java设置导出excel 普通 分页预览 java导出excel到浏览器

目录结构

• Ⅰ、导入

• 一、前端

• 1.input file
• 2.button

• 二、后端

• 1.Controller
• 2.Service
• 3.解析类ExcelUtils
• 4.👉工具类ExcelUtils👈
• 5.Mapper

• Ⅱ、导出

• 一、前端

• 1.方式一
• 2.方式二

• 二、后端

• 1.Controller
• 2.Service
• 3.Mapper

Ⅰ、导入

给到两种导入，大差不差的

一、前端

1.input file

注意1：enctype=“multipart/form-data”，method=“post”
注意2：name=“planImport”，file的name要与java读取流时的名字相同

<!--导入-->
<form action="/plan/import" enctype="multipart/form-data" method="post" id="import">
	<input type="file" name="planImport"/>
	<input type="submit" value="导入"/>
</form>

2.button

1）隐藏file
2）点击“导入”按钮，触发file点击事件；
3）file改动时，触发ajax

JS

//点击导入，✔
$("#maintain_manage_jButton5").click(function () {
	$("#file").click();//选择文件
	$("#file").change(function () {
		//创建foemdata对象
		var formData = new FormData();
		//为file赋值
		formData.append('file',$('#file')[0].files[0]);
		$.ajax({
			url : '/maintain/importExcel',
			type : 'POST',
			data : formData,
			contentType: false,// 当有文件要上传时，此项是必须的，否则后台无法识别文件流的起始位置
			processData: false,// 是否序列化data属性，默认true(注意：false时type必须是post)
			dataType: 'json',//这里是返回类型，一般是json,text等
			clearForm: true,//提交后是否清空表单数据
			success : function (data) {
				alert(data.msg);
				if(data.code == 200) {
					location.href = "/am/maintainManage";
				}
			},error : function (data,status,e) {
				console.error(e);
			}
		});
	});
});

HTML

<!--隐藏文件-->
<input type="file" name="file" id="file" style="display: none"/>
<!--别看我写的这么多，这就是一个button即可-->
<div id="maintain_manage_jButton5" class="vjbutton vjbutton_c_style2 border_radius_3">
	<div class="vjbutton_txtR">
		<span class="btniconcum1">
			<img src="../static/images/jexcel.png" width="16" height="16"/>
		</span>
		<span class="btniconcum2">
			<img src="../static/images/jexcel.png" width="16" height="16"/>
		</span>
		<span class="btntxt"></span>
		导入Excel
	</div>
</div>

二、后端

建议不要循环访问数据库，自个优化

1.Controller

/**
   * 计划导入
   */
  @RequestMapping(value = "/import",method = RequestMethod.POST)
  public BaseResult planImport(HttpServletRequest request){
      System.out.println("计划导入------------------------入导划计");
      MultipartHttpServletRequest mreq = null;
      BaseResult br = new BaseResult();
      //判断request是否是MultipartHttpServletRequest的实例
      if(request instanceof  MultipartHttpServletRequest) {
          mreq = (MultipartHttpServletRequest) request;
          //计划导入
          br = planManageService.planImport(mreq);
      } else {
          br.setCode(500);
          br.setMsg("表单类型异常");
      }
      return br;
  }

