spring boot 实现excel转pdf代码

要实现 Spring Boot 中的 Excel 转 PDF，你可以使用 Apache POI 和 iText 这两个库。以下是一个简单的示例代码：

1. 添加 Maven 依赖

在 pom.xml 文件中添加以下依赖：

<dependencies>
    <!-- Apache POI -->
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi</artifactId>
        <version>5.0.0</version>
    </dependency>
    <dependency>
        <groupId>org.apache.poi</groupId>
        <artifactId>poi-ooxml</artifactId>
        <version>5.0.0</version>
    </dependency>
    <!-- iText -->
    <dependency>
        <groupId>com.itextpdf</groupId>
        <artifactId>itextpdf</artifactId>
        <version>5.5.13</version>
    </dependency>
</dependencies>

2. 编写转换代码

import com.itextpdf.text.Document;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.pdf.PdfWriter;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;

public class ExcelToPdfConverter {

    public void convert(InputStream excelInputStream, OutputStream pdfOutputStream) throws Exception {
        // 创建 Excel Workbook
        Workbook workbook = new XSSFWorkbook(excelInputStream);
        // 创建 PDF Document
        Document document = new Document(PageSize.LETTER);
        PdfWriter.getInstance(document, pdfOutputStream);
        document.open();
        // 将每个 Sheet 转换为 PDF
        for (int i = 0; i < workbook.getNumberOfSheets(); i++) {
            SheetToPdfConverter sheetToPdfConverter = new SheetToPdfConverter();
            sheetToPdfConverter.convert(workbook.getSheetAt(i), document);
        }
        document.close();
        workbook.close();
    }

    private static class SheetToPdfConverter {

        public void convert(Sheet sheet, Document document) throws Exception {
            // 获取行数和列数
            int rowCount = sheet.getPhysicalNumberOfRows();
            int columnCount = sheet.getRow(0).getPhysicalNumberOfCells();
            // 创建 PDF 表格
            PdfPTable table = new PdfPTable(columnCount);
            // 填充 PDF 表格
            for (int i = 0; i < rowCount; i++) {
                Row row = sheet.getRow(i);
                for (int j = 0; j < columnCount; j++) {
                    Cell cell = row.getCell(j);
                    if (cell != null) {
                        table.addCell(cell.toString());
                    } else {
                        table.addCell("");
                    }
                }
            }
            // 添加 PDF 表格到 PDF Document
            document.add(table);
        }
    }
}

3. 调用转换方法

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletResponse;
import java.io.InputStream;
import java.io.OutputStream;

@Controller
public class ExcelToPdfController {

    @PostMapping("/convert")
    public void convert(@RequestParam("file") MultipartFile excelFile, HttpServletResponse response) throws Exception {
        InputStream excelInputStream = excelFile.getInputStream();
        OutputStream pdfOutputStream = response.getOutputStream();
        response.setContentType("application/pdf");
        response.setHeader("Content-Disposition", "attachment;filename=output.pdf");
        ExcelToPdfConverter converter = new ExcelToPdfConverter();
        converter.convert(excelInputStream, pdfOutputStream);
    }
}

这个示例代码将 Excel 文件转换为 PDF 并将其发送给客户端下载。你可以根据自己的需求进行修改。