SpringBoot实现导出Excel表格功能

添加依赖 pom.xml

        <!-- 导出表格依赖 -->
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi</artifactId>
            <version>3.13</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>3.13</version>
        </dependency>
        <!-- mybatis-plus依赖 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.1.1</version>
        </dependency>
        <!-- 数据库连接依赖 -->
        <dependency>
            <groupId>com.sdsvs.finsvc</groupId>
            <artifactId>mysql-connector</artifactId>
            <version>1.1</version>
        </dependency>
        <!-- lombok依赖 -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

配置文件配置 application.yml

#端口号
server:
  port: 8080
##数据库的配置信息
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/user?serverTimezone=UTC&?useUnicode=true&characterEncoding=utf8 #自己的 数据库 名称
    username: root
    password: root
    driver-class-name: com.mysql.jdbc.Driver
mybatis:
  #开启驼峰命名法
  configuration:
    map-underscore-to-camel-case: true
mybatis-plus:
  # xml地址
  mapper-locations: classpath:mapper/*Mapper.xml
  # 实体扫描，多个package用逗号或者分号分隔
  type-aliases-package: com.niuben.entity   #自己的实体类地址
  configuration:
    # 这个配置会将执行的sql打印出来，在开发或测试的时候可以用
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

Excel工具类 ExcelUtils

package com.niuben.utils;

import com.niuben.model.ExcelData;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFCellStyle;
import org.apache.poi.xssf.usermodel.XSSFColor;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.apache.poi.xssf.usermodel.extensions.XSSFCellBorder.BorderSide;

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

/**
 * @author： NiuBen
 * @date： Created in 2019/12/15 19:48
 * @description：
 */
public class ExcelUtils {
    /**
     * 使用浏览器选择路径下载
     * @param response
     * @param fileName
     * @param data
     * @throws Exception
     */
    public static void exportExcel(HttpServletResponse response, String fileName, ExcelData data) throws Exception {
        // 告诉浏览器用什么软件可以打开此文件
        response.setHeader("content-Type", "application/vnd.ms-excel");
        // 下载文件的默认名称
        response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName + ".xlsx", "utf-8"));
        exportExcel(data, response.getOutputStream());
    }


    private static int exportExcel(ExcelData data, OutputStream out) throws Exception {
        XSSFWorkbook wb = new XSSFWorkbook();
        int rowIndex = 0;
        try {
            String sheetName = data.getName();
            if (null == sheetName) {
                sheetName = "Sheet1";
            }
            XSSFSheet sheet = wb.createSheet(sheetName);
            rowIndex = writeExcel(wb, sheet, data);
            wb.write(out);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            //此处需要关闭 wb 变量
            out.close();
        }
        return rowIndex;
    }


    /**
     * 表显示字段
     * @param wb
     * @param sheet
     * @param data
     * @return
     */
    private static int writeExcel(XSSFWorkbook wb, Sheet sheet, ExcelData data) {
        int rowIndex = 0;
        rowIndex = writeTitlesToExcel(wb, sheet, data.getTitles());
        rowIndex = writeRowsToExcel(wb, sheet, data.getRows(), rowIndex);
        autoSizeColumns(sheet, data.getTitles().size() + 1);
        return rowIndex;
    }
    /**
     * 设置表头
     *
     * @param wb
     * @param sheet
     * @param titles
     * @return
     */
    private static int writeTitlesToExcel(XSSFWorkbook wb, Sheet sheet, List<String> titles) {
        int rowIndex = 0;
        int colIndex = 0;
        Font titleFont = wb.createFont();
        //设置字体
        titleFont.setFontName("simsun");
        //设置粗体
        titleFont.setBoldweight(Short.MAX_VALUE);
        //设置字号
        titleFont.setFontHeightInPoints((short) 14);
        //设置颜色
        titleFont.setColor(IndexedColors.BLACK.index);
        XSSFCellStyle titleStyle = wb.createCellStyle();
        //水平居中
        titleStyle.setAlignment(XSSFCellStyle.ALIGN_CENTER);
        //垂直居中
        titleStyle.setVerticalAlignment(XSSFCellStyle.VERTICAL_CENTER);
        //设置图案颜色
        titleStyle.setFillForegroundColor(new XSSFColor(new Color(182, 184, 192)));
        //设置图案样式
        titleStyle.setFillPattern(XSSFCellStyle.SOLID_FOREGROUND);
        titleStyle.setFont(titleFont);
        setBorder(titleStyle, BorderStyle.THIN, new XSSFColor(new Color(0, 0, 0)));
        Row titleRow = sheet.createRow(rowIndex);
        titleRow.setHeightInPoints(25);
        colIndex = 0;
        for (String field : titles) {
            Cell cell = titleRow.createCell(colIndex);
            cell.setCellValue(field);
            cell.setCellStyle(titleStyle);
            colIndex++;
        }
        rowIndex++;
        return rowIndex;
    }

    /**
     * 设置内容
     *
     * @param wb
     * @param sheet
     * @param rows
     * @param rowIndex
     * @return
     */
    private static int writeRowsToExcel(XSSFWorkbook wb, Sheet sheet, List<List<Object>> rows, int rowIndex) {
        int colIndex;
        Font dataFont = wb.createFont();
        dataFont.setFontName("simsun");
        dataFont.setFontHeightInPoints((short) 14);
        dataFont.setColor(IndexedColors.BLACK.index);

