在GlyphMapping中PDFClown NullPointerException

Question

我最近將我的代碼從PDFClown v0.1.2切換到v0.1.2.1。 我認為我現在已經遇到了一些差異（改變了TextMarkup（）的構造函數並從CallOutNote切換到StaticNote）但不幸的是我遇到了一些麻煩，我還沒弄清楚如何修復它。

這是堆棧跟蹤：

Exception in thread "Thread-0" java.lang.ExceptionInInitializerError
at org.pdfclown.documents.contents.fonts.Encoding.put(Encoding.java:88)
at org.pdfclown.documents.contents.fonts.StandardEncoding.<init>(StandardEncoding.java:41)
at org.pdfclown.documents.contents.fonts.Encoding.<clinit>(Encoding.java:54)
at org.pdfclown.documents.contents.fonts.SimpleFont.getBaseEncoding(SimpleFont.java:82)
at org.pdfclown.documents.contents.fonts.SimpleFont.loadEncoding(SimpleFont.java:142)
at org.pdfclown.documents.contents.fonts.SimpleFont.onLoad(SimpleFont.java:170)
at org.pdfclown.documents.contents.fonts.Font.load(Font.java:878)
at org.pdfclown.documents.contents.fonts.Font.<init>(Font.java:368)
at org.pdfclown.documents.contents.fonts.SimpleFont.<init>(SimpleFont.java:65)
at org.pdfclown.documents.contents.fonts.TrueTypeFont.<init>(TrueTypeFont.java:47)
at org.pdfclown.documents.contents.fonts.Font.wrap(Font.java:262)
at org.pdfclown.documents.contents.FontResources.wrap(FontResources.java:72)
at org.pdfclown.documents.contents.FontResources.wrap(FontResources.java:1)
at org.pdfclown.documents.contents.ResourceItems.get(ResourceItems.java:119)
at org.pdfclown.documents.contents.objects.SetFont.getResource(SetFont.java:119)
at org.pdfclown.documents.contents.objects.SetFont.getFont(SetFont.java:83)
at org.pdfclown.documents.contents.objects.SetFont.scan(SetFont.java:97)
at org.pdfclown.documents.contents.ContentScanner.moveNext(ContentScanner.java:1360)
at org.pdfclown.documents.contents.ContentScanner$TextWrapper.extract(ContentScanner.java:819)
at org.pdfclown.documents.contents.ContentScanner$TextWrapper.<init>(ContentScanner.java:771)
at org.pdfclown.documents.contents.ContentScanner$TextWrapper.<init>(ContentScanner.java:764)
at org.pdfclown.documents.contents.ContentScanner$GraphicsObjectWrapper.get(ContentScanner.java:684)
at org.pdfclown.documents.contents.ContentScanner$GraphicsObjectWrapper.access$0(ContentScanner.java:676)
at org.pdfclown.documents.contents.ContentScanner.getCurrentWrapper(ContentScanner.java:1184)
at org.pdfclown.tools.TextExtractor.extract(TextExtractor.java:636)
at org.pdfclown.tools.TextExtractor.extract(TextExtractor.java:653)
at org.pdfclown.tools.TextExtractor.extract(TextExtractor.java:653)
at org.pdfclown.tools.TextExtractor.extract(TextExtractor.java:299)
at theproject.logic.WorkerThread.extractTextOfHighlight(WorkerThread.java:758)
at theproject.logic.WorkerThread.run(WorkerThread.java:107)
Caused by: java.lang.NullPointerException
at java.io.Reader.<init>(Reader.java:78)
at java.io.InputStreamReader.<init>(InputStreamReader.java:72)
at org.pdfclown.documents.contents.fonts.GlyphMapping.load(GlyphMapping.java:69)
at org.pdfclown.documents.contents.fonts.GlyphMapping.<clinit>(GlyphMapping.java:47)
... 30 more

方法“extractTextOfHighlight（）”提取突出顯示的文檔中的文本：

protected List<ITextString> extractTextOfHighlight(Rectangle2D rect2d, Page page) {
    TextExtractor extractor = new TextExtractor();

    List<Rectangle2D> areas = new ArrayList<Rectangle2D>();
    areas.add(rect2d);
    extractor.setAreas(areas);
    extractor.setAreaTolerance(2.0);

    Map<Rectangle2D, List<ITextString>> map = extractor.extract(page);
    // Util.printExtractedTextMapToConsole(map);
    for(Rectangle2D keyRect : map.keySet()) {
        return validateExtractedStrings(map.get(keyRect));
    }

    return null;
}

StackExchange上有一篇帖子，它是唯一描述類似錯誤的帖子：

https://stackoverflow.com/a/23804322

我已經在PDFClown中應用了推薦的修復，但遇到了同樣的錯誤。 我的問題是，如果有什么我可以做的來解決這個錯誤。 我真的沒有想法。

這是我用於測試的pdf： https ： //www.dropbox.com/s/pt32s7gbrvr21a8/testfile.pdf？dl = 0

Answer 1

請確認您已正確構建PDF Clown jar。

您的異常最初是作為NullPointerException發生的

at java.io.Reader.<init>(Reader.java:78)
at java.io.InputStreamReader.<init>(InputStreamReader.java:72)
at org.pdfclown.documents.contents.fonts.GlyphMapping.load(GlyphMapping.java:69)
at org.pdfclown.documents.contents.fonts.GlyphMapping.<clinit>(GlyphMapping.java:47)

即在GlyphMapping.load期間

  glyphListStream = new BufferedReader(
    new InputStreamReader(
      GlyphMapping.class.getResourceAsStream("/fonts/AGL20.scsv")
      )
    );

無法找到資源"/fonts/AGL20.scsv" （這會導致getResourceAsStream返回null ， InputStreamReader構造函數將其轉發到其父類Reader構造函數，該構造函數將其參數與null進行比較，並且在相等的情況下拋出顯式NullPointerException ）。