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。）

---

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