这几天一直在忙工作中的事情,在工作中有一个问题,可能是因为刚开始接触这个EasyPoi,对其也没有太多的理解,在项目中就使用了,有一个需求,是要导出项目中所有的表格,今天就对这个需求进行分析和实现吧;
需求:导出项目中所有的表格,导出文件为Excel;
技术:EasyPoi (现在市面上非常流行的offic操作技术)
我一直在采用注解实现,就是为每个表格都实现一个ExportExcelVo这个一个后缀的实现类;
但是表格太多了,当时也没有什么好的办法,也是对EasyPoi的不熟悉吧,em...,说白了就是自己菜,在清明节放假这几天好好学习一下,
推复杂的表格推荐使用注解,实现类,可以精确到控制每个字段的格式化,样式,合并单元格等等属性;具体的去官网看;
但是这个需求并不复杂,而且表格也不复杂,本人还花费了大量时间,感觉到了知识的不足,但是每个人也不可能什么都会,最重要的不是什么都会,而是愿意花时间去学习,知识就是一点点累计的;
今天来讲一下EasyPoi导出Excel动态列,并控制列的宽度和顺序,和做的时候碰见的一些问题;
二话不说上代码
数据样例
Data.java
1 package ExcelExport; 2 3 /** 4 * Excel动态列导出 测试数据样例 5 */ 6 public interface Data {
// 列头1 7 String col1String = "{ " + 8 " "fileName":"存储名称", " + 9 " "fileType":"存储方式", " + 10 " "ip":"ip地址", " + 11 " "port":"端口号", " + 12 " "file":"存放路径", " + 13 " "bangFc":"绑定文件", " + 14 " "isEnabled":"是否启用", " + 15 " "createTime":"创建时间", " + 16 " "createName":"创建人姓名", " + 17 " "updateTime":"更新时间", " + 18 " "updateName":"更新人姓名" " + 19 "}";
// 列头2 20 String col2String = "{ " + 21 " "fileName":"存储名称", " + 22 " "fileType":"存储方式", " + 23 " "ip":"ip地址", " + 24 " "port":"端口号", " + 25 " "file":"存放路径", " + 26 " "bangFc":"绑定文件", " + 27 " "isEnabled":"是否启用" " + 28 "}"; 29
// 列宽 30 String colWidth = "{ " + 31 " "fileName":"15", " + 32 " "fileType":"15", " + 33 " "ip":"15", " + 34 " "port":"15", " + 35 " "file":"15", " + 36 " "bangFc":"15", " + 37 " "isEnabled":"15", " + 38 " "createTime":"20", " + 39 " "createName":"15", " + 40 " "updateTime":"20", " + 41 " "updateName":"15" " + 42 "}";
// 列数据 43 String data = "[ " + 44 " { " + 45 " "fileName": "测试ftp别名", " + 46 " "fileType": "ftp存储", " + 47 " "ip": "192.168.0.1", " + 48 " "port": "21", " + 49 " "file": "/archive", " + 50 " "bangFc": "电子档案", " + 51 " "isEnabled": "已启用", " + 52 " "createTime": "2020-03-09", " + 53 " "createName": "admin", " + 54 " "updateTime": "2020-03-09", " + 55 " "updateName": "zyg" " + 56 " }, " + 57 " { " + 58 " "fileName": "测试mongodb别名", " + 59 " "fileType": "mongodb存储", " + 60 " "ip": "192.168.0.2", " + 61 " "port": "27017", " + 62 " "file": "/archive", " + 63 " "bangFc": "电子档案", " + 64 " "isEnabled": "已启用", " + 65 " "createTime": "2020-03-09", " + 66 " "createName": "admin", " + 67 " "updateTime": "2020-03-09", " + 68 " "updateName": "zyg" " + 69 " } " + 70 "]"; 71 }
上面的就是定义的列头,列宽,数据
工具类ExcelExport
