Java 使用Apache POI读取和写入Excel表格

1,引入所用的包

 <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.5-FINAL</version>
 </dependency>

2,创建列名List,此处将显示到单元格每列名称,根据自己的业务需求更改列名

List<String> columnList = new ArrayList();
        columnList.add("申请人账号");
        columnList.add("申请人");
        columnList.add("提现金额");
        columnList.add("开户行");
        columnList.add("持卡人");
        columnList.add("卡号");
        columnList.add("银行名称");
        columnList.add("申请时间");

3,创建将要导出的参数(实体类),此处必须和创建的列名List一一对应,否则会错行显示

package com.sanmi.active.fission.management.balance.dto;

import lombok.Data;

import java.math.BigDecimal;
import java.sql.Timestamp;

/**
 * @author：Ziggo Xu <br/>
 * <p>提现管理导出参数</p>
 * ===============================
 * Date：2018/12/12
 * Time：16:55
 * ================================
 */
@Data
public class UserBalanceCashExcelDTO {
    /**
     * 申请人账户
     */
    private String account;
    /**
     * 申请人
     */
    private String nickName;
    /**
     * 提现金额
     */
    private BigDecimal bcCashMoney;/**
     * 开户行名称
     */
    private String ubiOpenBank;
    /**
     * 持卡人姓名
     */
    private String ubiRealName;
    /**
     * 银行卡卡号
     */
    private String ubiCardNo;
    /**
     * 银行卡名称
     */
    private String ubiBankName;
    /**
     * 提现时间
     */
    private Timestamp bcCreateTime;

}

4,创建导出Excel的工具类

package com.sanmi.active.fission.base.util;

import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Field;
import java.sql.Timestamp;
import java.text.SimpleDateFormat;
import java.util.*;

public class Tool {
    /**
     * 导出excel操作
     * @param response
     * @param columnList 列名
     * @param list 内容
     * @param title
     * @param titlePostion 标题位置
     * @throws IllegalAccessException
     * @throws IOException
     */
    public static void export(HttpServletResponse response, List<String> columnList, List<?> list, String title, Integer titlePostion) throws IllegalAccessException, IOException {

        response.reset();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddhhmmss");
        String dateStr = sdf.format(new Date());
        Map<String,Object> map=new HashMap<String,Object>();
        // 指定下载的文件名
        response.setHeader("Content-Disposition", "attachment;filename=" +dateStr+".xlsx");
//        response.setContentType("application/vnd.ms-excel;charset=UTF-8");

        XSSFWorkbook workBook = new XSSFWorkbook();
        // 在workbook中添加一个sheet,对应Excel文件中的sheet
        XSSFSheet sheet = workBook.createSheet();

        //列号
        int colNum = 0;
        //行号
        int rowNum = 0;
        XSSFRow rowtitle = sheet.createRow(rowNum++);
        rowtitle.createCell(titlePostion).setCellValue(title);
        XSSFRow rowheader = sheet.createRow(rowNum++);
        for(String string:columnList){
            rowheader.createCell(colNum++).setCellValue(string);
        }
        Iterator iterator = list.iterator();
        while (iterator.hasNext()){
            Object object = iterator.next();
            XSSFRow row = sheet.createRow(rowNum++);
            colNum=0;
            for (Field field : object.getClass().getDeclaredFields()){
                field.setAccessible(true);
                if (field.getType().isInstance(Timestamp.class)){
                    row.createCell(colNum++).setCellValue(field.get(object).toString()
                            .substring(0,field.get(object).toString().indexOf(".")));
                }else {
                    if(field.get(object) == null){
                        row.createCell(colNum++).setCellValue("");
                    }else {
                        row.createCell(colNum++).setCellValue(field.get(object).toString());
                    }
                }
            }
        }
        workBook.write(response.getOutputStream());
    }
}

5,业务逻辑处理,使用第三部创建的UserBalanceCashExcelDTO  接收集合参数 

 List<UserBalanceCashExcelDTO> list = balanceCashApplyService.exportApplyList(param);

6,设置文档的标题

   SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
   String title = "提现申请导出" + "(" + df.format(new Date()) + ")";

7,调用工具类,导出文档

  Tool.export(response, columnList, list, title, 1);

