如何读取PDF表格数据？现有方案存问题求推荐最优解法

Hey there! I totally get the frustration of dealing with wonky table formatting when converting PDFs to Excel—let's break down better alternatives to your current approaches.

First, a quick reality check: Apache POI is built for working with Office documents (like Excel itself), not parsing PDFs. That's why converting the entire PDF to a flat string and shoving it into Excel causes those annoying column offsets—you're losing all the structural context of the table. And hardcoding exact coordinates? Yeah, that's a nightmare to maintain if the PDF layout ever shifts even a little.

Here are some far better solutions:

• Use a dedicated PDF table extraction library
  Tools like Tabula-java (the Java port of the popular Tabula tool) are built specifically for identifying and extracting table data from PDFs. It analyzes the visual structure of the document to detect rows, columns, and cell boundaries, so you don't end up with content spilling into wrong columns. You can extract the table data as a structured list of rows/columns, then use Apache POI to write that organized data directly into Excel. This is by far the most reliable approach for most cases.

• Leverage Apache PDFBox with dynamic structural parsing
  If you prefer sticking with Apache's ecosystem, PDFBox lets you extract text along with its positional coordinates (x/y values). Instead of hardcoding fixed coordinates, you can write flexible logic to group text elements:

  1. Extract all text chunks along with their position data.
  2. Sort chunks by y-coordinate to group into rows, then by x-coordinate to order columns.
  3. Define small threshold ranges for x-values to group chunks into columns (accounting for minor spacing variations).
     This is way more adaptable than hardcoding coordinates because it can handle slight layout tweaks.

• Add OCR if dealing with scanned PDFs
  If your PDF is a scanned image (not editable text), you'll need an OCR tool like Tesseract combined with table detection logic (like Tesseract's built-in table support). Once you extract text with positional data, you can use the same grouping logic as above to structure the table properly.

To recap: Dedicated table extraction libraries like Tabula-java are the best bet for avoiding column offsets and preserving table structure. Hardcoding coordinates is brittle, and plain string conversion loses all structural info—neither is ideal for long-term use.

内容的提问来源于stack exchange，提问作者dperuj