1 package ExcelExport.utils; 2 3 import cn.afterturn.easypoi.excel.ExcelExportUtil; 4 import cn.afterturn.easypoi.excel.entity.ExportParams; 5 import cn.afterturn.easypoi.excel.entity.params.ExcelExportEntity; 6 import com.alibaba.fastjson.JSONArray; 7 import com.alibaba.fastjson.JSONObject; 8 import org.apache.poi.ss.usermodel.Workbook; 9 10 import javax.servlet.http.HttpServletResponse; 11 import java.io.IOException; 12 import java.io.OutputStream; 13 import java.util.ArrayList; 14 import java.util.LinkedHashMap; 15 import java.util.List; 16 import java.util.Map; 17 18 /** 19 * @Description Excel工具类 20 * @ClassName ExcelUtils 21 * @Author mr.zhang 22 * @Date 2020/4/6 15:57 23 * @Version 1.0.0 24 **/ 25 public class ExcelUtils { 26 27 /** 28 * 导出Excel 动态列 29 * @param colTitle 动态列头 30 * @param colWidth 对应列宽 31 * @param dataList 数据集合 32 * @param tableTitle 表头 33 * @param sheetTitle sheet头 34 * @param response response 35 * @param downLoadName 下载文件名 36 * @throws IOException 37 */ 38 public static void exportDynamicExportExcel(String colTitle, String colWidth, String dataList, String tableTitle, String sheetTitle, HttpServletResponse response, String downLoadName) throws IOException { 39 40 // 解析列头 在这里用LinkedHashMap 做有序列 因为HashMap是没有顺序的 41 Map colTitleMap = JSONObject.parseObject(colTitle, LinkedHashMap.class); 42 // 列宽就不需要有序了 43 Map colWidthMap = JSONObject.parseObject(colWidth, Map.class); 44 45 // 列头容器 46 List<ExcelExportEntity> colList = new ArrayList<>(); 47 // 列头遍历 采用Foreach 48 colTitleMap.forEach((k, v) -> {
// 创建列对象 name k width 49 ExcelExportEntity excelExportEntity = new ExcelExportEntity(v.toString(), k, Integer.valueOf(colWidthMap.get(k).toString())); 50 colList.add(excelExportEntity); 51 }); 52 53 // 解析数据 54 JSONArray jsonArray = JSONObject.parseArray(dataList); 55 List<JSONObject> maps = jsonArray.toJavaList(JSONObject.class); 56 // 调用EasyPoi 返回workbook 57 Workbook workbook = ExcelExportUtil.exportExcel(new ExportParams(tableTitle, sheetTitle), colList, maps); 58 if (workbook != null) { 59 writeToWeb(workbook, response, downLoadName); 60 } 61 62 } 63
// 返回到Web 64 private static void writeToWeb(Workbook sheets, HttpServletResponse response, String fileName) throws IOException { 65 response.setContentType("application/vnd.ms-excel;charset=UTF-8"); 66 response.setCharacterEncoding("UTF-8"); 67 response.setHeader("Content-Disposition", "attachment;fileName=" + 68 java.net.URLEncoder.encode(fileName + ".xls", "UTF-8")); 69 OutputStream outputStream = response.getOutputStream(); 70 sheets.write(outputStream); 71 outputStream.flush(); 72 outputStream.close(); 73 } 74 75 }
最后安装到Maven的本地库就可以用了,如果公司存在Maven库可以发布到公司的Maven库中.
碰见的问题:
在Spring-boot项目中请采用easypoi场景启动器,防止依赖问题
列头顺序的问题,之前在解析列头的时候采用的是接口Map.class,发现导出之后列的顺序不可控,后来绝顶用LinkedHashMap.class,这样列的顺序就是你定义的顺序;
用到的依赖:
easypoi 场景启动器,servlet,fastJson
作者:彼岸舞
时间:2020 4 6
内容关于:POI
本文属于作者原创,未经允许,禁止转发