Package org.apache.commons.io.input.buffer

Class PeekableInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

org.apache.commons.io.input.buffer.CircularBufferInputStream

org.apache.commons.io.input.buffer.PeekableInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class PeekableInputStream
extends CircularBufferInputStream

Implements a buffered input stream, which allows to peek into the buffers first bytes. This comes in handy when manually implementing scanners, lexers, parsers, and the like.

Since:

2.7

Field Summary

Fields inherited from class org.apache.commons.io.input.buffer.CircularBufferInputStream

buffer, bufferSize

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor	Description
PeekableInputStream(InputStream inputStream)	Constructs a new instance, which filters the given input stream, and uses a reasonable default buffer size (IOUtils.DEFAULT_BUFFER_SIZE).
PeekableInputStream(InputStream inputStream, int bufferSize)	Constructs a new instance, which filters the given input stream, and uses the given buffer size.

Method Summary

Modifier and Type	Method	Description
boolean	peek(byte[] sourceBuffer)	Returns whether the next bytes in the buffer are as given by sourceBuffer.
boolean	peek(byte[] sourceBuffer, int offset, int length)	Returns whether the next bytes in the buffer are as given by sourceBuffer, {code offset}, and length.

Methods inherited from class org.apache.commons.io.input.buffer.CircularBufferInputStream

close, fillBuffer, haveBytes, read, read

Methods inherited from class java.io.FilterInputStream

available, mark, markSupported, read, reset, skip

Methods inherited from class java.lang.Object

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

Constructor Details

PeekableInputStream

public PeekableInputStream(InputStream inputStream)

Constructs a new instance, which filters the given input stream, and uses a reasonable default buffer size (IOUtils.DEFAULT_BUFFER_SIZE).

Parameters:

inputStream - The input stream, which is being buffered.

PeekableInputStream

public PeekableInputStream(InputStream inputStream,
 int bufferSize)

Constructs a new instance, which filters the given input stream, and uses the given buffer size.

Parameters:

inputStream - The input stream, which is being buffered.

bufferSize - The size of the CircularByteBuffer, which is used internally.

Method Details

peek

public boolean peek(byte[] sourceBuffer)
             throws IOException

Returns whether the next bytes in the buffer are as given by sourceBuffer. This is equivalent to peek(byte[], int, int) with offset == 0, and length == sourceBuffer.length

Parameters:

sourceBuffer - the buffer to compare against

Returns:

true if the next bytes are as given

Throws:

IOException - Refilling the buffer failed.

peek

public boolean peek(byte[] sourceBuffer,
 int offset,
 int length)
             throws IOException

Returns whether the next bytes in the buffer are as given by sourceBuffer, {code offset}, and length.

Parameters:

sourceBuffer - the buffer to compare against

offset - the start offset

length - the length to compare

Returns:

true if the next bytes in the buffer are as given

Throws:

IOException - if there is a problem calling fillBuffer()