2.Service

注意解析文件那一步即可，其余步骤是在做数据处理

/**
   * 计划导入
   * @param mreq
   * @return
   */
  @Override
  public BaseResult planImport(MultipartHttpServletRequest mreq) {
      List<TbWeeklyPlan> list = null;
      BaseResult br = new BaseResult();
      try {
          //解析文件!!!!!!!!!!!!!!!!!!!!!!!!!! here
          list = ExcelUtils.analysisFileOne(mreq);
          if(list == null || list.size() == 0){
              br.setCode(500);
              br.setMsg("表单类型异常或数据异常");
              System.out.println(br.getMsg());
              return br;
          } else {
              int count = 0;//记录重复行数
              int sum = 0;//记录添加行数
              int updaSum = 0;//记录修改行数
              TbWeeklyPlan weeklyPlan;//用于判断是否完全一致
              for (TbWeeklyPlan wp : list) {
                  //建议不要多次访问数据库！！！这里直观一点
                  weeklyPlan = planManageMapper.selectPlan(wp);
                  if(weeklyPlan != null) {
                      if(StringUtils.equals(wp.getPlanYear(),weeklyPlan.getPlanYear())
                              && StringUtils.equals(wp.getSerialNumber(),weeklyPlan.getSerialNumber())
                              && StringUtils.equals(wp.getRegion(),weeklyPlan.getRegion())
                      ) {//如果完全一致，当作重复
                          count ++;
                          continue;
                      } else {//否则当作修改
                          wp.setUpdateTime(new Date());
                          wp.setUpdatePerson(SecurityContextHolder.getContext().getAuthentication().getName());
                          updaSum += planManageMapper.updatePlansById(wp);
                          continue;
                      }
                  }
                  wp.setCreateTime(new Date());
                  wp.setCreatePerson(SecurityContextHolder.getContext().getAuthentication().getName());
                  //导入数据库
                  sum += planManageMapper.planImport(wp);
              }
              String str = "成功导入 " + sum + " 条数据，" +
                      (updaSum == 0 ? "" : "成功修改" + updaSum + "条数据，") +
                      "有 " + count + " 条重复数据，不可导入!";
              System.out.println(str);
              br.setCode(200);
              br.setMsg(str);
              return br;
          }
      } catch (Exception e){
          e.printStackTrace();
          br.setCode(500);
          br.setMsg(e.getMessage());
          return br;
      }
  }

3.解析类ExcelUtils

给到浅显的两种方式（表头，列顺序），整理一下就是一个可以复用的工具类了，见》》》4.工具类ExcelUtils

package com.***.util;

import com.***.pojo.TbMaintain;
import com.***.pojo.TbWeeklyPlan;
import org.apache.poi.ss.usermodel.*;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.web.multipart.MultipartHttpServletRequest;

import java.io.IOException;
import java.io.InputStream;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.*;

/**
 * @ClassName ExcelUtils
 * @Description Excel处理工具类
 * @Author HBW
 * @Date 2021/8/30 14:32
 * @Version 1.0
 */
public class ExcelUtils {

    /**
     * 解析计划Excel
     * @param mreq
     * @return
     */
    public static List<TbWeeklyPlan> analysisFileOne(MultipartHttpServletRequest mreq)throws Exception{
        InputStream inputStream= null;
        try {
            inputStream = mreq.getFile ("planImport").getInputStream ();
        } catch (IOException e) {
            throw e;
        }
        String fileName = mreq.getFile ("planImport").getOriginalFilename ();
        Workbook workbook = null;
        try {
            //判断什么类型文件
            if (fileName.endsWith(".xls") || fileName.endsWith(".xlsx")) {
                workbook = WorkbookFactory.create(inputStream);
            } else {
                return null;
            }
        } catch (Exception e) {
            throw e;
        }
        //获取所有的工作表的的数量
        int numOfSheet = workbook.getNumberOfSheets ();
        System.out.println ("Sheet数量------------->" + numOfSheet);
        List<TbWeeklyPlan> list = new ArrayList<> ();
        //遍历表
        for (int i = 0; i < numOfSheet; i++) {//第i行
            //获取第i个sheet
            Sheet sheet = workbook.getSheetAt (i);
            if (sheet == null) {
                continue;
            }
            //获取当前sheet有多少Row
            int lastRowNum = sheet.getLastRowNum ();
            if (lastRowNum == 0) {
                continue;
            }
            Row row;
            // 行头
            List<String> headName = new ArrayList<>();
            if(lastRowNum>0){
                row = sheet.getRow (0);
                // 获取一个Row有多少Cell
                short lastCellNum = row.getLastCellNum ();
                if(lastCellNum < 3){//浅显的判断，看自己的需求
                    System.out.println("表头异常");
                    return null;
                }
                for (int k = 0; k <= lastCellNum; k++) {
                    if (row.getCell (k) == null) {
                        continue;
                    }
                    String res = getCellVal(row.getCell (k));
                    headName.add (res);
                }
            }

