Springboot下载Excel的3种方式

Springboot下载Excel的3种方式

汇总一下浏览器下载和代码本地下载实现的3种方式。

（其实一般都是在代码生成excel，然后上传到oss，然后传链接给前台，但是我好像没有实现过直接点击就能在浏览器下载的功能，所以这次一起汇总一下3种实现方式。）

---

目录

• 1.EasyExcel--浏览器下载
  • 1.Maven环境
  • 2.完整代码实现
  • 3.实现效果
• 2.EasyExcel--本地下载
  • 1.完整代码实现
  • 2.实现效果
• 3.Poi--浏览器实现下载
  • 1.Maven环境
  • 2.代码实现
  • 3.实现效果
• 4.总结

1.EasyExcel--浏览器下载

1.Maven环境

​ 网络上有很多maven的easyexcel版本，还是推荐alibaba的easyexcel，操作简单，代码不冗余

        <!-- https://mvnrepository.com/artifact/com.alibaba/easyexcel -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>2.2.10</version>
        </dependency>

2.完整代码实现

• 控制层：设置response格式然后直接下载即可

package com.empirefree.springboot.controller;

import com.alibaba.excel.EasyExcel;
import com.empirefree.springboot.pojo.User;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

/**
 * @program: springboot
 * @description:
 * @author: huyuqiao
 * @create: 2021/07/04 15:01
 */

@RestController
public class UserController {

    /**
     * Author: HuYuQiao
     * Description: 浏览器下载--excel
     */
    @GetMapping("/testRespExcel")
    public void testRespExcel(HttpServletResponse response){
        response.addHeader("Content-Disposition", "attachment;filename=" + "huyuqiao.xlsx");
        response.setContentType("application/vnd.ms-excel;charset=gb2312");
        try {
//            从HttpServletResponse中获取OutputStream输出流
            ServletOutputStream outputStream = response.getOutputStream();
            /*
             * EasyExcel 有多个不同的read方法，适用于多种需求
             * 这里调用EasyExcel中通过OutputStream流方式输出Excel的write方法
             * 它会返回一个ExcelWriterBuilder类型的返回值
             * ExcelWriterBuilde中有一个doWrite方法，会输出数据到设置的Sheet中
             */
            EasyExcel.write(outputStream, User.class).sheet("测试数据").doWrite(getAllUser());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public List<User> getAllUser(){
        List<User> userList = new ArrayList<>();
        for (int i=0;i<100;i++){
            User user = User.builder().name("胡宇乔"+ i).password("huyuqiao").age(i).build();
            userList.add(user);
        }
        return userList;
    }
}

• 实体类：给User设置对应的excel属性即可,value代表excel中名字，index代表第几列

package com.empirefree.springboot.pojo;

import com.alibaba.excel.annotation.ExcelProperty;
import com.alibaba.excel.metadata.BaseRowModel;
import lombok.Builder;
import lombok.Data;

/**
 * @program: springboot
 * @description: user
 * @author: huyuqiao
 * @create: 2021/07/04 14:53
 */
@Data
@Builder
public class User  extends BaseRowModel{

    @ExcelProperty(value = "姓名",index = 0)
    private String name;

    @ExcelProperty(value = "密码",index = 1)
    private String password;

    @ExcelProperty(value = "年龄",index = 2)
    private Integer age;
}

3.实现效果

2.EasyExcel--本地下载

1.完整代码实现

​ maven和上面一样，只是文件输出流设置一下即可

package com.empirefree.springboot.controller;

import com.alibaba.excel.EasyExcel;
import com.empirefree.springboot.pojo.User;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

/**
 * @program: springboot
 * @description:
 * @author: huyuqiao
 * @create: 2021/07/04 15:01
 */

@RestController
public class UserController {
    /**
     * Author: HuYuQiao
     * Description:本地生成--excel
     */
    @GetMapping("/testLocalExcel")
    public void testLocalExcel(){
        // 文件输出位置
        OutputStream out = null;
        try {
            out = new FileOutputStream("C:\\Users\\EDY\\Desktop\\empirefree.xlsx");
            EasyExcel.write(out, User.class).sheet("测试数据").doWrite(getAllUser());
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }finally {
            try {
                // 关闭流
                out.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    }
    public List<User> getAllUser(){
        List<User> userList = new ArrayList<>();
        for (int i=0;i<100;i++){
            User user = User.builder().name("张三"+ i).password("1234").age(i).build();
            userList.add(user);
        }
        return userList;
    }
}

