java - 转换为 BufferedImage 时 PDFBox 错误 : NoClassDefFoundError: org/apache/fontbox/FontBoxFont

Question

我正在尝试使用 PDFBox 将 PDF 文档转换为 .png 文件。我关注了this answer了解需要哪些依赖项并给我一个起点。当我尝试遍历页面并创建 BufferedImage 时，我收到了一个 NoClassDefFoundError 错误。它正在寻找 org/apache/fontbox/FontBoxFont，但通过一些广泛的谷歌搜索，我没有找到关于 FontBoxFont 的信息。这是一个需要包含的单独的 jar 吗？是什么导致了这个错误？项目中包含以下 .jar:

pdfbox-2.0.2.jar
levigo-jbig2-imageio-1.6.5.jar
pdfbox-tools-2.0.2.jar
jai-imageio-core-1.3.1.jar
commons-logging-1.2.jar

这里是主要方法:

public static void main(String[] args) {

    String sourceDir = "C:/Dev/Workspace/PdfToPng/Stocks.pdf";
    String destinationDir = "C:/Dev/Workspace/PdfToPng/pages/";

    try {
        PDDocument document = PDDocument.load(new File(sourceDir));
        PDFRenderer pdfRenderer = new PDFRenderer(document);
        for(int page = 0; page < document.getNumberOfPages(); ++page) {
            BufferedImage bim = pdfRenderer.renderImageWithDPI(page, 300, ImageType.RGB);
            ImageIOUtil.writeImage(bim, destinationDir + (page+1) + ".png", 300);
        }
        document.close();
    } catch(Exception e) {
        System.out.println(e.getStackTrace());
    }
}

错误是在 BufferedImage bim = pdfRenderer.renderImageWithDPI(page, 300, ImageType.RGB);

上引发的

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/fontbox/FontBoxFont
    at org.apache.pdfbox.pdmodel.font.PDFontFactory.createFont(PDFontFactory.java:75)
    at org.apache.pdfbox.pdmodel.PDResources.getFont(PDResources.java:123)
    at org.apache.pdfbox.contentstream.operator.text.SetFontAndSize.process(SetFontAndSize.java:60)
    at org.apache.pdfbox.contentstream.PDFStreamEngine.processOperator(PDFStreamEngine.java:815)
    at org.apache.pdfbox.contentstream.PDFStreamEngine.processStreamOperators(PDFStreamEngine.java:472)
    at org.apache.pdfbox.contentstream.PDFStreamEngine.processStream(PDFStreamEngine.java:446)
    at org.apache.pdfbox.contentstream.PDFStreamEngine.processPage(PDFStreamEngine.java:149)
    at org.apache.pdfbox.rendering.PageDrawer.drawPage(PageDrawer.java:189)
    at org.apache.pdfbox.rendering.PDFRenderer.renderPage(PDFRenderer.java:208)
    at org.apache.pdfbox.rendering.PDFRenderer.renderImage(PDFRenderer.java:139)
    at org.apache.pdfbox.rendering.PDFRenderer.renderImageWithDPI(PDFRenderer.java:94)
    at PdfToPng.main(PdfToPng.java:25)
Caused by: java.lang.ClassNotFoundException: org.apache.fontbox.FontBoxFont
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 12 more

Answer 1

显然，您需要将 Apache FontBox 2.0.2 添加到您的类路径中，您可以从 mvnrepository 中获取它