            // 每一行的内容
            //保存weeks，下一行weeks为空时，用此填充
            String weeks = null;
            for (int j = 1; j <= lastRowNum; j++) {
                row = sheet.getRow (j);
                if (row == null) {
                    continue;
                }
                //获取一个Row有多少Cell
                short lastCellNum = row.getLastCellNum ();
                TbWeeklyPlan weeklyPlan = new TbWeeklyPlan();
                for (int k = 0; k <= lastCellNum; k++) {
                    try {
                        if (row.getCell (k) == null) {
                            continue;
                        }
                        String res = getCellVal(row.getCell (k));
                        switch (headName.get(k)){
                            case "年份" :
                                weeklyPlan.setPlanYear(res);
                                break;
                            case "周次" :
                                weeklyPlan.setWeeks(res.contains("WW") ? res : "WW" + res);
                                break;
                            case "区域" :
                                weeklyPlan.setRegion(res);
                                break;
                            default:
                                return null;
                        }
                    } catch (Exception e){
                        e.printStackTrace();
                        return null;
                    }
                }
                list.add (weeklyPlan);
            }
            System.out.println("共有：" + lastRowNum + "条数据");
        }
        return list;
    }

    /**
     * 解析来料Excel
     * @param mreq
     * @return
     * @throws Exception
     */
    public static List<TbMaintain> analysisFileTwo(MultipartHttpServletRequest mreq) throws Exception {
        InputStream inputStream= null;
        try {
            inputStream = mreq.getFile ("file").getInputStream ();
        } catch (IOException e) {
            throw e;
        }
        String fileName = mreq.getFile ("file").getOriginalFilename ();
        Workbook workbook = null;
        try {
            //判断什么类型文件
            if (fileName.endsWith(".xls") || fileName.endsWith(".xlsx")) {
                workbook = WorkbookFactory.create(inputStream);
            } else {
                return null;
            }
        } catch (Exception e) {
            throw e;
        }
        //获取所有的工作表的的数量
        int numOfSheet = workbook.getNumberOfSheets ();
        System.out.println ("Sheet数量------------->" + numOfSheet);
        List<TbMaintain> list = new ArrayList<> ();
        //遍历表
        for (int i = 0; i < numOfSheet; i++) {//第i行
            //获取第i个sheet
            Sheet sheet = workbook.getSheetAt (i);
            if (sheet == null) {
                continue;
            }
            //获取当前sheet有多少Row
            int lastRowNum = sheet.getLastRowNum ();
            if (lastRowNum == 0) {
                continue;
            }
            Row row;
            // 行头
            List<String> headName = new ArrayList<>();
            if(lastRowNum>0){
                row = sheet.getRow (0);
                // 获取一个Row有多少Cell
                short lastCellNum = row.getLastCellNum ();
                for (int k = 0; k <= lastCellNum; k++) {
                    if (row.getCell (k) == null) {
                        continue;
                    }
                    String res = getCellVal(row.getCell (k));
                    headName.add (res);
                }
            }

            // 每一行的内容，跳过表头
            for (int j = 1; j <= lastRowNum; j++) {
                row = sheet.getRow (j);
                if (row == null) {
                    continue;
                }
                //获取一个Row有多少Cell
                short lastCellNum = row.getLastCellNum ();
                TbMaintain tm = new TbMaintain();
                tm.setCreateTime(new Date());
                tm.setCreatePerson(SecurityContextHolder.getContext().getAuthentication().getName());
                for (int k = 0; k <= lastCellNum; k++) {
                    try {
                        if (row.getCell (k) == null) {
                            continue;
                        }
                        String res = getCellVal(row.getCell (k));
                        switch (k){
                            case 0 :
                                tm.setSendSamplePerson(res);
                                break;
                            case 1 :
                                tm.setSendSampleDate(res);
                                break;
                            case 2 :
                                tm.setItemNo(res);
                                break;
                            default://异常
                                return null;
                        }
                    } catch (Exception e){
                        e.printStackTrace();
                        return null;
                    }
                }
                list.add (tm);
            }
            System.out.println("共有：" + lastRowNum + "条数据");
        }
        return list;
    }

