
    int
    read(byte[] data)
    Reads a block of bytes from the underlying stream.
    int
    read(byte[] data, int off, int len)
    Reads a block of bytes from the underlying stream.
    int
    ready()
    Provides the number of bytes that can be read from the stream without blocking.
    int
    reset(int size)
    Moves the cursor backward within the stream.

    Methods inherited from class Object

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

  • Constructor Details

    • TransportCursor

      public TransportCursor(Transport transport)
      Constructor for the TransportCursor object. This requires a transport to read the bytes from. By default this will create a buffer of of the specified size to read the input in to which enabled bytes to be buffered internally.
      Parameters:
      transport - this is the underlying transport to use

    • TransportCursor

      public TransportCursor(Transport transport, int size)
      Constructor for the TransportCursor object. This requires a transport to read the bytes from. By default this will create a buffer of of the specified size to read the input in to which enabled bytes to be buffered internally.
      Parameters:
      transport - this is the underlying transport to use
      size - this is the size of the internal buffer to use

  • Method Details

    • isOpen

      public boolean isOpen() throws IOException
      Determines whether the cursor is still open. The cursor is considered open if there are still bytes to read. If there is still bytes buffered and the underlying transport is closed then the cursor is still considered open.
      Specified by:
      isOpen in interface Cursor
      Returns:
      true if there is nothing more to be read from this
      Throws:
      IOException

    • isReady

      public boolean isReady() throws IOException
      Determines whether the cursor is ready for reading. When the cursor is ready then it guarantees that some amount of bytes can be read from the underlying stream without blocking.
      Specified by:
      isReady in interface Cursor
      Returns:
      true if some data can be read without blocking
      Throws:
      IOException

    • ready

      public int ready() throws IOException
      Provides the number of bytes that can be read from the stream without blocking. This is typically the number of buffered or available bytes within the stream. When this reaches zero then the cursor may perform a blocking read.
      Specified by:
      ready in interface Cursor
      Returns:
      the number of bytes that can be read without blocking
      Throws:
      IOException

    • read

      public int read(byte[] data) throws IOException
      Reads a block of bytes from the underlying stream. This will read up to the requested number of bytes from the underlying stream. If there are no ready bytes on the stream this can return zero, representing the fact that nothing was read.
      Specified by:
      read in interface Cursor
      Parameters:
      data - this is the array to read the bytes in to
      Returns:
      this returns the number of bytes read from the stream
      Throws:
      IOException

    • read

      public int read(byte[] data, int off, int len) throws IOException
      Reads a block of bytes from the underlying stream. This will read up to the requested number of bytes from the underlying stream. If there are no ready bytes on the stream this can return zero, representing the fact that nothing was read.
      Specified by:
      read in interface Cursor
      Parameters:
      data - this is the array to read the bytes in to
      off - this is the offset to begin writing the bytes to
      len - this is the number of bytes that are requested
      Returns:
      this returns the number of bytes read from the stream
      Throws:
      IOException

    • push

      public void push(byte[] data) throws IOException
      Pushes the provided data on to the cursor. Data pushed on to the cursor will be the next data read from the cursor. This complements the reset method which will reset the cursors position on a stream. Allowing data to be pushed on to the cursor allows more flexibility.
      Specified by:
      push in interface Cursor
      Parameters:
      data - this is the data to be pushed on to the cursor
      Throws:
      IOException

    • push

      public void push(byte[] data, int off, int len) throws IOException
      Pushes the provided data on to the cursor. Data pushed on to the cursor will be the next data read from the cursor. This complements the reset method which will reset the cursors position on a stream. Allowing data to be pushed on to the cursor allows more flexibility.
      Specified by:
      push in interface Cursor
      Parameters:
      data - this is the data to be pushed on to the cursor
      off - this is the offset to begin reading the bytes
      len - this is the number of bytes that are to be used
      Throws:
      IOException

    • reset

      public int reset(int size) throws IOException
      Moves the cursor backward within the stream. This ensures that any bytes read from the last read can be pushed back in to the stream so that they can be read again. This will throw an exception if the reset can not be performed.
      Specified by:
      reset in interface Cursor
      Parameters:
      size - this is the number of bytes to reset back
      Returns:
      this is the number of bytes that have been reset
      Throws:
      IOException