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前言

最近遇到生成 Excel 并转 PDF 的需求，磕磕碰碰总结三种方式，分别是 POI + iText 库，EasyExcel + iText 库和直接生成 PDF 表格三种方式。

本文基于 EasyExcel + iText 库实现，并将自定义 pdf 上 title 内容，将生成的 pdf 文件返回。

转换前后效果

引入 pom 配置

<dependency><groupId>com.alibaba</groupId><artifactId>easyexcel</artifactId><version>3.3.2</version>
</dependency>
<dependency><groupId>com.alibaba</groupId><artifactId>easyexcel-core</artifactId><version>3.3.2</version><scope>compile</scope>
</dependency>
<dependency><groupId>com.itextpdf</groupId><artifactId>itextpdf</artifactId><version>5.5.13</version>

代码实现

定义 ExcelDataVo 对象

@Data
public class ExcelDataVo implements Serializable {private static final long serialVersionUID = 1L;/**生成pdf的文件路径*/private String pdfFilePath;/**生成pdf的文件标题*/private String title;
}

主方法

import com.alibaba.excel.EasyExcel;
import com.alibaba.fastjson.JSON;
import lombok.extern.slf4j.Slf4j;@Slf4j
public class ExcelConvertService {public static void main(String[] args) throws Exception {// 需要进行转换的excelString fileName = "D:\\\\对账明细报告.xlsx";// 重点:通过创建监听器并且将当前创建的对象传递进去ExcelDataVo excelDataVo = new ExcelDataVo();excelDataVo.setTitle("对账明细报告");EasyExcel.read(fileName, new NoModelDataListener(excelDataVo)).sheet().doRead();log.info("读取完成:{}", JSON.toJSONString(excelDataVo));}

EasyExcel 监听器

import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
import com.alibaba.excel.metadata.data.ReadCellData;
import com.alibaba.excel.util.ConverterUtils;
import com.itextpdf.text.*;
import com.itextpdf.text.Font;
import com.itextpdf.text.pdf.BaseFont;
import com.itextpdf.text.pdf.PdfPCell;
import com.itextpdf.text.pdf.PdfPTable;
import com.itextpdf.text.pdf.PdfWriter;
import lombok.extern.slf4j.Slf4j;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;@Slf4j
public class NoModelDataListener extends AnalysisEventListener<Map<Integer, String>> {// 存储读取到 excel 的每一行private List<Map<Integer, String>> cachedDataList = new ArrayList<>();// 存储读取到 excel 的列头private Map<Integer, String> cachedHead = new HashMap<>();//自定义返回结果类，也就是与传递给controller的实体类ExcelDataVo excelDataVo;//重点:通过构造器把 excelDataVo 对象传递过来public NoModelDataListener(ExcelDataVo excelDataVo) {this.excelDataVo = excelDataVo;}@Overridepublic void invoke(Map<Integer, String> data, AnalysisContext context) {cachedDataList.add(data);}@Overridepublic void invokeHead(Map<Integer, ReadCellData<?>> headMap, AnalysisContext context) {cachedHead = ConverterUtils.convertToStringMap(headMap, context);}@Overridepublic void doAfterAllAnalysed(AnalysisContext context) {String pdfFilePath = "D:\\对账明细报告.pdf";try (FileOutputStream fos = new FileOutputStream(pdfFilePath)) {// 创建PDF文档对象Document document = new Document(PageSize.A2, 50, 50, 50, 50);// 创建PDF输出流PdfWriter writer = PdfWriter.getInstance(document, fos);// 打开PDF文档document.open();// 创建PDF表格对象PdfPTable table = new PdfPTable(cachedDataList.get(0).size());table.setHeaderRows(1);//table.setWidths(new float[] {1, 2, 2, 2});// 设置表格宽度table.setWidthPercentage(100);// 设置表格标题//String sheetName = context.readSheetHolder().getSheetName();String sheetName = excelDataVo.getTitle();Paragraph title = new Paragraph(sheetName, new Font(BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED), 16, Font.BOLD));title.setAlignment(Element.ALIGN_CENTER);document.add(title);// 添加表格标题for (Map.Entry<Integer, String> entry : cachedHead.entrySet()) {String value = entry.getValue();PdfPCell pdfCell = new PdfPCell(new Paragraph(value, new Font(BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED), 12)));pdfCell.setBorderWidth(1f);pdfCell.setBorderColor(BaseColor.BLACK);pdfCell.setPadding(5f);pdfCell.setBackgroundColor(BaseColor.LIGHT_GRAY);table.addCell(pdfCell);}// 添加表格内容for (Map<Integer, String> map : cachedDataList) {for (Map.Entry<Integer, String> entry : map.entrySet()) {PdfPCell pdfCell = new PdfPCell(new Paragraph(entry.getValue()));pdfCell.setBorderWidth(1f);pdfCell.setBorderColor(BaseColor.BLACK);pdfCell.setPadding(5f);table.addCell(pdfCell);}}// 添加表格到PDF文档table.setSpacingBefore(20f);table.setSpacingAfter(20f);table.setKeepTogether(true);document.add(table);// 关闭PDF文档document.close();} catch (IOException | DocumentException e) {e.printStackTrace();}excelDataVo.setPdfFilePath(pdfFilePath);log.info("所有数据解析完成！");}
}

至此，就基于 EasyExcel 和 iText 库实现了 excel 转 pdf 的逻辑，并将外部的数据传递到监听器，也从监听器拿到返回的内容，其他的比如 service 传递到监听器也可以通过这种注入方式实现。