Module openj9.dtfj

Package com.ibm.dtfj.corereaders

Class ClosingFileReader

java.lang.Object

javax.imageio.stream.ImageInputStreamImpl

com.ibm.dtfj.corereaders.ClosingFileReader

All Implemented Interfaces:

ResourceReleaser, Closeable, DataInput, AutoCloseable, ImageInputStream

public class ClosingFileReader
extends ImageInputStreamImpl
implements ResourceReleaser

A wrapper around the functionality that we require from RandomAccessFiles but with the added auto-closing functionality that we require. Since it is not always easy to determine who "owns" a file and we do not want to introduce the concept of state, this class will manage all such file ownership. We now also extend javax.imageio.stream.ImageInputStreamImpl as a convenient common interface that we can share with the zebedee corefile reader

Field Summary

Fields declared in class javax.imageio.stream.ImageInputStreamImpl

bitOffset, byteOrder, flushedPos, streamPos

Constructor Summary

Constructors

Constructor	Description
ClosingFileReader(File file)
ClosingFileReader(File file, boolean deleteOnCloseOrExit)	Create a closing file reader which can close/delete the backing file on shutdown
ClosingFileReader(ImageInputStream file)	Create a closing file reader from a stream

Method Summary

Modifier and Type	Method	Description
String	getAbsolutePath()
URI	getURIOfFile()
boolean	isMVSFile()
int	read(byte[] buffer)	Currently this attempts to fill the entire buffer
int	read(byte[] buffer, int bStart, int length)	Reads up to len bytes from the stream, and stores them into b starting at index off.
byte[]	readBytes(int n)
InputStream	streamFromFile()

Methods declared in class javax.imageio.stream.ImageInputStreamImpl

checkClosed, close, finalize, flush, flushBefore, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, isCached, isCachedFile, isCachedMemory, length, mark, read, readBit, readBits, readBoolean, readByte, readBytes, readChar, readDouble, readFloat, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, seek, setBitOffset, setByteOrder, skipBytes, skipBytes

Methods declared in class java.lang.Object

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

Methods declared in interface com.ibm.dtfj.corereaders.ResourceReleaser

releaseResources

Constructor Detail

ClosingFileReader

public ClosingFileReader(File file)
                  throws IOException

Throws:

IOException

ClosingFileReader

public ClosingFileReader(ImageInputStream file)
                  throws IOException

Create a closing file reader from a stream

Parameters:

file - An ImageInputStream

Throws:

FileNotFoundException

IOException

ClosingFileReader

public ClosingFileReader(File file,
                         boolean deleteOnCloseOrExit)
                  throws IOException

Create a closing file reader which can close/delete the backing file on shutdown

Parameters:

file -

deleteOnCloseOrExit - Whether to delete the file when the file is closed or at shutdown

Throws:

FileNotFoundException

IOException

Method Detail

readBytes

public byte[] readBytes(int n)
                 throws IOException

Throws:

IOException

read

public int read(byte[] buffer,
                int bStart,
                int length)
         throws IOException

Description copied from class: javax.imageio.stream.ImageInputStreamImpl

Reads up to len bytes from the stream, and stores them into b starting at index off. If no bytes can be read because the end of the stream has been reached, -1 is returned.

The bit offset within the stream must be reset to zero before the read occurs.

Subclasses must provide an implementation for this method. The subclass implementation should update the stream position before exiting.

Specified by:

read in interface ImageInputStream

Specified by:

read in class ImageInputStreamImpl

Parameters:

buffer -

bStart -

length -

Returns:

The number of bytes actually read

Throws:

IOException

read

public int read(byte[] buffer)
         throws IOException

Currently this attempts to fill the entire buffer

Specified by:

read in interface ImageInputStream

Overrides:

read in class ImageInputStreamImpl

Parameters:

buffer - an array of bytes to be written to.

Returns:

the number of bytes actually read, or -1 to indicate EOF.

Throws:

IOException - if an I/O error occurs.

streamFromFile

public InputStream streamFromFile()
                           throws FileNotFoundException

Returns:

A new stream for reading from the underlying file

Throws:

FileNotFoundException - If this file has moved since the ClosingFileReader was created (since we would have failed in the constructor if the file was ever there)

getURIOfFile

public URI getURIOfFile()

getAbsolutePath

public String getAbsolutePath()

isMVSFile

public boolean isMVSFile()