info.bioinfweb.commons.io

Class LimitedInputStream

java.lang.Object

java.io.InputStream

info.bioinfweb.commons.io.LimitedInputStream

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

public class LimitedInputStream
extends java.io.InputStream

Guarantees that no more bytes as specified are read from the decorated reader. It is though possible, that the decorated reader reads beyond the read limit from its underlying reader (e.g. if a BufferedReader is decorated).

The focus of this class is to make sure that not more characters than specified can be read from the underlying reader. It can e.g. be used to ensure that reading beyond the read ahead limit of a call of mark(int) is not possible.

Since:

2.0.0

Author:

Ben Stöver

See Also:

LimitedReader

Constructor Summary

Constructors

Constructor and Description
LimitedInputStream(java.io.InputStream decoratedStream, long limit) Creates a new instance of this class.

Method Summary

Modifier and Type	Method and Description
int	available()
long	availableCharacters() The number of bytes available, before the specified maximum number will have been read from the decorated input stream.
void	close() Closes the decorated input stream, if that is currently allowed.
long	getLimit() Returns the maximum number of bytes that will be read from the decorated stream.
boolean	isAllowClose() Determines whether closing this input stream shall currently be prevented.
boolean	isLimitReached() Checks whether the specified maximum number of bytes has been read from the decorated input stream.
void	mark(int readAheadLimit)
boolean	markSupported()
int	read() Returns the next byte from the decorated stream or -1 if either the end of the decorated stream or the limit specified to this stream have been reached.
void	reset()
void	setAllowClose(boolean allowClose) Allows to specify whether closing this input stream shall currently be prevented.
long	skip(long n)

Methods inherited from class java.io.InputStream

read, read

Methods inherited from class java.lang.Object

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

Constructor Detail

LimitedInputStream

public LimitedInputStream(java.io.InputStream decoratedStream,
                          long limit)

Creates a new instance of this class.

Parameters:

decoratedStream - the input stream to be decorated

limit - the maximum number of bytes that shall be read from the decorated input stream

Method Detail

getLimit

public long getLimit()

Returns the maximum number of bytes that will be read from the decorated stream.

Returns:

the maximum number of bytes to be read from the decorated stream

availableCharacters

public long availableCharacters()

The number of bytes available, before the specified maximum number will have been read from the decorated input stream. Note that the end of the stream (e.g. end of file) may possibly be reached before the specified limit, which is not reflected by the return value of this method.

Returns:

the number of bytes that could be read before the limit of this input stream is reached

isLimitReached

public boolean isLimitReached()

Checks whether the specified maximum number of bytes has been read from the decorated input stream. Note that this method will return true, if the maximum number of bytes has not yet been read, even if the end of the stream was already reached. In such cases it can be used to determine whether the limit or the real end of the stream have been reached.

Returns:

true if the maximum number of bytes was read, false if the limit is not yet reached

isAllowClose

public boolean isAllowClose()

Determines whether closing this input stream shall currently be prevented. Calls of close() will throw an ClosingNotAllowedException in such cases.

Returns:

true, if closing this reader will currently be prevented or false otherwise

setAllowClose

public void setAllowClose(boolean allowClose)

Allows to specify whether closing this input stream shall currently be prevented. Calls of close() will then throw an ClosingNotAllowedException.

Parameters:

allowClose - Specify true here, if closing shall be prevented from now on or false otherwise.

close

public void close()
           throws java.io.IOException

Closes the decorated input stream, if that is currently allowed. Closing a previously closed stream has no effect..

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.InputStream

Throws:

ClosingNotAllowedException - if isAllowClose() currently returns true. (Calling this method, if the decorated stream was already closed will also throw this exception, if closing is currently not allowed.)

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

See Also:

setAllowClose(boolean), Reader.close()

read

public int read()
         throws java.io.IOException

Returns the next byte from the decorated stream or -1 if either the end of the decorated stream or the limit specified to this stream have been reached.

Specified by:

read in class java.io.InputStream

Returns:

the next byte from the decorated stream or -1

Throws:

java.io.IOException

markSupported

public boolean markSupported()

Overrides:

markSupported in class java.io.InputStream

available

public int available()
              throws java.io.IOException

Overrides:

available in class java.io.InputStream

Throws:

java.io.IOException

mark

public void mark(int readAheadLimit)

Overrides:

mark in class java.io.InputStream

reset

public void reset()
           throws java.io.IOException

Overrides:

reset in class java.io.InputStream

Throws:

java.io.IOException

skip

public long skip(long n)
          throws java.io.IOException

Overrides:

skip in class java.io.InputStream

Throws:

java.io.IOException