	/**
     * 单元格类型处理
     * @param cell
     * @return 转为String
     */
    private static String getCellVal(Cell cell) {
        if(cell == null){
            return null;
        }
        SimpleDateFormat fmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); //日期格式yyyy-mm-dd
        DecimalFormat df = new DecimalFormat("0");
        String val;
        switch (cell.getCellType()) {
            case Cell.CELL_TYPE_NUMERIC:
                if (DateUtil.isCellDateFormatted(cell)) {
                    val = fmt.format(cell.getDateCellValue()); //日期型
                } else {
                    val = df.format(cell.getNumericCellValue()); //数字型
                }
                break;
            case Cell.CELL_TYPE_STRING: //文本类型
                val = cell.getStringCellValue();
                break;
            case Cell.CELL_TYPE_BOOLEAN: //布尔型
                val = String.valueOf(cell.getBooleanCellValue());
                break;
            case Cell.CELL_TYPE_BLANK: //空白
                val = cell.getStringCellValue();
                break;
            case Cell.CELL_TYPE_ERROR: //错误
                val = "错误";
                break;
            case Cell.CELL_TYPE_FORMULA: //公式
                try {
                    val = String.valueOf(cell.getStringCellValue());
                } catch (IllegalStateException e) {
                    val = String.valueOf(cell.getNumericCellValue());
                }
                break;
            default:
                val = cell.getRichStringCellValue() == null ? null : cell.getRichStringCellValue().toString();
        }
        return val;
    }
}

4.👉工具类ExcelUtils👈

为了复用嘛，特此整理了一下

import org.apache.poi.ss.usermodel.*;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.web.multipart.MultipartHttpServletRequest;

import java.io.IOException;
import java.io.InputStream;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.*;

/**
 * @ClassName ExcelUtils
 * @Description Excel工具类
 * @Author HBW
 * @Date 2021/7/8 14:32
 * @Version 1.0
 */
public class ExcelUtils {

    /**
     * 解析Excel
     * @param mreq
     * @return
     * @throws Exception
     */
    public static Set<Object[]> analysisFile(MultipartHttpServletRequest mreq) throws Exception {
        InputStream inputStream= null;
        Set<Object[]> set = new HashSet<>();
        try {
            inputStream = mreq.getFile("file").getInputStream();
            String fileName = mreq.getFile("file").getOriginalFilename();
            Workbook workbook = null;
            //判断什么类型文件
            if (fileName.endsWith(".xls") || fileName.endsWith(".xlsx")) {
                workbook = WorkbookFactory.create(inputStream);
            } else {
                return null;
            }
            //获取所有的工作表的的数量
            int numOfSheet = workbook.getNumberOfSheets();
            System.out.println("Sheet数量------------->" + numOfSheet);

            //遍历表
            for (int i = 0; i < numOfSheet; i++) {//第i行
                //获取第i个sheet
                Sheet sheet = workbook.getSheetAt(i);
                if (sheet == null) {
                    continue;
                }
                //获取当前sheet有多少Row
                int lastRowNum = sheet.getLastRowNum();
                if (lastRowNum == 0) {
                    continue;
                }
                Row row;

                // 内容：每一行的内容，跳过表头(j = 1)
                for (int j = 1; j <= lastRowNum; j++) {
                    row = sheet.getRow(j);
                    if (row == null) {
                        continue;
                    }
                    //获取一个Row有多少Cell
                    short lastCellNum = row.getLastCellNum();
                    Object[] obj = new Object[lastCellNum + 2];
                    for (int k = 0; k <= lastCellNum; k++) {
                        if (row.getCell(k) == null) {
                            continue;
                        }
                        String res = getCellVal(row.getCell(k));
                        obj[k] = res;
                    }
                    obj[22] = new Date();
                    obj[23] = SecurityContextHolder.getContext().getAuthentication().getName();
                    set.add(obj);
                }
                System.out.println("共有：" + (lastRowNum - 1) + "条数据");
            }
        } catch (Exception e){
            throw e;
        }
        return set;
    }
    
    private static String getCellVal(Cell cell) {
        if(cell == null){
            return null;
        }
        SimpleDateFormat fmt = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); //日期格式yyyy-mm-dd
        DecimalFormat df = new DecimalFormat("0");
        String val;
        switch (cell.getCellType()) {
            case Cell.CELL_TYPE_NUMERIC:
                if (DateUtil.isCellDateFormatted(cell)) {
                    val = fmt.format(cell.getDateCellValue()); //日期型
                } else {
                    val = df.format(cell.getNumericCellValue()); //数字型
                }
                break;
            case Cell.CELL_TYPE_STRING: //文本类型
                val = cell.getStringCellValue();
                break;
            case Cell.CELL_TYPE_BOOLEAN: //布尔型
                val = String.valueOf(cell.getBooleanCellValue());
                break;
            case Cell.CELL_TYPE_BLANK: //空白
                val = cell.getStringCellValue();
                break;
            case Cell.CELL_TYPE_ERROR: //错误
                val = "错误";
                break;
            case Cell.CELL_TYPE_FORMULA: //公式
                try {
                    val = String.valueOf(cell.getStringCellValue());
                } catch (IllegalStateException e) {
                    cell.setCellType(Cell.CELL_TYPE_STRING);
                    val = cell.getStringCellValue();
//                    val = String.valueOf(cell.getNumericCellValue());
                }
                break;
            default:
                val = cell.getRichStringCellValue() == null ? null : cell.getRichStringCellValue().toString();
        }
        return val;
    }

