pdfbox exception :java.lang.ExceptionInInitializerError

在使用pdfbox过程中出现错误：

File sourceFile = new File(fileName);
		PDDocument doc = PDDocument.load(sourceFile);
		ImageIO.scanForPlugins();
		PDFRenderer renderer = new PDFRenderer(doc);
		int pageCount = doc.getNumberOfPages();
		BufferedImage[] images = new BufferedImage[pageCount];
for (int i = 0; i < pageCount; ++i) {
			BufferedImage image = null;
	renderer.renderImageWithDPI(i, 160, ImageType.GRAY);
	images[i] = image;
}

Exception in thread “main” java.lang.ExceptionInInitializerError
at org.apache.pdfbox.pdmodel.font.FontMapperImpl.getProvider(FontMapperImpl.java:149)
at org.apache.pdfbox.pdmodel.font.FontMapperImpl.findFont(FontMapperImpl.java:413)
at org.apache.pdfbox.pdmodel.font.FontMapperImpl.getTrueTypeFont(FontMapperImpl.java:321)
at org.apache.pdfbox.pdmodel.font.PDTrueTypeFont.(PDTrueTypeFont.java:219)
at org.apache.pdfbox.pdmodel.font.PDFontFactory.createFont(PDFontFactory.java:75)
at org.apache.pdfbox.pdmodel.PDResources.getFont(PDResources.java:143)
at org.apache.pdfbox.contentstream.operator.text.SetFontAndSize.process(SetFontAndSize.java:60)
at org.apache.pdfbox.contentstream.PDFStreamEngine.processOperator(PDFStreamEngine.java:838)
at org.apache.pdfbox.contentstream.PDFStreamEngine.processStreamOperators(PDFStreamEngine.java:495)
at org.apache.pdfbox.contentstream.PDFStreamEngine.processStream(PDFStreamEngine.java:469)
at org.apache.pdfbox.contentstream.PDFStreamEngine.processPage(PDFStreamEngine.java:150)
at org.apache.pdfbox.rendering.PageDrawer.drawPage(PageDrawer.java:203)
at org.apache.pdfbox.rendering.PDFRenderer.renderImage(PDFRenderer.java:145)
at org.apache.pdfbox.rendering.PDFRenderer.renderImageWithDPI(PDFRenderer.java:94)
at error.ConvertPdf2tif.convertPdf2Tiff(ConvertPdf2tif.java:62)
at error.ConvertPdf2tif.main(ConvertPdf2tif.java:31)
Caused by: java.lang.IllegalArgumentException: No enum constant org.apache.pdfbox.pdmodel.font.FontFormat. T T F
at java.lang.Enum.valueOf(Enum.java:238)
at org.apache.pdfbox.pdmodel.font.FontFormat.valueOf(FontFormat.java:25)
at org.apache.pdfbox.pdmodel.font.FileSystemFontProvider.loadDiskCache(FileSystemFontProvider.java:408)
at org.apache.pdfbox.pdmodel.font.FileSystemFontProvider.(FileSystemFontProvider.java:217)
at org.apache.pdfbox.pdmodel.font.FontMapperImpl$DefaultFontProvider.(FontMapperImpl.java:130)
… 107 more

仔细研究源码发现pdfbox在读取字体信息是会存储到一个名为“.pdfbox.cache”的缓存文件中，该文件记录的是系统字体信息。
pdfbox 相关源码：
FileSystemFontProvider

   /**
   * Saves the font metadata cache to disk.
   */
  private void saveDiskCache()
  {
      BufferedWriter writer = null;
      try
      {
          File file = getDiskCacheFile();
          try
          {
              writer = new BufferedWriter(new FileWriter(file));
          }
          catch (SecurityException e)
          {
              return;
          }

          for (FSFontInfo fontInfo : fontInfoList)
          {
              writer.write(fontInfo.postScriptName.trim());
              writer.write("|");
              writer.write(fontInfo.format.toString());
              writer.write("|");
              if (fontInfo.cidSystemInfo != null)
              {
                  writer.write(fontInfo.cidSystemInfo.getRegistry() + '-' +
                               fontInfo.cidSystemInfo.getOrdering() + '-' +
                               fontInfo.cidSystemInfo.getSupplement());
              }
              writer.write("|");
              if (fontInfo.usWeightClass > -1)
              {
                  writer.write(Integer.toHexString(fontInfo.usWeightClass));
              }
              writer.write("|");
              if (fontInfo.sFamilyClass > -1)
              {
                  writer.write(Integer.toHexString(fontInfo.sFamilyClass));
              }
              writer.write("|");
              writer.write(Integer.toHexString(fontInfo.ulCodePageRange1));
              writer.write("|");
              writer.write(Integer.toHexString(fontInfo.ulCodePageRange2));
              writer.write("|");
              if (fontInfo.macStyle > -1)
              {
                  writer.write(Integer.toHexString(fontInfo.macStyle));
              }
              writer.write("|");
              if (fontInfo.panose != null)
              {
                  byte[] bytes = fontInfo.panose.getBytes();
                  for (int i = 0; i < 10; i ++)
                  {
                      String str = Integer.toHexString(bytes[i]);
                      if (str.length() == 1)
                      {
                          writer.write('0');
                      }
                      writer.write(str);
                  }
              }
              writer.write("|");
              writer.write(fontInfo.file.getAbsolutePath());
              writer.newLine();
          }
      }
      catch (IOException e)
      {
          LOG.warn("Could not write to font cache", e);
          LOG.warn("Installed fonts information will have to be reloaded for each start");
          LOG.warn("You can assign a directory to the 'pdfbox.fontcache' property");
      }
      finally
      {
          IOUtils.closeQuietly(writer);
      }
  }

  private File getDiskCacheFile()
  {
      String path = System.getProperty("pdfbox.fontcache");
      if (path == null)
      {
          path = System.getProperty("user.home");
          if (path == null)
          {
              path = System.getProperty("java.io.tmpdir");
          }
      }
      return new File(path, ".pdfbox.cache");
  }

Enum

 public static <T extends Enum<T>> T valueOf(Class<T> enumType,
                                              String name) {
      T result = enumType.enumConstantDirectory().get(name);
      if (result != null)
          return result;
      if (name == null)
          throw new NullPointerException("Name is null");
      throw new IllegalArgumentException(
          "No enum constant " + enumType.getCanonicalName() + "." + name);
  }

通过阅读以上源码结合报错信息，我们发现是pdfbox在读取改文件时出现乱码，我猜测是改文件内容的编码方式被改变，重命名了旧有文件，pdfbox生成新的缓存文件，通过对比发现，改文件编码确实被改变了，正确编码应该是ANSI，错误文件的编码是Unicode big endian。