2.实现效果

3.Poi--浏览器实现下载

1.Maven环境

		<!-- excel导出工具 -->
		<dependency>
			<groupId>org.apache.poi</groupId>
			<artifactId>poi</artifactId>
			<version>RELEASE</version>
		</dependency>
		<dependency>
			<groupId>org.apache.poi</groupId>
			<artifactId>poi-ooxml</artifactId>
			<version>RELEASE</version>
		</dependency>

2.代码实现

• 控制层

       /**
     * Author: HuYuQiao
     * Description: excle-export
     */
    @GetMapping("/export")
    public String exportExcel(HttpServletResponse response) {
        System.out.println("成功到达到处excel....");
        String fileName = "test.xls";
        if (fileName == null || "".equals(fileName)) {
            return "文件名不能为空！";
        } else {
            if (fileName.endsWith("xls")) {
                Boolean isOk = excelService.exportExcel(response, fileName, 1, 10);
                if (isOk) {
                    return "导出成功！";
                } else {
                    return "导出失败！";
                }
            }
            return "文件格式有误！";
        }
    }

• serviceimpl层

  /**
     * Author: HuYuQiao
     * Description: excel-impl
     */
    @Override
    public Boolean exportExcel(HttpServletResponse response, String fileName, Integer pageNum, Integer pageSize) {
        log.info("导出数据开始。。。。。。");
        //查询数据并赋值给ExcelData
        List<User> userList = userMapper.find();
        System.out.println(userList.size() + "size");
        List<String[]> list = new ArrayList<String[]>();
        for (User user : userList) {
            String[] arrs = new String[4];
            arrs[0] = String.valueOf(user.getId());
            arrs[1] = user.getUsername();
            arrs[2] = user.getPassword();
            arrs[3] = String.valueOf(user.getEnable());
            list.add(arrs);
        }
        //表头赋值
        String[] head = {"序列", "用户名", "密码", "状态"};
        ExcelData data = new ExcelData();
        data.setHead(head);
        data.setData(list);
        data.setFileName(fileName);
        //实现导出
        try {
            ExcelUtil.exportExcel(response, data);
            log.info("导出数据结束。。。。。。");
            return true;
        } catch (Exception e) {
            log.info("导出数据失败。。。。。。");
            return false;
        }
    }

• 工具类

package com.example.demo.utils;

import com.example.demo.entity.ExcelData;
import com.example.demo.entity.User;
import lombok.extern.slf4j.Slf4j;
import org.apache.poi.hssf.usermodel.*;
import org.apache.poi.ss.usermodel.*;

import javax.servlet.http.HttpServletResponse;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import static org.apache.poi.ss.usermodel.CellType.*;

/**
 * Author: HuYuQiao
 * Description: excelUtil
 */
@Slf4j
public class ExcelUtil {

    /**
     * Author: HuYuQiao
     * Description: excelUtil-export
     */
    public static void exportExcel(HttpServletResponse response, ExcelData data) {
        log.info("导出解析开始，fileName:{}",data.getFileName());
        try {
            //实例化HSSFWorkbook
            HSSFWorkbook workbook = new HSSFWorkbook();
            //创建一个Excel表单，参数为sheet的名字
            HSSFSheet sheet = workbook.createSheet("sheet");
            //设置表头
            setTitle(workbook, sheet, data.getHead());
            //设置单元格并赋值
            setData(sheet, data.getData());
            //设置浏览器下载
            setBrowser(response, workbook, data.getFileName());
            log.info("导出解析成功!");
        } catch (Exception e) {
            log.info("导出解析失败!");
            e.printStackTrace();
        }
    }

