oracle.ifs.beans.parsers
Class ParserInputStream

java.lang.Object

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  +--java.io.InputStream

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        +--oracle.ifs.beans.parsers.ParserInputStream

public class ParserInputStream

extends java.io.InputStream

A ParserInputStream is an InputStream that supports buffering of input such that the buffer can be reset to the beginning, allowing bytes to be re-read.

As such, a ParserInputStream can be used whenever the input data needs to be re-read. For example, it is used for pre-parsing a file to determine the nature of its content, before passing it to the appropriate parser for actual parsing.

It can operate in buffering or non-buffering mode. When in buffering mode, it buffers the input, extending the size of the buffer as required.

The ParserInputStream can be reset to allow re-reading of the input data. When reset and put in non-buffering mode, it consumes the bytes in the buffer to service read requests, until it reaches the end of the buffered data, at which point it will start reading from the underlying InputStream. When reset and operating in buffering mode, it consumes the bytes in the buffer to service read requests, until it reaches the end of the buffered data, at which point it will read more data into the buffer and services read requests from the contents of the buffer.

A ParserInputStream can only be reset if already in buffering mode.

Constructor Summary

ParserInputStream(java.io.InputStream is)
Constructs a ParserInputStream from an InputStream.

Method Summary

boolean	getBufferingMode() Gets the buffering mode indicating whether the stream is currently in buffering mode or non-buffering mode.
int	read() Reads the next byte of data from this input stream.
int	read(byte[] b) Reads up to b.length bytes of data from this input stream into an array of bytes.
int	read(byte[] b, int offset, int len) Reads up to len bytes of data from this input stream into an array of bytes at the position specified by offset.
void	resetStream(boolean bufferingMode) Resets the stream such that it can be re-read.
void	setBufferingMode(boolean mode) Set the stream into the desired mode.

Constructor Detail

ParserInputStream

public ParserInputStream(java.io.InputStream is)

Constructs a ParserInputStream from an InputStream.

Parameters:

is - the InputStream

Method Detail

read

public int read()
         throws java.io.IOException

Reads the next byte of data from this input stream.

The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned.

Overrides:

read in class java.io.InputStream

Returns:

the int, or -1 when the end of the stream has been reached

Throws:

java.io.IOException - if an I/O error occurs

read

public int read(byte[] b)
         throws java.io.IOException

Reads up to b.length bytes of data from this input stream into an array of bytes.

Overrides:

read in class java.io.InputStream

Parameters:

b - the buffer into which the data is read

Returns:

the total number of bytes read into the buffer, or -1 when the end of the stream has been reached

Throws:

java.io.IOException - if an I/O error occurs

read

public int read(byte[] b,
                int offset,
                int len)
         throws java.io.IOException

Reads up to len bytes of data from this input stream into an array of bytes at the position specified by offset.

Overrides:

read in class java.io.InputStream

Parameters:

b - the buffer into which the data is read

offset - the start offset of the data

len - the maximum number of bytes read

Returns:

the total number of bytes read into the buffer, or -1 when the end of the stream has been reached

Throws:

java.io.IOException - if an I/O error occurs

setBufferingMode

public void setBufferingMode(boolean mode)

Set the stream into the desired mode.

If true is passed in, the stream is put into buffering mode, so that it can be reset subsequently to re-read the stream. If false is passed in, the stream is put into non-buffering mode, and it cannot be subsequently reset.

Parameters:

mode - can be true or false, indicating whether the stream should be put into buffering mode or non-buffering mode mode

getBufferingMode

public boolean getBufferingMode()

Gets the buffering mode indicating whether the stream is currently in buffering mode or non-buffering mode.

Returns:

true or false, indicating whether the stream is currently in buffering or non-buffering mode

resetStream

public void resetStream(boolean bufferingMode)
                 throws IfsException

Resets the stream such that it can be re-read.

The stream can continue to operate in buffering mode after the reset, or it can be set to non-buffering mode following reset. The buffering mode should be set according to whether the stream will need to be re-read. A stream that is not in buffering mode cannot be reset.

Parameters:

bufferingMode - determines whether the stream should continue in buffering mode after being reset

Throws:

IfsException - if attempting to reset a stream that is not in buffering mode