com.devexperts.io

Class BufferedInputPart

java.lang.Object

java.io.InputStream

com.devexperts.io.BufferedInput

com.devexperts.io.BufferedInputPart

All Implemented Interfaces:

Closeable, DataInput, ObjectInput, AutoCloseable

public final class BufferedInputPart
extends BufferedInput

A size-delimited part of BufferedInput for parsing of size-tagged packets. The totalPosition of the BufferedInputPart is the same as the totalPosition of the underlying BufferedInput, but the number of bytes available in the BufferedInputPart is limited by the length specified in its constructor or in setInput method.

Reading from this BufferedInputPart does not automatically advance position in the underlying input, but it does not stay fixed either. The position of the underlying BufferedInput is advanced at unspecified times. Use syncInputPosition method to advance it to the current position of this BufferedInputPart when needed.

Field Summary

Fields inherited from class com.devexperts.io.BufferedInput

buffer, EMPTY_BYTE_ARRAY, limit, markPosition, position, totalPositionBase

Constructor Summary

Constructors

Constructor and Description
BufferedInputPart() Creates BufferedInputPart object that needs to be bound to a particular underlying input by setInput method before use.
BufferedInputPart(BufferedInput in, long length) Creates BufferedInputPart object that is bound the part of the specified input and is limited by the particular length.

Method Summary

Modifier and Type	Method and Description
int	available() Returns the number of bytes that can be read without blocking.
protected void	checkEncapsulatedLength(long length, long min, long max) Validate encapsulated content length according to specified bounds and stream limits.
void	close() Unbinds this BufferedInputPart object from the underlying input with resetInput method.
boolean	hasAvailable() Checks if more bytes can be read from this input.
boolean	hasAvailable(int bytes) Checks if the specified number of bytes can be read from this input.
int	read(byte[] b, int off, int len)
protected int	readData() This method is invoked when input methods need more bytes to read data.
void	resetInput() Unbinds this BufferedInputPart object from the underlying input.
void	rewind(long n) Rewinds specified number of bytes.
void	setInput(BufferedInput in, long length) Binds this BufferedInputPart object to the part of the specified input with a limit by the particular length.
long	skip(long n)
void	syncInputPosition() Updates underlying BufferedInput position so that it corresponds to the position that this BufferedInputPart was read to.

Methods inherited from class com.devexperts.io.BufferedInput

checkEOB, checkRewind, mark, mark, mark, markSupported, needData, read, read, readBoolean, readByte, readByteArray, readChar, readCompactInt, readCompactLong, readDouble, readFloat, readFully, readFully, readInt, readLine, readLong, readMarshalled, readMarshalled, readObject, readObject, readObject, readShort, readToByteBuffer, readToDataOutput, readToOutputStream, readUnsignedByte, readUnsignedShort, readUTF, readUTFBody, readUTFChar, readUTFString, reset, seek, skipBytes, throwEOFException, totalPosition, unmark

Methods inherited from class java.lang.Object

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

Constructor Detail

BufferedInputPart

public BufferedInputPart()

Creates BufferedInputPart object that needs to be bound to a particular underlying input by setInput method before use.

BufferedInputPart

public BufferedInputPart(BufferedInput in,
                         long length)

Creates BufferedInputPart object that is bound the part of the specified input and is limited by the particular length. See setInput method for all preconditions.

Parameters:

in - the underlying input.

length - the length limit.

Throws:

NullPointerException - if in is null.

IllegalStateException - if the underlying input is not marked properly.

Method Detail

setInput

public void setInput(BufferedInput in,
                     long length)

Binds this BufferedInputPart object to the part of the specified input with a limit by the particular length. This method can be called multiple times to reuse this instance by binding it differently. The underlying BufferedInput this method was previously bound to is ignored by this method for a predictable reuse behavior regardless of how the previous use of this instance has terminated. The state of this BufferedInputPart is completely reset as if it was created from scratch.