参考代码如下

  /**
     * 导出提现信息
     *
     * @param param
     * @throws Exception
     * @throws IllegalAccessException
     */
    @RequestMapping("/exportApplyList")
    public void exportApplyList(UserBalanceCashParam param) throws Exception {
        SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        List<UserBalanceCashExcelDTO> list = balanceCashApplyService.exportApplyList(param);
        String title = "提现申请导出" + "(" + df.format(new Date()) + ")";
        List<String> columnList = new ArrayList();
        columnList.add("申请人账号");
        columnList.add("申请人");
        columnList.add("提现金额");
        columnList.add("开户行");
        columnList.add("持卡人");
        columnList.add("卡号");
        columnList.add("银行名称");
        columnList.add("申请时间");
        //导出
        Tool.export(response, columnList, list, title, 1);
    }

导出效果图示

8,补充读取excel逻辑实现,新建存储实体

package com.sanmi.active.fission.management.balance.dto;

import lombok.Data;

import java.sql.Timestamp;

/**
 * @author：Ziggo Xu <br/>
 * <p>导出excel 实体类，与 excel列名对应</p>
 * ===============================
 * Date：2019/04/12
 * Time：16:55
 * ================================
 */
@Data
public class ExcelEntity{
    //患者id
    private String id;
    //患者名称
    private String name;
    //患者检查类型标识  CT MR US 病理
    private String flag;
    //患者报告内容
    private String content;
    //分析结果
    private String result;

}

9,补充读取excel逻辑实现,读取方法

    public static void begin(HttpServletResponse response) throws Exception {
        Workbook wb =null;
        Sheet sheet = null;
        Row row = null;
        List<Map<String,String>> list = null;
        List<ExcelEntity> entitys =  new ArrayList<ExcelEntity>();
        String cellData = null;
        //这里设置要读取的原始数据
        String filePath = "D:\\潍坊二院数据.xls";
        //此处的数据是没有意义的，只是为了读取原始数据的列数（5列），设置失误会导致缺失数据
        String columns[] = {"id","name","flag","flagName","content"};
        wb = readExcel(filePath);
        if(wb != null){
            //用来存放表中数据
            list = new ArrayList<Map<String,String>>();
            //获取第三个sheet
            sheet = wb.getSheetAt(2);
            //获取最大行数
            int rownum = sheet.getPhysicalNumberOfRows();
            //获取第一行
            row = sheet.getRow(0);
            //获取最大列数
           // int colnum = row.getPhysicalNumberOfCells();
            int colnum = 5;//暂定数据，最大五行，其他空白行无意义

            ExcelEntity entity = new ExcelEntity();
            for (int i = 1; i<rownum; i++) {
                Map<String,String> map = new LinkedHashMap<String,String>();
                row = sheet.getRow(i);
                     if(row !=null){
                         for (int j=0;j<colnum;j++){
                             cellData = (String) getCellFormatValue(row.getCell(j));
                             map.put(columns[j], cellData);
                         }
                     }else{
                         break;
                     }
                list.add(map);
                     //entitys.add(entity);
            }
        }
        //遍历解析出来的list
        for (Map<String,String> map : list) {
            String flag = null;
            String content;
            JSONArray jsonArry = null;
            String id = null;
            ExcelEntity entity = new ExcelEntity();
            for (Entry<String,String> entry : map.entrySet()) {
               // System.out.print(entry.getKey()+":"+entry.getValue()+",");
                //检查类型
                if(entry.getKey().equals("flag")) {
                     flag = entry.getValue();
                     entity.setFlag(entry.getValue());
                }
                //检查的内容
                if(entry.getKey().equals("content")) {
                    content = entry.getValue();
                    content = "[{'content':'"+content+"','pat_in_hos_id':'"+id+"','study_bodypart':'test','time':'2019-03-01 12:05:00'}]";
                    if(!EmptyUtil.isEmpty(content)) {
                     jsonArry =JSONArray.fromObject(content);
                    }
                    entity.setContent(content);
                    }
                //检查患者的Id
                if(entry.getKey().equals("id")) {
                    id = entry.getValue();
                    entity.setId(id);
                }
                //检查患者的名称
                if(entry.getKey().equals("name")) {
                    entity.setName(entry.getValue());
                }
            }
            entity.setResult("测试结果");
            entitys.add(entity);
        }
        //读取方法完成,已封装为list实体!!!!!!
        System.out.println(entitys.size());
    }