}

5.Mapper

与数据库交互，巴拉巴拉。

<insert id="importExcel" parameterType="list">
    INSERT INTO tb_maintain
        (
            send_sample_person,
            send_sample_date,
            item_no
        )
        VALUES
        <foreach collection="list" item="item" index="index" separator=",">
            (
                #{item.sendSamplePerson},
                #{item.sendSampleDate},
                #{item.itemNo}
            )
        </foreach>
</insert>

Ⅱ、导出

查询数据库某些记录，（生成本地临时文件），再以浏览器的形式下载

一、前端

1.方式一

JS

//导出数据
$("#plan_manage_jButton4").click(function () {
	//1.拿到勾选数据的ID
	var ids = new Array();//保存勾选的id(数据库ID)
	var selectIds = new Array();//保存勾选的id(索引id)
	var flag1 = false;
	var flag2 = false;
	getIds(ids,selectIds);//获取勾选数据的id
	//2.判断
	if(ids.length == 0){
		flag1 = confirm("未勾选数据，是否导出模板？");
	} else {
		flag2 = confirm("是否导出，勾选的 " + ids.length + " 条数据？");
	}
	//3.正式开始
	if(flag1 || flag2){
		//1.创建XMLHttpRequest组建
		//2.设置回调函数
		//3.初始化XMLHttpRequest组建
		//4.发送请求
		//区别：get路径传参；post设置请求头，send处传参
		var xhr = new XMLHttpRequest();
		xhr.open('GET','/plan/export?keys=' + ids.toString(),true);//get请求、请求路径、是否异步
		xhr.responseType = "blob";//返回类型blob
		xhr.onload = function () {//请求完成处理函数
			if(this.status == 200){
				var blob = this.response;//获取返回值
				var a = document.createElement('a');
				a.download = "计划表" + new Date().toLocaleDateString() + ".xlsx";
				a.href = window.URL.createObjectURL(blob);
				a.click();
			}
		};
		//发送ajax请求
		xhr.send();
		//取消勾选
		for (var i = 0; i < selectIds.length; i++) {
            $("tr[id='" + selectIds[i] + "'] td:eq(0) input").prop("checked",false);
		}
	}
});

HTML

<!--一个button即可-->
<div id="plan_manage_jButton4" class="vjbutton vjbutton_c_style2 border_radius_3">
	<div class="vjbutton_txtR">
		<span class="btniconcum1">
			<img src="../static/images/jexcel.png" width="16" height="16"/>
		</span>
		<span class="btniconcum2">
			<img src="../static/images/jexcel.png" width="16" height="16"/>
		</span>
		<span class="btntxt"></span>
		导出Excel
	</div>
</div>

2.方式二

就一个button按钮，跳转时想办法把数据带过去即可；不带数据，下载全表数据，下方这般操作即可：

<!--导出-->
<input type="button" name="planExport" value="导出" onclick="location='/plan/export'"/>

