Class LimitedInputStream

java.lang.Object

java.io.InputStream

org.refcodes.io.LimitedInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class LimitedInputStream
extends InputStream

A LimitedInputStream wraps an InputStream and exposes at most a fixed number of bytes from it. Once the configured limit is reached, all read operations behave as if end of stream was reached (returning -1). This is useful when parsing framed or section based binary formats where a component must not read beyond its assigned payload region.

Constructor Summary

Constructors

Constructor	Description
LimitedInputStream(InputStream aInputStream, long aLimit)	Creates a LimitedInputStream that allows reading at most aLimit bytes from the provided stream.
LimitedInputStream(InputStream aInputStream, long aLimit, boolean isDelegateClose)	Creates a LimitedInputStream that allows reading at most aLimit bytes from the provided stream.

Method Summary

Modifier and Type	Method	Description
int	available()
void	close()	Closes this stream.
void	mark(int readlimit)
boolean	markSupported()
int	read()
int	read(byte[] b, int off, int len)
long	remaining()	Returns how many bytes are still available within the limit.
void	reset()
long	skip(long n)

Methods inherited from class InputStream

nullInputStream, read, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Methods inherited from class Object

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

Constructor Details

LimitedInputStream

public LimitedInputStream(InputStream aInputStream,
 long aLimit)

Creates a LimitedInputStream that allows reading at most aLimit bytes from the provided stream. The wrapped stream is not closed by this wrapper.

Parameters:

aInputStream - The underlying stream to read from

aLimit - The maximum number of bytes that can be read, must be >= 0

Throws:

NullPointerException - if aInputStream is null

IllegalArgumentException - if aLimit is negative

LimitedInputStream

public LimitedInputStream(InputStream aInputStream,
 long aLimit,
 boolean isDelegateClose)

Creates a LimitedInputStream that allows reading at most aLimit bytes from the provided stream. The wrapped stream is not closed by this wrapper depending on the according constructor's delegate close flag.

Parameters:

aInputStream - The underlying stream to read from

aLimit - The maximum number of bytes that can be read, must be >= 0

isDelegateClose - If true, then close() closes the wrapped stream. If false, then close() is a no-op.

Throws:

NullPointerException - if aInputStream is null

IllegalArgumentException - if aLimit is negative

Method Details

remaining

public long remaining()

Returns how many bytes are still available within the limit.

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

read

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

Overrides:

read in class InputStream

Throws:

IOException

skip

public long skip(long n)
          throws IOException

Overrides:

skip in class InputStream

Throws:

IOException

available

public int available()
              throws IOException

Overrides:

available in class InputStream

Throws:

IOException

mark

public void mark(int readlimit)

Overrides:

mark in class InputStream

reset

public void reset()
           throws IOException

Overrides:

reset in class InputStream

Throws:

IOException

markSupported

public boolean markSupported()

Overrides:

markSupported in class InputStream

close

public void close()
           throws IOException

Closes this stream. If this instance was created with isDelegateClose == true, then the underlying stream is closed as well. Otherwise this method is a no-op, which is convenient when reading a limited payload from a larger container stream.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException