Package org.apache.tika.utils

Class RereadableInputStream

java.lang.Object

java.io.InputStream

org.apache.tika.utils.RereadableInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

public class RereadableInputStream
extends InputStream

Wraps an input stream, reading it only once, but making it available for rereading an arbitrary number of times. The stream's bytes are stored in memory up to a user specified maximum, and then stored in a temporary file which is deleted when this class' close() method is called.

Constructor Summary

Constructors

Constructor	Description
RereadableInputStream(InputStream inputStream, int maxBytesInMemory, boolean readToEndOfStreamOnFirstRewind, boolean closeOriginalStreamOnClose)	Creates a rereadable input stream.

Method Summary

Modifier and Type	Method	Description
void	close()	Closes the input stream and removes the temporary file if one was created.
int	getSize()	Returns the number of bytes read from the original stream.
int	read()	Reads a byte from the stream, saving it in the store if it is being read from the original stream.
void	rewind()	"Rewinds" the stream to the beginning for rereading.

Methods inherited from class java.io.InputStream

available, mark, markSupported, nullInputStream, read, read, readAllBytes, readNBytes, readNBytes, reset, skip, transferTo

Methods inherited from class java.lang.Object

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

Constructor Detail

RereadableInputStream

public RereadableInputStream(InputStream inputStream,
                             int maxBytesInMemory,
                             boolean readToEndOfStreamOnFirstRewind,
                             boolean closeOriginalStreamOnClose)

Creates a rereadable input stream.

Parameters:

inputStream - stream containing the source of data

maxBytesInMemory - maximum number of bytes to use to store the stream's contents in memory before switching to disk; note that the instance will preallocate a byte array whose size is maxBytesInMemory. This byte array will be made available for garbage collection (i.e. its reference set to null) when the content size exceeds the array's size, when close() is called, or when there are no more references to the instance.

readToEndOfStreamOnFirstRewind - Specifies whether or not to read to the end of stream on first rewind. If this is set to false, then when rewind() is first called, only those bytes already read from the original stream will be available from then on.

Method Detail

read

public int read()
         throws IOException

Reads a byte from the stream, saving it in the store if it is being read from the original stream. Implements the abstract InputStream.read().

Specified by:

read in class InputStream

Returns:

the read byte, or -1 on end of stream.

Throws:

IOException

rewind

public void rewind()
            throws IOException

"Rewinds" the stream to the beginning for rereading.

Throws:

IOException

close

public void close()
           throws IOException

Closes the input stream and removes the temporary file if one was created.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class InputStream

Throws:

IOException

getSize

public int getSize()

Returns the number of bytes read from the original stream.

Returns:

number of bytes read