src/main/java/eu/svjatoslav/meviz/htmlindexer/Utils.java

   1 /*
   2  * Meviz - Various tools collection to work with multimedia.
   3  * Copyright (C) 2012, Svjatoslav Agejenko, svjatoslav@svjatoslav.eu
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of version 2 of the GNU General Public License
   7  * as published by the Free Software Foundation.
   8  */
   9
  10 package eu.svjatoslav.meviz.htmlindexer;
  11
  12 import java.awt.image.BufferedImage;
  13 import java.io.BufferedReader;
  14 import java.io.File;
  15 import java.io.FileNotFoundException;
  16 import java.io.FileReader;
  17 import java.io.IOException;
  18 import java.util.HashSet;
  19 import java.util.zip.CRC32;
  20
  21 import javax.imageio.ImageIO;
  22
  23 import eu.svjatoslav.meviz.htmlindexer.layouts.MixedLayout;
  24
  25 public class Utils {
  26
  27         private static File lastLoadedFile;
  28
  29         private static BufferedImage lastLoadedBufferedImage;
  30
  31         /**
  32          * Load image into {@link BufferedImage} and return it. Caches last loaded
  33          * image to speed up subsequent loading attempts.
  34          *
  35          * @throws ImageFormatError
  36          * @throws IOException
  37          */
  38         public static BufferedImage getBufferedImage(final File file)
  39                         throws ImageFormatError, IOException {
  40                 if (file.equals(lastLoadedFile))
  41                         return lastLoadedBufferedImage;
  42
  43                 System.out.println("Loading image: " + file.getPath());
  44                 lastLoadedBufferedImage = ImageIO.read(file);
  45                 lastLoadedFile = file;
  46
  47                 if (lastLoadedBufferedImage == null)
  48                         throw new ImageFormatError("File: " + file
  49                                         + " is not a valid image.");
  50
  51                 return lastLoadedBufferedImage;
  52         }
  53
  54         public static File getLayoutIndexFile(final Layout layout,
  55                         final File directoryToIndex) {
  56
  57                 final String indexFilePath = directoryToIndex.getAbsolutePath()
  58                                 + "/index" + layout.getFileNameSuffix() + ".html";
  59
  60                 return new File(indexFilePath);
  61         }
  62
  63         public static HashSet<Layout> getLayouts() {
  64                 final HashSet<Layout> layouts = new HashSet<Layout>();
  65                 layouts.add(new MixedLayout());
  66                 return layouts;
  67         }
  68
  69         public static String getStringCrcAsHex(final String input) {
  70
  71                 // create a new CRC-calculating object
  72                 final CRC32 crc = new CRC32();
  73
  74                 // loop, calculating CRC for each byte of the string
  75                 // There is no CRC16.update(byte[]) method.
  76                 for (final byte b : input.getBytes())
  77                         crc.update(b);
  78
  79                 // note use crc.value, not crc.getValue()
  80                 final String hex = Integer.toHexString((int) crc.getValue())
  81                                 .toUpperCase();
  82
  83                 // System.out.println("Input string: " + input);
  84                 // System.out.println("Result: " + hex);
  85
  86                 return hex;
  87         }
  88
  89         public static File getThumbnailsDirectory(final File directoryToIndex) {
  90                 return new File(getThumbnailsDirectoryPath(directoryToIndex));
  91         }
  92
  93         public static String getThumbnailsDirectoryPath(final File directoryToIndex) {
  94                 return directoryToIndex.getAbsolutePath() + "/"
  95                                 + Constants.THUMBNAILS_DIRECTORY_NAME + "/";
  96         }
  97
  98         public static boolean isMevizGeneratedIndexFile(final File indexFile)
  99                         throws FileNotFoundException, IOException {
 100
 101                 boolean isMevizFile = false;
 102
 103                 final FileReader fileReader = new FileReader(indexFile);
 104                 final BufferedReader reader = new BufferedReader(fileReader);
 105
 106                 parseFile: {
 107                         while (true) {
 108                                 final String line = reader.readLine();
 109
 110                                 if (line == null)
 111                                         break parseFile;
 112
 113                                 if (line.contains(Constants.HTML_MAGIC_STRING)) {
 114                                         isMevizFile = true;
 115                                         break parseFile;
 116                                 }
 117                         }
 118                 }
 119
 120                 reader.close();
 121                 fileReader.close();
 122                 return isMevizFile;
 123         }
 124
 125 }