FileImageInputStream (Java 2 Platform SE 5.0) (original) (raw)

javax.imageio.stream

Class FileImageInputStream

java.lang.Object extended by javax.imageio.stream.ImageInputStreamImpl javax.imageio.stream.FileImageInputStream

All Implemented Interfaces:

public class FileImageInputStream

An implementation of ImageInputStream that gets its input from a File or RandomAccessFile. The file contents are assumed to be stable during the lifetime of the object.

Field Summary

Fields inherited from class javax.imageio.stream.ImageInputStreamImpl
bitOffset, byteOrder, flushedPos, streamPos

Constructor Summary
FileImageInputStream(File f) Constructs a FileImageInputStream that will read from a given File.
FileImageInputStream(RandomAccessFile raf) Constructs a FileImageInputStream that will read from a given RandomAccessFile.

Method Summary
void	close() Closes the stream.
long	length() Returns the length of the underlying file, or -1 if it is unknown.
int	read() Reads a single byte from the stream and returns it as an integer between 0 and 255.
int	[read](../../../javax/imageio/stream/FileImageInputStream.html#read%28byte[], int, int%29)(byte[] b, int off, int len) Reads up to len bytes from the stream, and stores them into b starting at index off.
void	seek(long pos) Sets the current stream position to the desired location.

Methods inherited from class javax.imageio.stream.ImageInputStreamImpl
checkClosed, finalize, flush, flushBefore, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, isCached, isCachedFile, isCachedMemory, mark, read, readBit, readBits, readBoolean, readByte, [readBytes](../../../javax/imageio/stream/ImageInputStreamImpl.html#readBytes%28javax.imageio.stream.IIOByteBuffer, int%29), readChar, readDouble, readFloat, readFully, [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28byte[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28char[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28double[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28float[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28int[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28long[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28short[], int, int%29), readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, setBitOffset, setByteOrder, skipBytes, skipBytes

Methods inherited from class javax.imageio.stream.ImageInputStreamImpl

checkClosed, finalize, flush, flushBefore, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, isCached, isCachedFile, isCachedMemory, mark, read, readBit, readBits, readBoolean, readByte, [readBytes](../../../javax/imageio/stream/ImageInputStreamImpl.html#readBytes%28javax.imageio.stream.IIOByteBuffer, int%29), readChar, readDouble, readFloat, readFully, [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28byte[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28char[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28double[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28float[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28int[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28long[], int, int%29), [readFully](../../../javax/imageio/stream/ImageInputStreamImpl.html#readFully%28short[], int, int%29), readInt, readLine, readLong, readShort, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, setBitOffset, setByteOrder, skipBytes, skipBytes

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, [wait](../../../java/lang/Object.html#wait%28long, int%29)

Constructor Detail

FileImageInputStream

public FileImageInputStream(File f) throws FileNotFoundException, IOException

Constructs a FileImageInputStream that will read from a given File.

The file contents must not change between the time this object is constructed and the time of the last call to a read method.

Parameters:

f - a File to read from.

Throws:

[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang") - if f isnull.

[SecurityException](../../../java/lang/SecurityException.html "class in java.lang") - if a security manager exists and does not allow read access to the file.

[FileNotFoundException](../../../java/io/FileNotFoundException.html "class in java.io") - if f is a directory or cannot be opened for reading for any other reason.

[IOException](../../../java/io/IOException.html "class in java.io") - if an I/O error occurs.

FileImageInputStream

public FileImageInputStream(RandomAccessFile raf)

Constructs a FileImageInputStream that will read from a given RandomAccessFile.

The file contents must not change between the time this object is constructed and the time of the last call to a read method.

Parameters:

raf - a RandomAccessFile to read from.

Throws:

[IllegalArgumentException](../../../java/lang/IllegalArgumentException.html "class in java.lang") - if raf isnull.

Method Detail

read

public int read() throws IOException

Description copied from interface: [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html#read%28%29)

Reads a single byte from the stream and returns it as an integer between 0 and 255. If the end of the stream is reached, -1 is returned.

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

Specified by:

[read](../../../javax/imageio/stream/ImageInputStream.html#read%28%29) in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")

Specified by:

[read](../../../javax/imageio/stream/ImageInputStreamImpl.html#read%28%29) in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")

Returns:

a byte value from the stream, as an int, or -1 to indicate EOF.

Throws:

[IOException](../../../java/io/IOException.html "class in java.io") - if an I/O error occurs.

read

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

Description copied from class: [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html#read%28byte[], int, int%29)

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](../../../javax/imageio/stream/ImageInputStream.html#read%28byte[], int, int%29) in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")

Specified by:

[read](../../../javax/imageio/stream/ImageInputStreamImpl.html#read%28byte[], int, int%29) in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")

Parameters:

b - an array of bytes to be written to.

off - the starting position within b to write to.

len - the maximum number of bytes to read.

Returns:

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

Throws:

[IOException](../../../java/io/IOException.html "class in java.io") - if an I/O error occurs.

length

public long length()

Returns the length of the underlying file, or -1 if it is unknown.

Specified by:

[length](../../../javax/imageio/stream/ImageInputStream.html#length%28%29) in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")

Overrides:

[length](../../../javax/imageio/stream/ImageInputStreamImpl.html#length%28%29) in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")

Returns:

the file length as a long, or-1.

seek

public void seek(long pos) throws IOException

Description copied from interface: [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html#seek%28long%29)

Sets the current stream position to the desired location. The next read will occur at this location. The bit offset is set to 0.

An IndexOutOfBoundsException will be thrown ifpos is smaller than the flushed position (as returned by getflushedPosition).

It is legal to seek past the end of the file; anEOFException will be thrown only if a read is performed.

Specified by:

[seek](../../../javax/imageio/stream/ImageInputStream.html#seek%28long%29) in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")

Overrides:

[seek](../../../javax/imageio/stream/ImageInputStreamImpl.html#seek%28long%29) in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")

Parameters:

pos - a long containing the desired file pointer position.

Throws:

[IOException](../../../java/io/IOException.html "class in java.io") - if any other I/O error occurs.

close

public void close() throws IOException

Description copied from interface: [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html#close%28%29)

Closes the stream. Attempts to access a stream that has been closed may result in IOExceptions or incorrect behavior. Calling this method may allow classes implementing this interface to release resources associated with the stream such as memory, disk space, or file descriptors.

Specified by:

[close](../../../javax/imageio/stream/ImageInputStream.html#close%28%29) in interface [ImageInputStream](../../../javax/imageio/stream/ImageInputStream.html "interface in javax.imageio.stream")

Overrides:

[close](../../../javax/imageio/stream/ImageInputStreamImpl.html#close%28%29) in class [ImageInputStreamImpl](../../../javax/imageio/stream/ImageInputStreamImpl.html "class in javax.imageio.stream")

Throws:

[IOException](../../../java/io/IOException.html "class in java.io") - if an I/O error occurs.

Submit a bug or feature
For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.