Question

我不确定此错误消息实际指向的是什么。要清楚，我知道NullPointerException是什么，但我无法弄清楚什么是null，不应该是。有人知道导致此错误的原因是什么？

感谢。

com.lowagie.text.DocumentException: java.lang.NullPointerException
    at com.lowagie.text.pdf.PdfDocument.add(Unknown Source)
    at com.lowagie.text.Document.add(Unknown Source)
...
Caused by: java.lang.NullPointerException
    at com.lowagie.text.pdf.PdfPTable.getRowHeight(Unknown Source)
    at com.lowagie.text.pdf.PdfPTable.calculateHeights(Unknown Source)
    at com.lowagie.text.pdf.PdfPTable.setTotalWidth(Unknown Source)
    at com.lowagie.text.pdf.ColumnText.goComposite(Unknown Source)
    at com.lowagie.text.pdf.ColumnText.go(Unknown Source)
    at com.lowagie.text.pdf.PdfPCell.getMaxHeight(Unknown Source)
    at com.lowagie.text.pdf.PdfPRow.calculateHeights(Unknown Source)
    at com.lowagie.text.pdf.PdfPRow.getMaxHeights(Unknown Source)
    at com.lowagie.text.pdf.PdfPTable.getRowHeight(Unknown Source)
    at com.lowagie.text.pdf.PdfPTable.calculateHeights(Unknown Source)
    at com.lowagie.text.pdf.PdfPTable.setTotalWidth(Unknown Source)
    at com.lowagie.text.pdf.ColumnText.goComposite(Unknown Source)
    at com.lowagie.text.pdf.ColumnText.go(Unknown Source)
    at com.lowagie.text.pdf.ColumnText.go(Unknown Source)
    at com.lowagie.text.pdf.PdfDocument.addPTable(Unknown Source)
    ... 97 more

有问题的代码：

    this.getDocument().open();
    Element body = this.getBody();
    System.out.println(body);
    System.out.println(this.getDocument().toString());
    this.getDocument().add(body);//it errors out here!
    this.getDocument().close();

调试语句返回：

com.lowagie.text.pdf.PdfPTable@1fa0c8f
com.lowagie.text.Document@14eb497

Answer 1

我得到了完全相同的错误和堆栈跟踪，并通过切换到OpenPDF来解决问题。

OpenPDF基于iText 4，并有一些额外的错误修复和NPE修复。正在积极维护OpenPDF。

https://github.com/LibrePDF/OpenPDF

com.lowagie.text.Document.add的NullPointerException（元素e）

1 个答案: