java使用iText解析PDF文件

public static String extractPdfText() throws IOException {
  PdfReader pdfReader = new PdfReader("D:\\lh\\官文文件\\商标部分驳回通知书_35943346_1561314244657.pdf");
  int pages = pdfReader.getNumberOfPages();
  String pdfText = "";
  for (int ctr = 1; ctr < pages + 1; ctr++) {
    pdfText += PdfTextExtractor.getTextFromPage(pdfReader, ctr); 
  }
  pdfReader.close();
  return pdfText;
}