SpringBoot整合EasyExcel(完整版包含上传解析excel和下载模板)

 
      com.alibaba
      easyexcel
      2.2.7
    

@PostMapping("plUpdate")
  public R plUpdate(@RequestParam("filename") MultipartFile file) throws IOException {
    //String Originalfilename = file.getOriginalFilename();
    // String fileName = file.getName();
   // System.out.println("orname="+Originalfilename+";"+"filename"+file.getName());

    // 获取文件全名
    String fileName = file.getOriginalFilename();
     //设置文件路径
    String templatePath = "G:/excel/";
    File dest0 = new File(templatePath);
    File dest = new File(dest0, fileName);
    //文件上传-覆盖
    try {
      // 检测是否存在目录
      if (!dest0.getParentFile().exists()) {
        dest0.getParentFile().mkdirs();
        //检测文件是否存在
      }
      if (!dest.exists()) {
        dest.mkdirs();
      }
      file.transferTo(dest);
    } catch (Exception e) {
      return R.error();
    }

    String finameUrl = templatePath+fileName;
    ExcelReader excelReader = null;
    try {
    //TeacherExcel.class对应的是和模板一样的实体类，
    //eduTeacherService对应持久层的接口
      excelReader = EasyExcel.read(finameUrl, TeacherExcel.class, new DemoDataListener(eduTeacherService)).build();
      ReadSheet readSheet = EasyExcel.readSheet(0).build();
      excelReader.read(readSheet);
    } finally {

      if (excelReader != null) {
        // 这里千万别忘记关闭，读的时候会创建临时文件，到时磁盘会崩的
        excelReader.finish();
      }
    }
    return R.ok();
  }

package com.atguigu.excel;

import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
import com.atguigu.eduservice.entity.EduTeacher;
import com.atguigu.eduservice.entity.vo.TeacherExcel;
import com.atguigu.eduservice.service.EduTeacherService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.ArrayList;
import java.util.List;

// 有个很重要的点 DemoDataListener 不能被spring管理，要每次读取excel都要new,然后里面用到spring可以构造方法传进去
public class DemoDataListener extends AnalysisEventListener {
  private static final Logger LOGGER = LoggerFactory.getLogger(DemoDataListener.class);
  //这里写持久层的类
  private EduTeacherService eduTeacherService;
  
  /**

   * 如果使用了spring,请使用这个构造方法。每次创建Listener的时候需要把spring管理的类传进来

   *

   * @param eduTeacherService

   */

  public DemoDataListener( EduTeacherService eduTeacherService) {
        //进行持久层的类
    this.eduTeacherService = eduTeacherService;

  }
  

  /**
   * 每隔5条存储数据库，实际使用中可以3000条，然后清理list ，方便内存回收
   */
  private static final int BATCH_COUNT = 5;
  List list = new ArrayList();
  /**
   * 假设这个是一个DAO，当然有业务逻辑这个也可以是一个service。当然如果不用存储这个对象没用。
   */
  //private DemoDAO demoDAO;
  public DemoDataListener() {
    // 这里是demo，所以随便new一个。实际使用如果到了spring,请使用下面的有参构造函数
    //demoDAO = new DemoDAO();
  }
  /**
   * 如果使用了spring,请使用这个构造方法。每次创建Listener的时候需要把spring管理的类传进来
   *
   * @param demoDAO
   */
  /* public DemoDataListener(DemoDAO demoDAO) {
    this.demoDAO = demoDAO;
  }*/
  /**
   * 这个每一条数据解析都会来调用
   *
   * @param data
   *      one row value. Is is same as {@link AnalysisContext#readRowHolder()}
   * @param context
   */
  @Override
  public void invoke(TeacherExcel data, AnalysisContext context) {
    LOGGER.info("解析到一条数据:{}",data.toString());
    list.add(data);
    // 达到BATCH_COUNT了，需要去存储一次数据库，防止数据几万条数据在内存，容易OOM

  }
  /**
   * 所有数据解析完成了 都会来调用
   *
   * @param context
   */
  @Override
  public void doAfterAllAnalysed(AnalysisContext context) {
    // 这里也要保存数据，确保最后遗留的数据也存储到数据库
    saveData();
    LOGGER.info("所有数据解析完成！");
  }
  /**
   * 加上存储数据库
   */
  private void saveData() {
    LOGGER.info("{}条数据，开始存储数据库！", list.size());
    //因为我excel模板的实体和插入数据库实体的类不一样，所以需要进行转化

    for (int i =0;i

@ExcelProperty(value = “讲师简介”,index = 1)
private String intro;

package com.atguigu.eduservice.config;

import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.support.ExcelTypeEnum;
import com.alibaba.excel.write.metadata.style.WriteCellStyle;
import com.alibaba.excel.write.style.HorizontalCellStyleStrategy;
import org.apache.poi.ss.usermodel.HorizontalAlignment;

import javax.servlet.http.HttpServletResponse;
import java.io.OutputStream;
import java.net.URLEncoder;
import java.util.List;

/**
 * @author linjiazeng
 * @version 1.0
 * @date 2020/12/28 22:29
 **/
public class ExcelUtil {

  /**
   * 导出
   * @param response
   * @param data
   * @param fileName
   * @param sheetName
   * @param clazz
   * @throws Exception
   */
  public static void writeExcel(HttpServletResponse response, List<&＃63; extends Object> data, String fileName, String sheetName, Class clazz) throws Exception {
    //表头样式
    WriteCellStyle headWriteCellStyle = new WriteCellStyle();
    //设置表头居中对齐
    headWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
    //内容样式
    WriteCellStyle cOntentWriteCellStyle= new WriteCellStyle();
    //设置内容靠左对齐
    contentWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.LEFT);
    HorizontalCellStyleStrategy horizOntalCellStyleStrategy= new HorizontalCellStyleStrategy(headWriteCellStyle, contentWriteCellStyle);
    EasyExcel.write(getOutputStream(fileName, response), clazz).excelType(ExcelTypeEnum.XLSX).sheet(sheetName).registerWriteHandler(horizontalCellStyleStrategy).doWrite(data);
  }
  private static OutputStream getOutputStream(String fileName, HttpServletResponse response) throws Exception {
    fileName = URLEncoder.encode(fileName, "UTF-8");
    response.setContentType("application/vnd.ms-excel");
    response.setCharacterEncoding("utf8");
    response.setHeader("Content-Disposition", "attachment;filename=" + fileName + ".xlsx");
    response.addHeader("Access-Control-Expose-Headers", "Content-disposition");

    return response.getOutputStream();
  }
}

 /*下载模板*/
  @GetMapping("/download/template")
  public void downloadTemplate(HttpServletResponse response){
    String fileName = "导入讲师模板";
    String sheetName="导入讲师模板";
    List teacherExcelList = new ArrayList<>();
    TeacherExcel teacherExcel = new TeacherExcel();
    teacherExcel.setName("ljz");
    teacherExcel.setIntro("清华毕业，高材生");
    teacherExcel.setCareer("资深讲师");
    teacherExcel.setSort(1);
    teacherExcel.setLevel(1);
    teacherExcelList.add(teacherExcel);
    try {
      //TeacherExcel.class对应你的模板类
      //teacherExcelList模板的例子
      //也可以使用这种方式导出你查询出数据excel文件
      ExcelUtil.writeExcel(response,teacherExcelList,fileName,sheetName,TeacherExcel.class);
    } catch (Exception e) {
      System.out.println(e.getCause());

    }
  }