The underlying BufferedInput has to be marked before invocation of this method.

The behavior of this BufferedInputPart is undefined if the underlying BufferedInput is changed in any way directly by reading from it or otherwise changing its position or mark before this BufferedInputPart is disposed of or unbound.

Parameters:

in - the underlying input.

length - the length limit.

Throws:

NullPointerException - if in is null.

IllegalStateException - if the underlying input is not marked.

syncInputPosition

public void syncInputPosition()

Updates underlying BufferedInput position so that it corresponds to the position that this BufferedInputPart was read to. Unlike resetInput method, this BufferedInputPart continues to be bound.

Throws:

NullPointerException - if this BufferedInputPart is not bound.

resetInput

public void resetInput()

Unbinds this BufferedInputPart object from the underlying input. This method does nothing if this instance is not currently bound. This method does not synchronize the underlying BufferedInput position with syncInputPosition method.

close

public void close()

Unbinds this BufferedInputPart object from the underlying input with resetInput method. The underlying BufferedInput is not closed.

Specified by:

close in interface Closeable

Specified by:

close in interface ObjectInput

Specified by:

close in interface AutoCloseable

Overrides:

close in class InputStream

hasAvailable

public boolean hasAvailable()
                     throws IOException

Checks if more bytes can be read from this input. This is a faster-working shortcut for available() > 0 check. This method returns false when this object is not bound.

Overrides:

hasAvailable in class BufferedInput

Returns:

true if more bytes can be read from this input.

Throws:

IOException - if an I/O error occurs.

hasAvailable

public boolean hasAvailable(int bytes)
                     throws IOException

Checks if the specified number of bytes can be read from this input. This is a faster-working shortcut for available() >= bytes check. This method returns bytes <= 0 when this object is not bound.

Overrides:

hasAvailable in class BufferedInput

Parameters:

bytes - the number of bytes.

Returns:

true if the specified number of bytes can be read from this input.

Throws:

NullPointerException - if this object is not bound with setInput.

IOException - if an I/O error occurs.

available

public int available()
              throws IOException

Returns the number of bytes that can be read without blocking. The resulting number will not exceed length specified when binding this object with setInput method. This method returns 0 when this object is not bound.

Specified by:

available in interface ObjectInput

Overrides:

available in class BufferedInput

Returns:

the number of available bytes.

Throws:

IOException - If an I/O error has occurred.

read

public int read(byte[] b,
                int off,
                int len)
         throws IOException

Specified by:

read in interface ObjectInput

Overrides:

read in class BufferedInput

Throws:

IOException

skip

public long skip(long n)
          throws IOException

Specified by:

skip in interface ObjectInput

Overrides:

skip in class BufferedInput

Throws:

IOException

rewind

public void rewind(long n)

Rewinds specified number of bytes. The input cannot be rewound past the marked position.

Specified by:

rewind in class BufferedInput

Parameters:

n - the number of bytes to rewind

readData

protected int readData()
                throws IOException

This method is invoked when input methods need more bytes to read data. This method shall make an attempt to read some bytes into the buffer. This method returns number of bytes actually read or value -1 if no bytes can be read because the end of the stream has been reached. This method may block if needed. This method is allowed to update buffer, position, limit and totalPositionBase fields as needed.

This method shall never throw an EOFException.

Specified by:

readData in class BufferedInput

Returns:

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached

Throws:

IOException - if an I/O error occurs

checkEncapsulatedLength

protected void checkEncapsulatedLength(long length,
                                       long min,
                                       long max)
                                throws IOException

Validate encapsulated content length according to specified bounds and stream limits.

Data retrieval methods getting variable amount of data can invoke this method to check an upper bound of available data for validation.

Overrides:

checkEncapsulatedLength in class BufferedInput

Parameters:

length - encapsulated length value to be checked

min - minimal theoretically valid length value

max - maximal theoretically valid length value

Throws:

IOException - if length < min || length > max or length bytes definitely cannot be retrieved