java:将excel导出为json

方法一：

最常见的是用poi

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>3.17</version>
</dependency>

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.17</version>
</dependency>

/**
 * 表格处理工具类
 *
 * @author luc
 * @date 2020/8/515:52
 */
@Slf4j
public class ExcelUtils {

    public static void main(String[] args) {
        try {
            FileInputStream inp = new FileInputStream("D://统计表.xlsx");
            Workbook workbook = WorkbookFactory.create(inp);
            //获取sheet数
            int sheetNum = workbook.getNumberOfSheets();
            JSONObject jsonObject = new JSONObject();
            for (int s = 0; s < sheetNum; s++) {
                // Get the Sheet of s.
                Sheet sheet = workbook.getSheetAt(s);
                //获取最大行数
                int rownum = sheet.getPhysicalNumberOfRows();
                if (rownum <= 1) {
                    continue;
                }
                //获取第一行
                Row row1 = sheet.getRow(0);
                //获取最大列数
                int colnum = row1.getPhysicalNumberOfCells();
                JSONArray jsonArray = new JSONArray();
                for (int i = 1; i < rownum; i++) {
                    Row row = sheet.getRow(i);
                    if (row != null) {
//                    List<Object> list = new ArrayList<>();
                        JSONObject rowObj = new JSONObject();
                        //循环列
                        for (int j = 0; j < colnum; j++) {
                            Cell cellData = row.getCell(j);
                            if (cellData != null) {
                                //判断cell类型
                                switch (cellData.getCellType()) {
                                    case Cell.CELL_TYPE_NUMERIC: {
                                        rowObj.put(row1.getCell(j).getStringCellValue(), cellData.getNumericCellValue());
                                        break;
                                    }
                                    case Cell.CELL_TYPE_FORMULA: {
                                        //判断cell是否为日期格式
                                        if (DateUtil.isCellDateFormatted(cellData)) {
                                            //转换为日期格式YYYY-mm-dd
                                            rowObj.put(row1.getCell(j).getStringCellValue(), cellData.getDateCellValue());
                                        } else {
                                            //数字
                                            rowObj.put(row1.getCell(j).getStringCellValue(), cellData.getNumericCellValue());
                                        }
                                        break;
                                    }
                                    case Cell.CELL_TYPE_STRING: {
                                        rowObj.put(row1.getCell(j).getStringCellValue(), cellData.getStringCellValue());
                                        break;
                                    }
                                    default:
                                        rowObj.put(row1.getCell(j).getStringCellValue(), "");
                                }
                            } else {
                                rowObj.put(row1.getCell(j).getStringCellValue(), "");

                            }
                        }
                        jsonArray.add(rowObj);
                    }
                }
                System.out.println(jsonArray.toJSONString());
                jsonObject.put(sheet.getSheetName(), jsonArray);
            }
            System.out.println(jsonObject.toJSONString());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

方法二：

更好用的是用easyexcel（阿里开发的）

<!--easyexcel文件解析-->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>easyexcel</artifactId>
    <version>2.2.7</version>
</dependency>

package com.sundear.document.util;


import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.EasyExcelFactory;
import com.alibaba.excel.ExcelReader;
import com.alibaba.excel.event.SyncReadListener;
import com.alibaba.excel.read.listener.ReadListener;
import com.alibaba.fastjson.JSONObject;
import lombok.extern.slf4j.Slf4j;
import org.apache.poi.poifs.filesystem.FileMagic;
import tk.mybatis.mapper.util.Assert;


import java.io.*;
import java.util.*;

/**
 * 表格处理工具类
 *
 * @author luc
 * @date 2020/8/515:52
 */
@Slf4j
public class EasyExcelUtils {

    public static void readExcel(InputStream inStream, Class head, ReadListener listener) {
        EasyExcel.read(inStream, head, listener).sheet().doRead();
    }
    /**
     * 根据excel输入流，读取excel文件
     *
     * @param inputStream exece表格的输入流
     * @return 返回双重list的集合
     **/
    public static String writeWithoutHead(InputStream inputStream) {
        SyncReadListener listener = new SyncReadListener();
        ExcelReader excelReader = EasyExcelFactory.read(inputStream, null, listener).headRowNumber(0).build();
        excelReader.readAll();
        List<Object> list = listener.getList();
        log.info("读取结果:"+JSONObject.toJSONString(list));
        excelReader.finish();
        return JSONObject.toJSONString(list);
    }


    public static void main(String[] args) {
        String result =new String();
        try{
            FileInputStream inp = new FileInputStream("D://人口信息.xls");
            result = writeWithoutHead(inp);
        }catch (Exception e){
            e.printStackTrace();
        }
        //Assert.assertNotNull(result);

    }

}