二、后端

以流的方式在本地生成Excel，再以浏览器的方式打开【经常使用，搞成工具类就好】

1.Controller

浏览器打开本地临时Excel，完成下载动作

/**
   * 计划导出
   * @param keys 被勾选数据的ID
   * @param response
   */
  @RequestMapping("/export")
  public void planExport(String keys,HttpServletResponse response){
      System.out.println("计划导出------------------------出导划计");
      Date date=new Date();
      DateFormat format=new SimpleDateFormat("yyyyMMdd");
      String fileName = "计划表" + format.format(date) + ".xlsx";
      //清空response
      response.reset();
      //让浏览器下载文件,fileName是上述默认文件下载名
      response.setContentType("application/vnd.ms-excel;charset=utf-8");
      //设置response的Header
      try {
          //header仍是乱码？？？
          response.setHeader("Content-Disposition","attachment;filename=" + URLEncoder.encode(fileName,"UTF8"));
      } catch (UnsupportedEncodingException e) {
          e.printStackTrace();
      }
      response.addHeader("Cache-Control","no-cache");
      InputStream inputStream=null;
      ByteArrayOutputStream bos=null;
      //在service层中已经将数据存成了excel临时文件，并返回了临时文件的路径
      String downloadPath = planManageService.exportStu(keys,"");
      //根据临时文件路径创建文件对象
      File file = new File(downloadPath);
      try {
          inputStream = new FileInputStream(file);
          bos = new ByteArrayOutputStream(1024);
          int len = -1;
          byte[] b = new byte[1024];
          while((len = inputStream.read(b)) != -1){
              bos.write(b,0,len);
          }
          response.getOutputStream().write(bos.toByteArray());
          //刷新
          bos.flush();
      } catch (FileNotFoundException e) {
          e.printStackTrace();
      } catch (IOException e) {
          e.printStackTrace();
      } finally {
          //关闭流
          try {
              if(inputStream != null) {
                  inputStream.close();
              }
              if(bos != null) {
                  bos.close();
              }
          } catch (IOException e) {
              e.printStackTrace();
          }
      }
      //删除临时文件
      file.delete();
  }

2.Service

以流的形式在本地生成临时Excel

/**
   * 导出数据库数据到本地
   * @return
   */
  @Override
  public String exportStu(String keys) {
      //计划列表
  	  List<TbWeeklyPlan> list = null;
      //创建工作簿
      XSSFWorkbook xssfWorkbook = new XSSFWorkbook();
      //创建工作表
      XSSFSheet sheet = xssfWorkbook.createSheet();
      xssfWorkbook.setSheetName(0,"计划表");
      //创建表头
      XSSFRow head = sheet.createRow(0);
      String[] heads = {"年份","周次","区域"};
      for(int i = 0;i < heads.length;i++){
          XSSFCell cell = head.createCell(i);
          cell.setCellValue(heads[i]);
      }

      if(!"".equals(keys) && keys != null) {//导出勾选部分
          List<String> keyList = Arrays.asList(keys.split(","));
          list = planManageMapper.selectPlanKeys(keyList);
      } else {//导出模板
          list = null;
      }

      //内容填充，除导出模板、未查到数据不需要
      if(list!=null && list.size()>0){
          for(int i = 1 ; i<=list.size() ; i++) {
              TbWeeklyPlan weeklyPlan = list.get(i-1);
              //创建行，从第二行开始（i=1）
              XSSFRow row = sheet.createRow(i);
              //创建单元格，并填充数据
              XSSFCell cell = row.createCell(0);
              cell.setCellValue(weeklyPlan.getPlanYear());

              cell = row.createCell(1);
              cell.setCellValue(weeklyPlan.getWeeks());

              cell = row.createCell(2);
              cell.setCellValue(weeklyPlan.getRegion());
          }
      }

      //创建文件目录
      File file = new File(customPath.getXls());//你给个路径就行，比如：C:\\Users\\Administrator\\Desktop\\xls\\
      if(!file.exists()) {
          file.mkdirs();
      }

      //导出名称
      String fileName = "计划表.xlsx";
      
      //导出路径
      String exportPath = file + "\\" + fileName;
      OutputStream outputStream = null;
      try {
          outputStream = new FileOutputStream(exportPath);
          xssfWorkbook.write(outputStream);
          outputStream.flush();
      } catch (FileNotFoundException e) {
          e.printStackTrace();
      } catch (IOException e) {
          e.printStackTrace();
      } finally {
          try {
              if(outputStream != null) {
                  outputStream.close();
              }
          } catch (IOException e) {
              e.printStackTrace();
          }
      }
      
      System.out.println("导出数据：" + (list != null && list.size()>0 ? list.size() : 0) + "条");
      System.out.println("导出路径" + exportPath);
      return exportPath;
  }

3.Mapper

查数据库~

<select id="selectMaintainKeys" parameterType="list" resultMap="tmr">
    SELECT
    id,send_sample_person,send_sample_date,item_no,
    DATE_FORMAT(create_time,'%Y-%m-%d %H:%i:%s') AS create_time,
    create_person,
    DATE_FORMAT(update_time,'%Y-%m-%d %H:%i:%s') AS update_time,
    update_person
    FROM tb_maintain
    WHERE id IN
    <foreach collection="keyList" item="id" index="index" separator="," open="(" close=")">
        #{id}
    </foreach>
</select>