Hutool的使用

Hutool的Office操作

昨天听到我们头说让其他人完成一个将数据导出为excel的功能，我一开始想的是poi实现，然后问了一下发现我们公司用的是一个叫HuTool的工具类，我查看了一下官方文档，这个工具类实现的功能特别多，此次先说一下poi的操作，其他的有时间我们再聊一聊：

官方文档地址：https://www.hutool.cn/docs/#/poi/Excel生成-ExcelWriter

我做的Demo的码云地址：https://gitee.com/zym213/hutool_poi

首先引入依赖：

        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.4.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>4.1.2</version>
        </dependency>

编写测试类：

DownloadUtil:

package com.zym.testpoi.util;
import cn.hutool.core.io.IoUtil;
import cn.hutool.poi.excel.ExcelUtil;
import cn.hutool.poi.excel.ExcelWriter;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.UUID;
public class DownloadUtil {
    public static void download(List<Map<String,Object>> list,HttpServletResponse response) throws IOException {
        String path = System.getProperty("java.io.tmpdir") + UUID.randomUUID() + ".xlsx";
        File file = new File(path);//在系统的临时目录生成一个excel
        ExcelWriter writer = ExcelUtil.getWriter();
        // 一次性写出内容，使用默认样式，强制输出标题
        writer.write(list,true);
        //response为HttpServletResponse对象
        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;charset=utf-8");
        //test.xls是弹出下载对话框的文件名，不能为中文，中文请自行编码
        response.setHeader("Content-Disposition","attachment;filename=file.xlsx");
        ServletOutputStream out=response.getOutputStream();
        writer.flush(out, true);
        writer.close();
        //此处记得关闭输出Servlet流
        IoUtil.close(out);
        // 终止后删除临时文件
        file.deleteOnExit();
    }
}

User:

package com.zym.testpoi.pojo;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {
    private String username;
    private int age;
    private String hobby;
}

UserController:

package com.zym.testpoi.controller;
import com.zym.testpoi.pojo.User;
import com.zym.testpoi.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
@Controller
public class UserController {
    @Autowired
    private UserService userService;
    @GetMapping("/download")
    public void download(HttpServletResponse response) throws IOException {
        List<User> list = new ArrayList<>();
        list.add(new User("zhangsan",23,"football"));
        list.add(new User("lisi",24,"song"));
        list.add(new User("wangwu",25,"computergame"));
        userService.download(list,response);
    }
}

UserServiceImpl:

package com.zym.testpoi.service.impl;
import com.zym.testpoi.pojo.User;
import com.zym.testpoi.service.UserService;
import com.zym.testpoi.util.DownloadUtil;
import org.springframework.stereotype.Service;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
@Service
public class UserServiceImpl implements UserService {
    @Override
    public void download(List<User> list, HttpServletResponse response) throws IOException {
        List<Map<String,Object>> downloadlist = new ArrayList<>();
        for (User user : list) {
            Map<String,Object> map = new LinkedHashMap<>();
            map.put("用户名",user.getUsername());
            map.put("年龄",user.getAge());
            map.put("爱好",user.getHobby());
            downloadlist.add(map);
        }
        DownloadUtil.download(downloadlist,response);
    }
}

然后我们启动项目，调用一下download这个接口：

浏览器弹出了下载窗口，下载下来看一下是什么样子：

虽然样式丑了点，但功能实现了，接下来就是对照官方文档修改你自己想要的样式了