Class FileImageInputStream

java.lang.Object
javax.imageio.stream.ImageInputStreamImpl
javax.imageio.stream.FileImageInputStream
All Implemented Interfaces:
Closeable, DataInput, AutoCloseable, ImageInputStream 
public class FileImageInputStream extends ImageInputStreamImpl
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 declared in class javax.imageio.stream.ImageInputStreamImpl

bitOffset, byteOrder, flushedPos, streamPos

Constructor Summary

Constructor Description
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

Modifier and Type Method Description
protected void finalize()
Deprecated.
The finalize method has been deprecated.
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 int between 0 and 255.
int read(byte[] b, int off, int len)
Reads up to len bytes from the stream, and stores them into b starting at index off.

Methods declared in class javax.imageio.stream.ImageInputStreamImpl

checkClosed, close, flush, flushBefore, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, isCached, isCachedFile, isCachedMemory, 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

Constructor Details

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 - if f is null.
SecurityException - if a security manager exists and does not allow read access to the file.
FileNotFoundException - if f is a directory or cannot be opened for reading for any other reason.
IOException - 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 - if raf is null.

Method Details

read

public int read() throws IOException
Description copied from class: ImageInputStreamImpl
Reads a single byte from the stream and returns it as an int between 0 and 255. If EOF is reached, -1 is returned.

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

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

Specified by:
read in interface ImageInputStream
Specified by:
read in class ImageInputStreamImpl
Returns:
the value of the next byte in the stream, or -1 if EOF is reached.
Throws:
IOException - if the stream has been closed.

read

public int read(byte[] b, int off, int len) throws IOException
Description copied from class: 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:
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 - 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 in interface ImageInputStream
Overrides:
length in class ImageInputStreamImpl
Returns:
the file length as a long, or -1.

finalize

@Deprecated(since="9") protected void finalize() throws Throwable
Deprecated.
The finalize method has been deprecated. Subclasses that override finalize in order to perform cleanup should be modified to use alternative cleanup mechanisms and to remove the overriding finalize method. When overriding the finalize method, its implementation must explicitly ensure that super.finalize() is invoked as described in Object.finalize(). See the specification for Object.finalize() for further information about migration options.
Finalizes this object prior to garbage collection. The close method is called to close any open input source. This method should not be called from application code.
Overrides:
finalize in class ImageInputStreamImpl
Throws:
Throwable - if an error occurs during superclass finalization.
See Also:

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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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https://docs.oracle.com/en/java/javase/17/docs/api/java.desktop/javax/imageio/stream/FileImageInputStream.html