java数据库数据导入excel

data导出入excel中

controller：

package com.longfor.hrssc.api.controller;

import com.longfor.hrssc.api.model.BasicInformation;
import com.longfor.hrssc.api.service.IBasicInformationService;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

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

/**
 * Created by fmgao on 2019/5/5.
 */
@RestController
@RequestMapping("/export")
public class ExportExcel {
    @Autowired
    private IBasicInformationService basicInformationService;

    @RequestMapping(value = "/excel", method = RequestMethod.GET)
    public Object excel2(HttpServletResponse response) throws Exception {
//        list = getUsers();
        String columnName = "t_basic_information";
        BasicInformation basicInformation = new BasicInformation();
        basicInformation.setTableName(columnName);
        List<String> titles = new ArrayList();
        titles = basicInformationService.getColumnNames(basicInformation);
        System.out.println(titles);
        List<BasicInformation> list = new ArrayList();
        list = basicInformationService.getAllDatas(basicInformation);

        stuList2Excel(list,titles);
        return null;
    }

    /**
     * @param stuList 从数据库中查询需要导入excel文件的信息列表
     * @return 返回生成的excel文件的路径
     * @throws Exception
     */
    public static String stuList2Excel(List<BasicInformation> stuList,List<String> titles) throws Exception {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd");
        SimpleDateFormat sdf1 = new SimpleDateFormat("yyyyMMdd hhmmss");
        Workbook wb = new XSSFWorkbook();
        //标题行抽出字段
//        String[] title = titles;
        //设置sheet名称，并创建新的sheet对象
        String sheetName = "学生信息一览";
        Sheet stuSheet = wb.createSheet(sheetName);
        //获取表头行
        Row titleRow = stuSheet.createRow(0);
        //创建单元格，设置style居中，字体，单元格大小等
        CellStyle style = wb.createCellStyle();
        Cell cell = null;
        //把已经写好的标题行写入excel文件中
        for (int i = 0; i < titles.size(); i++) {
            cell = titleRow.createCell(i);
            cell.setCellValue(titles.get(i));
            cell.setCellStyle(style);
        }
        //把从数据库中取得的数据一一写入excel文件中
        Row row = null;
        for (int i = 0; i < stuList.size(); i++) {
            //创建list.size()行数据
            row = stuSheet.createRow(i + 1);
            //把值一一写进单元格里
            //设置第一列为自动递增的序号
//            row.createCell(0).setCellValue(i + 1);
            row.createCell(0).setCellValue(stuList.get(i).getId());
            row.createCell(1).setCellValue(stuList.get(i).getBasicCode());
            row.createCell(2).setCellValue(stuList.get(i).getBasicName());
            row.createCell(3).setCellValue(stuList.get(i).getBasicType());
            row.createCell(4).setCellValue(stuList.get(i).getBasicPid());
            row.createCell(5).setCellValue(stuList.get(i).getIsDelete());
            row.createCell(6).setCellValue(stuList.get(i).getCreateUserId());
            //把时间转换为指定格式的字符串再写入excel文件中
            if (stuList.get(i).getCreateTime() != null) {
                row.createCell(7).setCellValue(sdf.format(stuList.get(i).getCreateTime()));
            }
            if (stuList.get(i).getUpdateTime() != null) {
                row.createCell(8).setCellValue(sdf.format(stuList.get(i).getUpdateTime()));
            }

        }
        //设置单元格宽度自适应，在此基础上把宽度调至1.5倍
        for (int i = 0; i < titles.size(); i++) {
            stuSheet.autoSizeColumn(i, true);
            stuSheet.setColumnWidth(i, stuSheet.getColumnWidth(i) * 15 / 10);
        }
        //获取配置文件中保存对应excel文件的路径，本地也可以直接写成F：excel/stuInfoExcel路径
//        String folderPath = ResourceBundle.getBundle("systemconfig").getString("downloadFolder") + File.separator + "stuInfoExcel";
        String folderPath = "F:\\file_soft\\me\\excel\\";
        //创建上传文件目录
        File folder = new File(folderPath);
        //如果文件夹不存在创建对应的文件夹
        if (!folder.exists()) {
            folder.mkdirs();
        }
        //设置文件名
        String fileName = sdf1.format(new Date()) + sheetName + ".xlsx";
        String savePath = folderPath + File.separator + fileName;
        // System.out.println(savePath);

        OutputStream fileOut = new FileOutputStream(savePath);
        wb.write(fileOut);
        fileOut.close();
        //返回文件保存全路径
        System.out.println(savePath);
        return savePath;
    }
}

sevice：

/**
     * 获取所有的列
     * @param basicInformation
     * @return
     */
    public List<String> getColumnNames(BasicInformation basicInformation){
        List<String> names = basicInformationMapper.getColumnNames(basicInformation);
        return names;
    }

    /**
     * 获取所有的数据
     * @param basicInformation
     * @return
     */
    public List<BasicInformation> getAllDatas(BasicInformation basicInformation){
        List<BasicInformation> list = basicInformationMapper.getAllDatas(basicInformation);
        return list;
    }

dao:

    List<String> getColumnNames(BasicInformation basicInformation);

    List<BasicInformation> getAllDatas(BasicInformation basicInformation);

xml：

<!--getColumnNames-->
<select id="getColumnNames" resultType="java.lang.String"
        parameterType="com.longfor.hrssc.api.model.BasicInformation">
    select DISTINCT COLUMN_NAME from information_schema.COLUMNS where table_name=#{tableName}
</select>

<!--get all-->
<select id="getAllDatas" resultMap="BaseResultMap"
        parameterType="com.longfor.hrssc.api.model.BasicInformation">
    select * from t_basic_information;
</select>

pom:

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.1.0</version>
</dependency>

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi</artifactId>
    <version>3.16</version>
</dependency>
<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>3.16</version>
</dependency>

原文地址：https://www.cnblogs.com/fmgao-technology/p/10821245.html