        XSSFCellStyle dataStyle = wb.createCellStyle();
        dataStyle.setAlignment(XSSFCellStyle.ALIGN_CENTER);
        dataStyle.setVerticalAlignment(XSSFCellStyle.VERTICAL_CENTER);
        dataStyle.setFont(dataFont);
        setBorder(dataStyle, BorderStyle.THIN, new XSSFColor(new Color(0, 0, 0)));
        for (List<Object> rowData : rows) {
            Row dataRow = sheet.createRow(rowIndex);
            dataRow.setHeightInPoints(25);
            colIndex = 0;
            for (Object cellData : rowData) {
                Cell cell = dataRow.createCell(colIndex);
                if (cellData != null) {
                    cell.setCellValue(cellData.toString());
                } else {
                    cell.setCellValue("");
                }
                cell.setCellStyle(dataStyle);
                colIndex++;
            }
            rowIndex++;
        }
        return rowIndex;
    }

    /**
     * 自动调整列宽
     *
     * @param sheet
     * @param columnNumber
     */
    private static void autoSizeColumns(Sheet sheet, int columnNumber) {
        for (int i = 0; i < columnNumber; i++) {
            int orgWidth = sheet.getColumnWidth(i);
            sheet.autoSizeColumn(i, true);
            int newWidth = (int) (sheet.getColumnWidth(i) + 100);
            if (newWidth > orgWidth) {
                sheet.setColumnWidth(i, newWidth);
            } else {
                sheet.setColumnWidth(i, orgWidth);
            }
        }
    }

    /**
     * 设置边框
     *
     * @param style
     * @param border
     * @param color
     */
    private static void setBorder(XSSFCellStyle style, BorderStyle border, XSSFColor color) {
        style.setBorderTop(border);
        style.setBorderLeft(border);
        style.setBorderRight(border);
        style.setBorderBottom(border);
        style.setBorderColor(BorderSide.TOP, color);
        style.setBorderColor(BorderSide.LEFT, color);
        style.setBorderColor(BorderSide.RIGHT, color);
        style.setBorderColor(BorderSide.BOTTOM, color);
    }
}

创建实体类 UserInfo

package com.niuben.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;
import lombok.EqualsAndHashCode;
import lombok.experimental.Accessors;

/**
 * @author： NiuBen
 * @date： Created in 2019/12/15 19:59
 * @description：
 */
@Data
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
@TableName(value = "userInfo")
public class UserInfo {
    @TableId(value = "ID", type = IdType.AUTO)
    private Integer id;
    @TableField("userName")
    private String userName;
    @TableField("password")
    private String password;
}

创建mapper层 UserInfoMapper

package com.niuben.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.niuben.entity.UserInfo;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface UserInfoMapper extends BaseMapper<UserInfo> {
}

在rescurces下创建 mapper/UserInfoMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.niuben.mapper.UserInfo">

</mapper>

创建service层 UserInfoService

package com.niuben.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.niuben.entity.UserInfo;

public interface UserInfoService extends IService<UserInfo> {
}

创建Impl层 UserInfoServiceImpl

package com.niuben.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.niuben.entity.UserInfo;
import com.niuben.mapper.UserInfoMapper;
import com.niuben.service.UserInfoService;
import org.springframework.stereotype.Service;

/**
 * @author： NiuBen
 * @date： Created in 2019/12/15 20:05
 * @description：
 */
@Service
public class UserInfoServiceImpl extends ServiceImpl<UserInfoMapper,UserInfo> implements UserInfoService {

}

创建表格model封装表格数据 ExcelData

package com.niuben.model;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;
import java.util.List;

/**
 * @author： NiuBen
 * @date： Created in 2019/12/15 19:47
 * @description：
 */
@Data
@AllArgsConstructor
@NoArgsConstructor
public class ExcelData implements Serializable {
    private static final long serialVersionUID = 6133772627258154184L;
    /**
     * 表头
     */
    private List<String> titles;

    /**
     * 数据
     */
    private List<List<Object>> rows;

    /**
     * 页签名称
     */
    private String name;
}

创建controller层 ExcelController

package com.niuben.controller;

import com.niuben.entity.UserInfo;
import com.niuben.model.ExcelData;
import com.niuben.service.impl.UserInfoServiceImpl;
import com.niuben.utils.ExcelUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletResponse;
import java.util.ArrayList;
import java.util.List;

/**
 * @author： NiuBen
 * @date： Created in 2019/12/15 19:51
 * @description：
 */
@Controller
@RequestMapping("/excel")
public class ExcelController {

    @Autowired
    UserInfoServiceImpl userInfoService;

    @RequestMapping("/exportExcel")
    public void test2(HttpServletResponse response){
        List<UserInfo> list = userInfoService.list();
        ExcelData data = new ExcelData();
        // 设置sheet页名
        data.setName("hello");
        List<String> titles = new ArrayList();
        titles.add("ID");
        titles.add("用户名");
        titles.add("密码");
        data.setTitles(titles);

        List<List<Object>> rows = new ArrayList();
        for(int i = 0, length = list.size();i<length;i++){
            UserInfo userInfo = list.get(i);
            List<Object> row = new ArrayList();
            row.add(userInfo.getId());
            row.add(userInfo.getUserName());
            row.add(userInfo.getPassword());
            rows.add(row);
        }
        data.setRows(rows);
        try{
            ExcelUtils.exportExcel(response,"表格名称",data);
        }catch (Exception e){
            e.printStackTrace();
        }
    }
}