Excel导入和导出

首先在pom文件引入依赖

    <dependencies>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>3.0.5</version>
        </dependency>
    </dependencies>

后台代码实现导出excel文件到指定目录（导出）

先建一个dog类

import com.alibaba.excel.annotation.ExcelProperty;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Dog {

//    index 表示这个属性是在excel的第几列（从0开始），value 表示在当前列的表头名称
    @ExcelProperty("狗编号")
    private Integer dogNo;
    @ExcelProperty("狗名称")
    private String dogName;
    @ExcelProperty("狗年龄")
    private Integer dogAge;


}

然后测试类

import com.alibaba.excel.EasyExcel;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class Client {
    public static void main(String[] args) {
        //写入的路径
        String fileName = "D:\\Dog.xlsx";
        EasyExcel.write(fileName,Dog.class).sheet("狗").doWrite(getLists());
    }

    //模仿从后台拿到一个Dog对象的集合 (我生成了5个一样的dog狗)
    public static List<Dog> getLists(){
        return Stream.generate(()->new Dog(2,"阿花",28)).limit(5).collect(Collectors.toList());
    }
}

运行之后会看到路径下有个Dog.xlsx文件，效果如下：

后台代码实现读指定目录的excel文件（导入）

创建EasyListener类

import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
import java.util.Map;

public class EasyListener extends AnalysisEventListener<Dog> {

    //一行一行读取excel内容
    @Override
    public void invoke(Dog dog, AnalysisContext analysisContext) {
        System.out.println("数据"+dog);
    }

    //读取表头内容
    @Override
    public void invokeHeadMap(Map<Integer, String> headMap, AnalysisContext context) {
        System.out.println("表头:"+headMap);
    }

    //读取完之后
    @Override
    public void doAfterAllAnalysed(AnalysisContext analysisContext) {
        System.out.println("我读完了");
    }


}

测试类代码：

public class Client {
    public static void main(String[] args) {
        //写入的路径
        String fileName = "D:\\Dog.xlsx";
//        EasyExcel.write(fileName,Dog.class).sheet("狗").doWrite(getLists());

        EasyExcel.read(fileName,Dog.class,new EasyListener()).sheet("狗").doRead();
    }

    //模仿从后台拿到一个Dog对象的集合 (我生成了5个一样的dog狗)
    public static List<Dog> getLists(){
        return Stream.generate(()->new Dog(2,"阿花",28)).limit(5).collect(Collectors.toList());
    }
}

输出结果如下：

前端vue实现在浏览器导出excel（导出）

npm 下载 file-saver 和 xlsx 这两个依赖文件

npm install file-saver@1.3.8 xlsx@0.14.1 --save

导出js文件代码存放在这

Export2Excel.js代码整理好了，copy过去即可

/* eslint-disable */
import { saveAs } from 'file-saver'
import XLSX from 'xlsx'

function generateArray(table) {
  var out = [];
  var rows = table.querySelectorAll('tr');
  var ranges = [];
  for (var R = 0; R < rows.length; ++R) {
    var outRow = [];
    var row = rows[R];
    var columns = row.querySelectorAll('td');
    for (var C = 0; C < columns.length; ++C) {
      var cell = columns[C];
      var colspan = cell.getAttribute('colspan');
      var rowspan = cell.getAttribute('rowspan');
      cell.setAttribute('mso-number-format','\@');//mso-number-format:'\@';
      var cellValue = cell.innerText;
      if (cellValue !== "" && cellValue == +cellValue) cellValue = +cellValue;

      //Skip ranges
      ranges.forEach(function (range) {
        if (R >= range.s.r && R <= range.e.r && outRow.length >= range.s.c && outRow.length <= range.e.c) {
          for (var i = 0; i <= range.e.c - range.s.c; ++i) outRow.push(null);
        }
      });

      //Handle Row Span
      if (rowspan || colspan) {
        rowspan = rowspan || 1;
        colspan = colspan || 1;
        ranges.push({s: {r: R, c: outRow.length}, e: {r: R + rowspan - 1, c: outRow.length + colspan - 1}});
      }
      ;

      //Handle Value
      outRow.push(cellValue !== "" ? cellValue : null);

