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*
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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package javax.imageio.stream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.RandomAccessFile;
import com.sun.imageio.stream.CloseableDisposerRecord;
import com.sun.imageio.stream.StreamFinalizer;
import sun.java2d.Disposer;
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.
/**
* An implementation of <code>ImageInputStream</code> that gets its
* input from a <code>File</code> or <code>RandomAccessFile</code>.
* The file contents are assumed to be stable during the lifetime of
* the object.
*
*/
public class FileImageInputStream extends ImageInputStreamImpl {
private RandomAccessFile raf;
The referent to be registered with the Disposer. /** The referent to be registered with the Disposer. */
private final Object disposerReferent;
The DisposerRecord that closes the underlying RandomAccessFile. /** The DisposerRecord that closes the underlying RandomAccessFile. */
private final CloseableDisposerRecord disposerRecord;
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.
Params: - 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.
/**
* Constructs a <code>FileImageInputStream</code> that will read
* from a given <code>File</code>.
*
* <p> The file contents must not change between the time this
* object is constructed and the time of the last call to a read
* method.
*
* @param f a <code>File</code> to read from.
*
* @exception IllegalArgumentException if <code>f</code> is
* <code>null</code>.
* @exception SecurityException if a security manager exists
* and does not allow read access to the file.
* @exception FileNotFoundException if <code>f</code> is a
* directory or cannot be opened for reading for any other reason.
* @exception IOException if an I/O error occurs.
*/
public FileImageInputStream(File f)
throws FileNotFoundException, IOException {
this(f == null ? null : new RandomAccessFile(f, "r"));
}
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.
Params: - raf – a
RandomAccessFile to read from.
Throws: - IllegalArgumentException – if
raf is
null.
/**
* Constructs a <code>FileImageInputStream</code> that will read
* from a given <code>RandomAccessFile</code>.
*
* <p> The file contents must not change between the time this
* object is constructed and the time of the last call to a read
* method.
*
* @param raf a <code>RandomAccessFile</code> to read from.
*
* @exception IllegalArgumentException if <code>raf</code> is
* <code>null</code>.
*/
public FileImageInputStream(RandomAccessFile raf) {
if (raf == null) {
throw new IllegalArgumentException("raf == null!");
}
this.raf = raf;
disposerRecord = new CloseableDisposerRecord(raf);
if (getClass() == FileImageInputStream.class) {
disposerReferent = new Object();
Disposer.addRecord(disposerReferent, disposerRecord);
} else {
disposerReferent = new StreamFinalizer(this);
}
}
public int read() throws IOException {
checkClosed();
bitOffset = 0;
int val = raf.read();
if (val != -1) {
++streamPos;
}
return val;
}
public int read(byte[] b, int off, int len) throws IOException {
checkClosed();
bitOffset = 0;
int nbytes = raf.read(b, off, len);
if (nbytes != -1) {
streamPos += nbytes;
}
return nbytes;
}
Returns the length of the underlying file, or -1
if it is unknown.
Returns: the file length as a long, or
-1.
/**
* Returns the length of the underlying file, or <code>-1</code>
* if it is unknown.
*
* @return the file length as a <code>long</code>, or
* <code>-1</code>.
*/
public long length() {
try {
checkClosed();
return raf.length();
} catch (IOException e) {
return -1L;
}
}
public void seek(long pos) throws IOException {
checkClosed();
if (pos < flushedPos) {
throw new IndexOutOfBoundsException("pos < flushedPos!");
}
bitOffset = 0;
raf.seek(pos);
streamPos = raf.getFilePointer();
}
public void close() throws IOException {
super.close();
disposerRecord.dispose(); // this closes the RandomAccessFile
raf = null;
}
{@inheritDoc}
/**
* {@inheritDoc}
*/
protected void finalize() throws Throwable {
// Empty finalizer: for performance reasons we instead use the
// Disposer mechanism for ensuring that the underlying
// RandomAccessFile is closed prior to garbage collection
}
}