php pdfparser不适用于pdf版本1.7

Question

我正在使用pdfparser来解析pdf文件中的文本。对于旧版本的pdf文件，它可以工作，但对于新版本的pdf文件，这个解析器不能工作。我的pdf版本是1.7

<?php
  include 'vendor/autoload.php'; 
  // Parse pdf file and build necessary objects.
  $parser = new Smalot\PdfParser\Parser();
  $pdf    = $parser->parseFile('sample.pdf'); 
  // Retrieve all pages from the pdf file.
  $pages  = $pdf->getPages(); 
  // Loop over each page to extract text.
  $content=array();
  foreach ($pages as $page) {
      $content[]= $page->getTextArray();  
    echo"<pre>";
    print_r($content);

  }

Answer 1

我也经历过同样的行为！

现在，我使用一个工具检查pdf版本，然后再尝试解析它。如果不是1.4，我将其转换为1.4，然后进行解析。如果需要，这里有一个php库：https://github.com/xthiago/pdf-version-converter

代码示例：

function searchablePdfParser($systemPath) {
    //we save the file to a temporay file because we might need to convert it.
    $tempPath = getPathWithIdAndTimestamp($systemPath) . 'tmp.pdf';
    copy($systemPath, $tempPath);
    //check whether it needs to be converted and convert it if required
    $guesser = new RegexGuesser();
    $pdfVersion = $guesser->guess($tempPath); // will print something like '1.4'
    if ( $pdfVersion != '1.4' ) {
        $command = new GhostscriptConverterCommand();
        $filesystem = new Filesystem();
        $converter = new GhostscriptConverter($command, $filesystem);
        $converter->convert($tempPath, '1.4');
    }
    //parse the original file or the converted file if it hadn't been a pdf 1.4 version
    $parser = new \Smalot\PdfParser\Parser();
    $pdf = $parser->parseFile($tempPath);
    $text = $pdf->getText();  
    unlink($tempPath);
    if ( strlen($text) < 30 ) {
        return '';
    }
    return $text;
}