      //Handle Colspan
      if (colspan) for (var k = 0; k < colspan - 1; ++k) outRow.push(null);
    }
    out.push(outRow);
  }
  return [out, ranges];
};

function datenum(v, date1904) {
  if (date1904) v += 1462;
  var epoch = Date.parse(v);
  return (epoch - new Date(Date.UTC(1899, 11, 30))) / (24 * 60 * 60 * 1000);
}

function sheet_from_array_of_arrays(data, opts) {
  var ws = {};
  var range = {s: {c: 10000000, r: 10000000}, e: {c: 0, r: 0}};
  for (var R = 0; R != data.length; ++R) {
    for (var C = 0; C != data[R].length; ++C) {
      if (range.s.r > R) range.s.r = R;
      if (range.s.c > C) range.s.c = C;
      if (range.e.r < R) range.e.r = R;
      if (range.e.c < C) range.e.c = C;
      var cell = {v: data[R][C]};
      if (cell.v == null) continue;
      var cell_ref = XLSX.utils.encode_cell({c: C, r: R});

      if (typeof cell.v === 'number') cell.t = 'n';
      else if (typeof cell.v === 'boolean') cell.t = 'b';
      else if (cell.v instanceof Date) {
        cell.t = 'n';
        cell.z = XLSX.SSF._table[14];
        cell.v = datenum(cell.v);
      }
      else cell.t = 's';

      ws[cell_ref] = cell;
    }
  }
  if (range.s.c < 10000000) ws['!ref'] = XLSX.utils.encode_range(range);
  return ws;
}

function Workbook() {
  if (!(this instanceof Workbook)) return new Workbook();
  this.SheetNames = [];
  this.Sheets = {};
}

function s2ab(s) {
  var buf = new ArrayBuffer(s.length);
  var view = new Uint8Array(buf);
  for (var i = 0; i != s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF;
  return buf;
}

export function export_table_to_excel(id) {
  var theTable = document.getElementById(id);
  var oo = generateArray(theTable);
  var ranges = oo[1];

  /* original data */
  var data = oo[0];
  var ws_name = "SheetJS";

  var wb = new Workbook(), ws = sheet_from_array_of_arrays(data);

  /* add ranges to worksheet */
  // ws['!cols'] = ['apple', 'banan'];
  ws['!merges'] = ranges;

  /* add worksheet to workbook */
  wb.SheetNames.push(ws_name);
  wb.Sheets[ws_name] = ws;

  var wbout = XLSX.write(wb, {bookType: 'xlsx', bookSST: false, type: 'binary'});

  saveAs(new Blob([s2ab(wbout)], {type: "application/octet-stream"}), "test.xlsx")
}

export function export_json_to_excel({header, data, filename='excel-list', autoWidth=true}={}) {
  /* original data */
  data=[...data]
  data.unshift(header);
  var ws_name = "SheetJS";
  var wb = new Workbook(), ws = sheet_from_array_of_arrays(data);

  if(autoWidth){
    /*设置worksheet每列的最大宽度*/
    const colWidth = data.map(row => row.map(val => {
      /*先判断是否为null/undefined*/
      if (val == null) {
        return {'wch': 10};
      }
      /*再判断是否为中文*/
      else if (val.toString().charCodeAt(0) > 255) {
        return {'wch': val.toString().length * 2};
      } else {
        return {'wch': val.toString().length};
      }
    }))
    /*以第一行为初始值*/
    let result = colWidth[0];
    for (let i = 1; i < colWidth.length; i++) {
      for (let j = 0; j < colWidth[i].length; j++) {
        if (result[j]['wch'] < colWidth[i][j]['wch']) {
          result[j]['wch'] = colWidth[i][j]['wch'];
        }
      }
    }
    ws['!cols'] = result;
  }

  /* add worksheet to workbook */
  wb.SheetNames.push(ws_name);
  wb.Sheets[ws_name] = ws;

  var wbout = XLSX.write(wb, {bookType: 'xlsx', bookSST: false, type: 'binary'});
  saveAs(new Blob([s2ab(wbout)], {type: "application/octet-stream"}), filename + ".xlsx");
}

在utils下建一个公共的导出js，代码也整理好了

/*
* @method 表格数据导出excel
* @param {object} option 参数配置
*   @params {array} tHeader 表头文字 默认 []
*   @params {array} filterVal 对应字段名 默认 []
*   @params {array} table 表格数据 默认 []
*   @params {string} fileName 导出excel文件名 默认 excel-file
* @param {function} 导出成功回调
* */

const formatJson = (filterVal, jsonData) => {
  return jsonData.map(v => filterVal.map(j => v[j]))
}

export const exportFile = (option = {}, cb) => {
  import('@/vendor/Export2Excel').then(excel => {
    const tHeader = option.tHeader || [] // 对应表格输出的title
    console.log(tHeader);
    const filterVal = option.filterVal || []
    const table = option.table || []
    const data = formatJson(filterVal, table)
    // const autoWidth = option.autoWidth || true //列宽是否自适应
    const autoWidth = option.autoWidth == undefined ? true : option.autoWidth //列宽是否自适应
    excel.export_json_to_excel({
      header: tHeader,
      data,
      filename: option.fileName || 'excel-file',
      autoWidth:autoWidth
    })
    cb && cb()
  })
}

