| 1 | package be.nikiroo.utils; |
| 2 | |
| 3 | import java.io.ByteArrayInputStream; |
| 4 | import java.io.Closeable; |
| 5 | import java.io.File; |
| 6 | import java.io.FileInputStream; |
| 7 | import java.io.IOException; |
| 8 | import java.io.InputStream; |
| 9 | |
| 10 | /** |
| 11 | * This class represents an image data. |
| 12 | * |
| 13 | * @author niki |
| 14 | */ |
| 15 | public class Image implements Closeable { |
| 16 | static private File tempRoot; |
| 17 | static private TempFiles tmpRepository; |
| 18 | static private long count = 0; |
| 19 | static private Object lock = new Object(); |
| 20 | |
| 21 | private File data; |
| 22 | |
| 23 | /** |
| 24 | * Do not use -- for serialisation purposes only. |
| 25 | */ |
| 26 | @SuppressWarnings("unused") |
| 27 | private Image() { |
| 28 | } |
| 29 | |
| 30 | /** |
| 31 | * Create a new {@link Image} with the given data. |
| 32 | * |
| 33 | * @param data |
| 34 | * the data |
| 35 | */ |
| 36 | public Image(byte[] data) { |
| 37 | ByteArrayInputStream in = new ByteArrayInputStream(data); |
| 38 | try { |
| 39 | this.data = getTemporaryFile(); |
| 40 | IOUtils.write(in, this.data); |
| 41 | } catch (IOException e) { |
| 42 | throw new RuntimeException(e); |
| 43 | } finally { |
| 44 | try { |
| 45 | in.close(); |
| 46 | } catch (IOException e) { |
| 47 | throw new RuntimeException(e); |
| 48 | } |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | /** |
| 53 | * Create a new {@link Image} from its Base64 representation. |
| 54 | * |
| 55 | * @param base64 |
| 56 | * the {@link Image} in Base64 format |
| 57 | * |
| 58 | * @throws IOException |
| 59 | * in case of I/O error |
| 60 | */ |
| 61 | public Image(String base64) throws IOException { |
| 62 | this(Base64.decode(base64)); |
| 63 | } |
| 64 | |
| 65 | /** |
| 66 | * Create a new {@link Image} from a stream. |
| 67 | * |
| 68 | * @param in |
| 69 | * the stream |
| 70 | * |
| 71 | * @throws IOException |
| 72 | * in case of I/O error |
| 73 | */ |
| 74 | public Image(InputStream in) throws IOException { |
| 75 | data = getTemporaryFile(); |
| 76 | IOUtils.write(in, data); |
| 77 | } |
| 78 | |
| 79 | /** |
| 80 | * Generate an {@link InputStream} for this {@link Image}. |
| 81 | * <p> |
| 82 | * This {@link InputStream} will (always) be a new one, and <b>you</b> are |
| 83 | * responsible for it. |
| 84 | * <p> |
| 85 | * Note: take care that the {@link InputStream} <b>must not</b> live past |
| 86 | * the {@link Image} life time! |
| 87 | * |
| 88 | * @return the stream |
| 89 | * |
| 90 | * @throws IOException |
| 91 | * in case of I/O error |
| 92 | */ |
| 93 | public InputStream newInputStream() throws IOException { |
| 94 | return new FileInputStream(data); |
| 95 | } |
| 96 | |
| 97 | /** |
| 98 | * <b>Read</b> the actual image data, as a byte array. |
| 99 | * <p> |
| 100 | * Note: if possible, prefer the {@link Image#newInputStream()} method, as |
| 101 | * it can be more efficient. |
| 102 | * |
| 103 | * @return the image data |
| 104 | */ |
| 105 | public byte[] getData() { |
| 106 | try { |
| 107 | InputStream in = newInputStream(); |
| 108 | try { |
| 109 | return IOUtils.toByteArray(in); |
| 110 | } finally { |
| 111 | in.close(); |
| 112 | } |
| 113 | } catch (IOException e) { |
| 114 | throw new RuntimeException(e); |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | /** |
| 119 | * Convert the given {@link Image} object into a Base64 representation of |
| 120 | * the same {@link Image} object. |
| 121 | * <p> |
| 122 | * Note: if possible, prefer the {@link Image#newInputStream()} method, as |
| 123 | * it can be more efficient. |
| 124 | * |
| 125 | * @return the Base64 representation |
| 126 | */ |
| 127 | public String toBase64() { |
| 128 | try { |
| 129 | return StringUtils.base64(getData(), false); |
| 130 | } catch (IOException e) { |
| 131 | throw new RuntimeException(e); |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | /** |
| 136 | * Closing the {@link Image} will delete the associated temporary file on |
| 137 | * disk. |
| 138 | * <p> |
| 139 | * Note that even if you don't, the program will still <b>try</b> to delete |
| 140 | * all the temporary files at JVM termination. |
| 141 | */ |
| 142 | @Override |
| 143 | public void close() throws IOException { |
| 144 | data.delete(); |
| 145 | synchronized (lock) { |
| 146 | count--; |
| 147 | if (count <= 0) { |
| 148 | count = 0; |
| 149 | tmpRepository.close(); |
| 150 | tmpRepository = null; |
| 151 | } |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | @Override |
| 156 | protected void finalize() throws Throwable { |
| 157 | try { |
| 158 | close(); |
| 159 | } finally { |
| 160 | super.finalize(); |
| 161 | } |
| 162 | } |
| 163 | |
| 164 | /** |
| 165 | * Return a newly created temporary file to work on. |
| 166 | * |
| 167 | * @return the file |
| 168 | * |
| 169 | * @throws IOException |
| 170 | * in case of I/O error |
| 171 | */ |
| 172 | private File getTemporaryFile() throws IOException { |
| 173 | synchronized (lock) { |
| 174 | if (tmpRepository == null) { |
| 175 | tmpRepository = new TempFiles(tempRoot, "images"); |
| 176 | count = 0; |
| 177 | } |
| 178 | |
| 179 | count++; |
| 180 | |
| 181 | return tmpRepository.createTempFile("image"); |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | /** |
| 186 | * Change the temporary root directory used by the program. |
| 187 | * <p> |
| 188 | * Caution: the directory will be <b>owned</b> by the system, all its files |
| 189 | * now belong to us (and will most probably be deleted). |
| 190 | * <p> |
| 191 | * Note: it may take some time until the new temporary root is used, we |
| 192 | * first need to make sure the previous one is not used anymore (i.e., we |
| 193 | * must reach a point where no unclosed {@link Image} remains in memory) to |
| 194 | * switch the temporary root. |
| 195 | * |
| 196 | * @param root |
| 197 | * the new temporary root, which will be <b>owned</b> by the |
| 198 | * system |
| 199 | */ |
| 200 | public static void setTemporaryFilesRoot(File root) { |
| 201 | tempRoot = root; |
| 202 | } |
| 203 | } |