java - 使用 pdfbox.jar 将 pdf 文件转换为文本文件时，出现以下错误。如何解决这些问题？

Question

log4j:WARN No appenders could be found for logger (org.apache.pdfbox.util.PDFStreamEngine).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Exception in thread "main" java.lang.NoSuchMethodError: org.apache.fontbox.cmap.CMap.lookup(II)Ljava/lang/String;
    at org.apache.pdfbox.pdmodel.font.PDFont.cmapEncoding(PDFont.java:510)
    at org.apache.pdfbox.pdmodel.font.PDFont.encode(PDFont.java:535)
    at org.apache.pdfbox.util.PDFStreamEngine.processEncodedText(PDFStreamEngine.java:395)
    at org.apache.pdfbox.util.operator.ShowTextGlyph.process(ShowTextGlyph.java:62)
    at org.apache.pdfbox.util.PDFStreamEngine.processOperator(PDFStreamEngine.java:557)
    at org.apache.pdfbox.util.PDFStreamEngine.processSubStream(PDFStreamEngine.java:268)
    at org.apache.pdfbox.util.PDFStreamEngine.processSubStream(PDFStreamEngine.java:235)
    at org.apache.pdfbox.util.operator.Invoke.process(Invoke.java:75)
    at org.apache.pdfbox.util.PDFStreamEngine.processOperator(PDFStreamEngine.java:557)
    at org.apache.pdfbox.util.PDFStreamEngine.processSubStream(PDFStreamEngine.java:268)
    at org.apache.pdfbox.util.PDFStreamEngine.processSubStream(PDFStreamEngine.java:235)
    at org.apache.pdfbox.util.PDFStreamEngine.processStream(PDFStreamEngine.java:215)
    at org.apache.pdfbox.util.PDFTextStripper.processPage(PDFTextStripper.java:460)
    at org.apache.pdfbox.util.PDFTextStripper.processPages(PDFTextStripper.java:385)
    at org.apache.pdfbox.util.PDFTextStripper.writeText(PDFTextStripper.java:344)
    at org.apache.pdfbox.util.PDFTextStripper.getText(PDFTextStripper.java:257)
    at PDFConversionUsingPDFBox.main(PDFConversionUsingPDFBox.java:39)

Answer 1

您的类路径中似乎有不兼容版本的 pdfbox.jar 和 fontbox.jar。