将 Excel 文件 (xls,xlsx) 转换为 PDF

Question

我必须将 Excel 文件 (xls,xlsx) 转换为 PDF，但我正在寻找更好的方法，但我不确定以下示例是否最适合我：

https://www.grapecity.com/en/blogs/use-excel-api-to-convert-spreadsheets-to-pdfs-in-java

我在这里没有找到好的帖子和答案，有人有更好的例子吗？

Java save xls file as PDF

以一种简单的方式，我只需要以更好、更简单的方式将 excel 转换为 java 中的 pdf，而无需阅读整个 excel。

我找到了这个例子，它完全符合我的需要，但是由于许可证的原因不能使用它：

https://kbdeveloper.qoppa.com/sample-java-code-to-convert-excel-to-pdf-using-jofficeconvert/

提前致谢！

Answer 1

要转换 xls：

1. 将 xls 输入流转换为 html 输入流

2. html 输入流转换为 pdf 输出流

3. 这个 pdf outstream 可以写入所需的 pdf 文件，或者可以返回以供进一步使用

   public byte[] convertMsXlsBytesToPdfBytes() {
   byte[] pdfBytes = null;
   try {
       ByteArrayOutputStream pdfOutStream = new ByteArrayOutputStream();
       String fileName = "Doc Naming convention.xls";
       InputStream inputStream = new FileInputStream(fileName);
   
       //convert xls stream to html - w3 document
       org.w3c.dom.Document w3Document = ExcelToHtmlConverter.process(inputStream);
   
       //convert above w3 document to html input stream
       ByteArrayOutputStream htmlOutputStream = new ByteArrayOutputStream();
       Source xmlSource = new DOMSource(w3Document);
       Result outputTarget = new StreamResult(htmlOutputStream);
       TransformerFactory.newInstance().newTransformer().transform(xmlSource, outputTarget);
       InputStream htmlInputStream = new ByteArrayInputStream(htmlOutputStream.toByteArray());
   
       //convert html inputstream to pdf out stream
       ConverterProperties converterProperties = new ConverterProperties();
       HtmlConverter.convertToPdf(htmlInputStream, pdfOutStream, converterProperties);
   
       pdfBytes = pdfOutStream.toByteArray();
   
       //write to physical pdf file
       OutputStream out = new FileOutputStream(fileName.substring(0, fileName.indexOf(".")) + ".pdf");
       out.write(pdfBytes);
       out.close();
   } catch (Exception e) {
       // log exception details and throw custom exception
   }
   return pdfBytes; //bytes array I'm returning as per my requirement
   

   }

Answer 2

经过这么多测试，我说服他们我使用的第一个解决方案是正确的：

import java.io.FileInputStream;
    import java.io.*;
    import org.apache.poi.hssf.usermodel.HSSFWorkbook;
    import org.apache.poi.hssf.usermodel.HSSFSheet;
    import org.apache.poi.ss.usermodel.*;
    import java.util.Iterator;
   import com.itextpdf.text.*;
    import com.itextpdf.text.pdf.*;

    public class excel2pdf {  
            public static void main(String[] args) throws Exception{

                    FileInputStream input_document = new FileInputStream(new File("C:\\excel_to_pdf.xls"));
                    // Read workbook into HSSFWorkbook
                    HSSFWorkbook my_xls_workbook = new HSSFWorkbook(input_document); 
                    // Read worksheet into HSSFSheet
                    HSSFSheet my_worksheet = my_xls_workbook.getSheetAt(0); 
                    // To iterate over the rows
                    Iterator<Row> rowIterator = my_worksheet.iterator();
                    //We will create output PDF document objects at this point
                    Document iText_xls_2_pdf = new Document();
                    PdfWriter.getInstance(iText_xls_2_pdf, new FileOutputStream("Excel2PDF_Output.pdf"));
                    iText_xls_2_pdf.open();
                    //we have two columns in the Excel sheet, so we create a PDF table with two columns
                    //Note: There are ways to make this dynamic in nature, if you want to.
                    PdfPTable my_table = new PdfPTable(2);
                    //We will use the object below to dynamically add new data to the table
                    PdfPCell table_cell;
                    //Loop through rows.
                    while(rowIterator.hasNext()) {
                            Row row = rowIterator.next(); 
                            Iterator<Cell> cellIterator = row.cellIterator();
                                    while(cellIterator.hasNext()) {
                                            Cell cell = cellIterator.next(); //Fetch CELL
                                            switch(cell.getCellType()) { //Identify CELL type
                                                    //you need to add more code here based on
                                                    //your requirement / transformations
                                            case Cell.CELL_TYPE_STRING:
                                                    //Push the data from Excel to PDF Cell
                                                     table_cell=new PdfPCell(new Phrase(cell.getStringCellValue()));
                                                     //feel free to move the code below to suit to your needs
                                                     my_table.addCell(table_cell);
                                                    break;
                                            }
                                            //next line
                                    }

                    }
                    //Finally add the table to PDF document
                    iText_xls_2_pdf.add(my_table);                       
                    iText_xls_2_pdf.close();                
                    //we created our pdf file..
                    input_document.close(); //close xls
            }
    }

非常感谢您的帮助！