然后在vue页面加导出按钮

<el-button size="mini" icon="el-icon-download" type="primary" @click="exportData" :loading="exportLoading">导出</el-button>

引入

  import { exportFile } from "@/utils/exportExcel"; //导出
  import moment from 'moment';

在data加

exportLoading:false

在methods里

//导出
      exportData(){
        this.exportLoading = true
        let list = [
          {dogNo:2,dogName:"阿花",dogAge:28},
          {dogNo:3,dogName:"阿花1",dogAge:3},
          {dogNo:4,dogName:"阿花2",dogAge:5},
          {dogNo:5,dogName:"阿花3",dogAge:9},
        ]
        console.log(list)
        this.exportExcel(list)
      },
      exportExcel(table) {  //导出模板和参数列名
        const option = {
          tHeader: [
            "狗编号",
            "狗名称",
            "狗年龄",
          ],
          filterVal: [
            "dogNo",
            "dogName",
            "dogAge",
          ],
          table: table,
          fileName: "狗" + moment().format('YYYY-MM-DD HH_mm_ss')
        };
        exportFile(option, () => {
          this.exportLoading = false;
        });
      },

浏览器效果：

后端代码实现在浏览器导出excel（导出）

新建一个springboot项目，用mybatisplus先搭好框架。
然后添加依赖

        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.6</version>
        </dependency>

这里我把核心代码都放到controller上写，其它的都是spring boot + mybatisPlus的简单的搭建

package com.cjw.cjwExport.contoller;

import com.cjw.cjwExport.model.Student;
import com.cjw.cjwExport.service.ExportService;
import org.apache.poi.hssf.usermodel.*;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletResponse;
import java.io.OutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;

@RestController
@RequestMapping("/Export")
public class ExportController {

    @Autowired
    private ExportService exportService;

    @RequestMapping("/test01")
    @GetMapping
    public void exportTest01(HttpServletResponse response){
        exportService.exportTest01();
        System.out.println("=====export====");

        List<Student> list = exportService.list();   //做一个简单的查询

        // Excel标题
        String[] title = {"id", "课程id", "标题", "课本","时间"};
        // Excel文件名
        String fileName =  "测试.xls";
        // sheet名
        String sheetName = "测试1";
        // 将数据放到数组中
        String[][] content = new String[list.size()][title.length];
        for (int i = 0; i < list.size(); i++) {
            Date date = new Date();
            SimpleDateFormat dateFormat = new SimpleDateFormat("y-M-d H:m:s");
            String format = dateFormat.format(date);
            Student monthReportModel = list.get(i);
            content[i][0] = monthReportModel.getId();
            content[i][1] = monthReportModel.getCourseId();
            content[i][2] = monthReportModel.getTitle();
            content[i][3] = monthReportModel.getSort().toString();
            content[i][4] = format;
        }
        // 导出Excel
        try {
            HSSFWorkbook hssfWorkbook = getHSSFWorkbook(sheetName, title, content, null);
            fileName = new String(fileName.getBytes(), "ISO8859-1");
            response.setContentType("application/octet-stream;charset=ISO8859-1");
            response.setHeader("Content-Disposition", "attachment;filename=" + fileName);
            response.addHeader("Pargam", "no-cache");
            response.addHeader("Cache-Control", "no-cache");

            OutputStream outputStream = response.getOutputStream();
            hssfWorkbook.write(outputStream);
            outputStream.flush();
            outputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }



    public HSSFWorkbook getHSSFWorkbook(String sheetName, String[] title, String[][] values, HSSFWorkbook workbook) {
        // 创建一个HSSFWorkbook，对应一个Excel文件
        if (workbook == null) {
            workbook = new HSSFWorkbook();
        }
        // 在workbook中添加一个sheet,对应Excel文件中的sheet
        HSSFSheet sheet = workbook.createSheet(sheetName);
        // 在sheet中添加表头第0行
        HSSFRow row = sheet.createRow(0);
        // 创建单元格，并设置值表头 设置表头居中
        HSSFCellStyle cellStyle = workbook.createCellStyle();
        cellStyle.setAlignment(HSSFCellStyle.ALIGN_CENTER);
        // 声明列对象
        HSSFCell cell = null;
        // 创建标题
        for (int i = 0; i < title.length; i++) {
            cell = row.createCell(i);
            cell.setCellValue(title[i]);
            cell.setCellStyle(cellStyle);
        }
        // 创建内容
        for (int i = 0; i < values.length; i++) {
            row = sheet.createRow(i + 1);
            for (int j = 0; j < values[i].length; j++) {
                // 将内容按顺序赋给对应的列对象
                row.createCell(j).setCellValue(values[i][j]);
            }
        }
        return workbook;

    }


}

在浏览器输入地址测试：

结果：