J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2007 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package javax.imageio.stream; |
| 27 | |
| 28 | import java.io.File; |
| 29 | import java.io.FileNotFoundException; |
| 30 | import java.io.IOException; |
| 31 | import java.io.RandomAccessFile; |
| 32 | import com.sun.imageio.stream.CloseableDisposerRecord; |
| 33 | import com.sun.imageio.stream.StreamFinalizer; |
| 34 | import sun.java2d.Disposer; |
| 35 | |
| 36 | /** |
| 37 | * An implementation of <code>ImageInputStream</code> that gets its |
| 38 | * input from a <code>File</code> or <code>RandomAccessFile</code>. |
| 39 | * The file contents are assumed to be stable during the lifetime of |
| 40 | * the object. |
| 41 | * |
| 42 | */ |
| 43 | public class FileImageInputStream extends ImageInputStreamImpl { |
| 44 | |
| 45 | private RandomAccessFile raf; |
| 46 | |
| 47 | /** The referent to be registered with the Disposer. */ |
| 48 | private final Object disposerReferent; |
| 49 | |
| 50 | /** The DisposerRecord that closes the underlying RandomAccessFile. */ |
| 51 | private final CloseableDisposerRecord disposerRecord; |
| 52 | |
| 53 | /** |
| 54 | * Constructs a <code>FileImageInputStream</code> that will read |
| 55 | * from a given <code>File</code>. |
| 56 | * |
| 57 | * <p> The file contents must not change between the time this |
| 58 | * object is constructed and the time of the last call to a read |
| 59 | * method. |
| 60 | * |
| 61 | * @param f a <code>File</code> to read from. |
| 62 | * |
| 63 | * @exception IllegalArgumentException if <code>f</code> is |
| 64 | * <code>null</code>. |
| 65 | * @exception SecurityException if a security manager exists |
| 66 | * and does not allow read access to the file. |
| 67 | * @exception FileNotFoundException if <code>f</code> is a |
| 68 | * directory or cannot be opened for reading for any other reason. |
| 69 | * @exception IOException if an I/O error occurs. |
| 70 | */ |
| 71 | public FileImageInputStream(File f) |
| 72 | throws FileNotFoundException, IOException { |
| 73 | this(f == null ? null : new RandomAccessFile(f, "r")); |
| 74 | } |
| 75 | |
| 76 | /** |
| 77 | * Constructs a <code>FileImageInputStream</code> that will read |
| 78 | * from a given <code>RandomAccessFile</code>. |
| 79 | * |
| 80 | * <p> The file contents must not change between the time this |
| 81 | * object is constructed and the time of the last call to a read |
| 82 | * method. |
| 83 | * |
| 84 | * @param raf a <code>RandomAccessFile</code> to read from. |
| 85 | * |
| 86 | * @exception IllegalArgumentException if <code>raf</code> is |
| 87 | * <code>null</code>. |
| 88 | */ |
| 89 | public FileImageInputStream(RandomAccessFile raf) { |
| 90 | if (raf == null) { |
| 91 | throw new IllegalArgumentException("raf == null!"); |
| 92 | } |
| 93 | this.raf = raf; |
| 94 | |
| 95 | disposerRecord = new CloseableDisposerRecord(raf); |
| 96 | if (getClass() == FileImageInputStream.class) { |
| 97 | disposerReferent = new Object(); |
| 98 | Disposer.addRecord(disposerReferent, disposerRecord); |
| 99 | } else { |
| 100 | disposerReferent = new StreamFinalizer(this); |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | public int read() throws IOException { |
| 105 | checkClosed(); |
| 106 | bitOffset = 0; |
| 107 | int val = raf.read(); |
| 108 | if (val != -1) { |
| 109 | ++streamPos; |
| 110 | } |
| 111 | return val; |
| 112 | } |
| 113 | |
| 114 | public int read(byte[] b, int off, int len) throws IOException { |
| 115 | checkClosed(); |
| 116 | bitOffset = 0; |
| 117 | int nbytes = raf.read(b, off, len); |
| 118 | if (nbytes != -1) { |
| 119 | streamPos += nbytes; |
| 120 | } |
| 121 | return nbytes; |
| 122 | } |
| 123 | |
| 124 | /** |
| 125 | * Returns the length of the underlying file, or <code>-1</code> |
| 126 | * if it is unknown. |
| 127 | * |
| 128 | * @return the file length as a <code>long</code>, or |
| 129 | * <code>-1</code>. |
| 130 | */ |
| 131 | public long length() { |
| 132 | try { |
| 133 | checkClosed(); |
| 134 | return raf.length(); |
| 135 | } catch (IOException e) { |
| 136 | return -1L; |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | public void seek(long pos) throws IOException { |
| 141 | checkClosed(); |
| 142 | if (pos < flushedPos) { |
| 143 | throw new IndexOutOfBoundsException("pos < flushedPos!"); |
| 144 | } |
| 145 | bitOffset = 0; |
| 146 | raf.seek(pos); |
| 147 | streamPos = raf.getFilePointer(); |
| 148 | } |
| 149 | |
| 150 | public void close() throws IOException { |
| 151 | super.close(); |
| 152 | disposerRecord.dispose(); // this closes the RandomAccessFile |
| 153 | raf = null; |
| 154 | } |
| 155 | |
| 156 | /** |
| 157 | * {@inheritDoc} |
| 158 | */ |
| 159 | protected void finalize() throws Throwable { |
| 160 | // Empty finalizer: for performance reasons we instead use the |
| 161 | // Disposer mechanism for ensuring that the underlying |
| 162 | // RandomAccessFile is closed prior to garbage collection |
| 163 | } |
| 164 | } |