    /**
     * Author: HuYuQiao
     * Description: excelUtil-settitle
     */
    private static void setTitle(HSSFWorkbook workbook, HSSFSheet sheet, String[] str) {
        try {
            HSSFRow row = sheet.createRow(0);
            //设置列宽，setColumnWidth的第二个参数要乘以256，这个参数的单位是1/256个字符宽度
            for (int i = 0; i <= str.length; i++) {
                sheet.setColumnWidth(i, 15 * 256);
            }
            //设置为居中加粗,格式化时间格式
            HSSFCellStyle style = workbook.createCellStyle();
            HSSFFont font = workbook.createFont();
            font.setBold(true);
            style.setFont(font);
            style.setDataFormat(HSSFDataFormat.getBuiltinFormat("m/d/yy h:mm"));
            //创建表头名称
            HSSFCell cell;
            for (int j = 0; j < str.length; j++) {
                cell = row.createCell(j);
                cell.setCellValue(str[j]);
                cell.setCellStyle(style);
            }
        } catch (Exception e) {
            log.info("导出时设置表头失败！");
            e.printStackTrace();
        }
    }

    /**
     * Author: HuYuQiao
     * Description: excelUtil-setData
     */
    private static void setData(HSSFSheet sheet, List<String[]> data) {
        try{
            int rowNum = 1;
            for (int i = 0; i < data.size(); i++) {
                HSSFRow row = sheet.createRow(rowNum);
                for (int j = 0; j < data.get(i).length; j++) {
                    row.createCell(j).setCellValue(data.get(i)[j]);
                }
                rowNum++;
            }
            log.info("表格赋值成功！");
        }catch (Exception e){
            log.info("表格赋值失败！");
            e.printStackTrace();
        }
    }

    /**
     * Author: HuYuQiao
     * Description: excelUtil-setBrowser
     */
    private static void setBrowser(HttpServletResponse response, HSSFWorkbook workbook, String fileName) {
        try {
            //清空response
            response.reset();
            //设置response的Header
            response.addHeader("Content-Disposition", "attachment;filename=" + fileName);
            OutputStream os = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/vnd.ms-excel;charset=gb2312");
            //将excel写入到输出流中
            workbook.write(os);
            os.flush();
            os.close();
            log.info("设置浏览器下载成功！");
        } catch (Exception e) {
            log.info("设置浏览器下载失败！");
            e.printStackTrace();
        }

    }

    /**
     * Author: HuYuQiao
     * Description: excelUtil--importExcel
     */
    public static List<Object[]> importExcel(String fileName) {
        log.info("导入解析开始，fileName:{}",fileName);
        try {
            List<Object[]> list = new ArrayList<>();
            InputStream inputStream = new FileInputStream(fileName);
            Workbook workbook = WorkbookFactory.create(inputStream);
            Sheet sheet = workbook.getSheetAt(0);
            //获取sheet的行数
            int rows = sheet.getPhysicalNumberOfRows();
            for (int i = 0; i < rows; i++) {
                //过滤表头行
                if (i == 0) {
                    continue;
                }
                //获取当前行的数据
                Row row = sheet.getRow(i);
                Object[] objects = new Object[row.getPhysicalNumberOfCells()];
                int index = 0;
                for (Cell cell : row) {
                    if (cell.getCellType().equals(NUMERIC)) {
                        objects[index] = (int) cell.getNumericCellValue();
                    }
                    if (cell.getCellType().equals(STRING)) {
                        objects[index] = cell.getStringCellValue();
                    }
                    if (cell.getCellType().equals(BOOLEAN)) {
                        objects[index] = cell.getBooleanCellValue();
                    }
                    if (cell.getCellType().equals(ERROR)) {
                        objects[index] = cell.getErrorCellValue();
                    }
                    index++;
                }
                list.add(objects);
            }
            log.info("导入文件解析成功！");
            return list;
        }catch (Exception e){
            log.info("导入文件解析失败！");
            e.printStackTrace();
        }
        return null;
    }

    //测试导入
    public static void main(String[] args) {
        try {
            String fileName = "E:/test.xlsx";
            List<Object[]> list = importExcel(fileName);
            for (int i = 0; i < list.size(); i++) {
                User user = new User();
                user.setId((Integer) list.get(i)[0]);
                user.setUsername((String) list.get(i)[1]);
                user.setPassword((String) list.get(i)[2]);
                user.setEnable((Integer) list.get(i)[3]);
                System.out.println(user.toString());
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}

3.实现效果

4.总结

总体看来：当excel需要在浏览器下载时，使用alibaba的easyexcel最快最方便，并且注意需要设置response格式