阿里出品，Excel 操作利器：easy-excel

 

最近在做excel数据导出时，发现了一款挺好用的excel处理开源框架：easy-excel，阿里巴巴出品，github上已有10.7K Star，整个使用下来比较突出的有两点：

• 容易上手，无论是注解还是api比较好用

• 相比Apache poi，比较节约内存，避免内存溢出等问题。

下面以excel的数据导出的demo为例，谈谈该框架的应用实践

1. 使用@ExcelProperty 可以指定excel列表的标题和顺序，index用来指定写入excel标题顺序，通过该注解，实现对象与excel标题的映射。

  package com.model;

import com.alibaba.excel.annotation.ExcelProperty;
import com.alibaba.excel.metadata.BaseRowModel;

public class User extends BaseRowModel {

    /**
     * 用户id
     */
    @ExcelProperty(value = "用户id", index = 0)
    private String userId;

    /**
     * 年龄
     */
    @ExcelProperty(value = "年龄", index = 1)
    private String age;

    /**
     * 薪水
     */
    @ExcelProperty(value = "薪水", index = 2)
    private String salary;

    /**
     * 职业
     */
    @ExcelProperty(value = "职业", index = 3)
    private String profession;

    public String getUserId() {
        return userId;
    }

    public void setUserId(String userId) {
        this.userId = userId;
    }

    public String getAge() {
        return age;
    }

    public void setAge(String age) {
        this.age = age;
    }

    public String getSalary() {
        return salary;
    }

    public void setSalary(String salary) {
        this.salary = salary;
    }

    public String getProfession() {
        return profession;
    }

    public void setProfession(String profession) {
        this.profession = profession;
    }
}

1. excel下载首先要设置好HttpServletResponse参数，指定文件名时注意编码，以免出现中文乱码。

2. 服务端向客户端游览器发送文件时，如果是浏览器支持的文件类型，一般会默认使用浏览器打开，比如txt、jpg等，会直接在浏览器中显示，如果需要提示用户保存，就要利用Content-Disposition进行一下处理，关键在于一定要加上attachment

response.setHeader("Content-Disposition", "attachment;filename=" + fileName+".xlsx");

4.完整代码如下：

/**
 * Alipay.com Inc. Copyright (c) 2004-2019 All Rights Reserved.
 */
package com.controller;

import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.metadata.Sheet;
import com.alibaba.excel.support.ExcelTypeEnum;
import com.google.common.collect.Lists;
import com.model.User;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletResponse;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;

/**
 * excel下载
 */
@RestController
@RequestMapping("/user")
public class ExcelDownLoadController {

    private Logger logger = LoggerFactory.getLogger(ExcelDownLoadController.class);

    @RequestMapping(value = "/download", method = RequestMethod.GET)
    public void downLoadExcel(HttpServletResponse response) {

        try {
            this.setUpResponseAttributes(response);
            ByteArrayOutputStream stream = this.writeToExcel();
            this.writeToResponse(stream,response);
        } catch (Exception e) {
            logger.error("downLoadExcel error", e);
            throw new RuntimeException("下载excel异常");
        }
    }


    /**
     * 基于easyExcel框架，把数据写入到excel
     *
     * @return
     */
    private ByteArrayOutputStream writeToExcel() {

        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        ExcelWriter excelWriter = new ExcelWriter(byteArrayOutputStream, ExcelTypeEnum.XLSX);
        Sheet sheet = new Sheet(1, 0, User.class);
        excelWriter.write(Lists.newArrayList(buildUserData()), sheet);
        excelWriter.finish();
        return byteArrayOutputStream;
    }

    /**
     * 针对excel下载，设置相关的HttpServletResponse属性
     *
     * @param response
     */
    private void setUpResponseAttributes(HttpServletResponse response) throws UnsupportedEncodingException {

        response.setHeader("Pragma", "No-cache");
        response.setHeader("Cache-Control", "No-cache");
        response.setDateHeader("Expires", 0);
        response.setContentType("application/vnd.ms-excel");
        //解决中文乱码问题
        String fileName = new String("用户名单".getBytes("gbk"),"iso8859-1");
        // 设定输出文件头
        response.setHeader("Content-Disposition", "attachment;filename=" + fileName+".xlsx");
    }

    /**
     * 将byteStream写进response输出流中
     *
     * @param byteStream excel字节流
     * @param response   返回结果
     * @throws IOException
     */
    private void writeToResponse(ByteArrayOutputStream byteStream, HttpServletResponse response) throws IOException {

        try {
            ServletOutputStream responseStream = response.getOutputStream();
            byteStream.writeTo(responseStream);
            responseStream.flush();
        } catch (Exception e) {
            logger.error("writeToResponse error", e);
            throw e;
        } finally {
            byteStream.close();
        }
    }

    /**
     * 构建一条用户数据，用来测试
     *
     * @return
     */
    private User buildUserData() {

        User user = new User();
        user.setUserId("10241000");
        user.setAge("20");
        user.setProfession("学生");
        user.setSalary("2000");
        return user;
    }
}

5.excel下载效果

启动服务后，http://127.0.0.1:8080/user/download 下载excel，效果如下图所示

图片

github开源地址： https://github.com/alibaba/easyexcel

 

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