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SpringBoot实现excel导出

12程序猿 人气:0

在实际项目开发中,对于Excel的导入导出还是很常见的需求,比如说将数据根据模板批量导入到数据库中,以及将数据库中的数据批量导出陈Excel的形式

现有需求: 根据检索条件查询列表并将结果导出到excel

Easypoi文档:https://easypoi.mydoc.io/#text_186900

EasyPoi的主要特点

1.设计精巧,使用简单
2.接口丰富,扩展简单
3.默认值多,write less do more
4.spring mvc支持,web导出可以简单明了

实现过程

1.创建一个Spring Boot项目

快速生成链接:start.spring.io

在这里插入图片描述

2.引入EasyPoi的pom依赖

<!--EasyPoi导入导出-->
<dependency>
   <groupId>cn.afterturn</groupId>
   <artifactId>easypoi-base</artifactId>
   <version>4.3.0</version>
</dependency>
<dependency>
   <groupId>cn.afterturn</groupId>
   <artifactId>easypoi-web</artifactId>
   <version>4.3.0</version>
</dependency>
<dependency>
   <groupId>cn.afterturn</groupId>
   <artifactId>easypoi-annotation</artifactId>
   <version>4.3.0</version>
</dependency>

sax 导入使用xercesImpl这个包(这个包可能造成奇怪的问题哈),word导出使用poi-scratchpad,都作为可选包了

pom.xml中的所有依赖:

<dependencies>
     <!-- 导入web支持:SpringMVC开发支持,Servlet相关的程序 -->
     <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-web</artifactId>
     </dependency>

     <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-devtools</artifactId>
         <scope>runtime</scope>
         <optional>true</optional>
     </dependency>
     <dependency>
         <groupId>org.projectlombok</groupId>
         <artifactId>lombok</artifactId>
         <optional>true</optional>
     </dependency>
     <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-test</artifactId>
         <scope>test</scope>
     </dependency>
     <!-- mybatis相关的依赖 -->
     <!--mybatis-plus自动的维护了mybatis以及mybatis-spring的依赖,
     在springboot中这三者不能同时的出现,避免版本的冲突,表示:跳进过这个坑-->
     <!--mybatis-plus-->
     <dependency>
         <groupId>com.baomidou</groupId>
         <artifactId>mybatis-plus-boot-starter</artifactId>
         <version>3.4.3</version>
     </dependency>
     <!--mysql驱动-->
     <dependency>
         <groupId>mysql</groupId>
         <artifactId>mysql-connector-java</artifactId>
         <scope>runtime</scope>
     </dependency>
     <!-- alibaba的druid数据库连接池 -->
     <dependency>
         <groupId>com.alibaba</groupId>
         <artifactId>druid</artifactId>
         <version>1.1.20</version>
     </dependency>
     <!-- alibaba的druid数据库连接池 -->
     <dependency>
         <groupId>com.alibaba</groupId>
         <artifactId>druid-spring-boot-starter</artifactId>
         <version>1.1.20</version>
     </dependency>
     <!--swagger2依赖-->
     <dependency>
         <groupId>io.springfox</groupId>
         <artifactId>springfox-swagger2</artifactId>
         <version>2.9.2</version>
         <!--排除自身的依赖1.5.20版本-->
         <exclusions>
             <exclusion>
                 <groupId>io.swagger</groupId>
                 <artifactId>swagger-models</artifactId>
             </exclusion>
         </exclusions>
     </dependency>
     <dependency>
         <groupId>io.springfox</groupId>
         <artifactId>springfox-swagger-ui</artifactId>
         <version>2.9.2</version>
     </dependency>
     <!--此版本解决 example="" 造成的 空字符串""无法转成Number 问题-->
     <dependency>
         <groupId>io.swagger</groupId>
         <artifactId>swagger-models</artifactId>
         <version>1.5.21</version>
     </dependency>
     <!--EasyPoi导入导出-->
     <dependency>
         <groupId>cn.afterturn</groupId>
         <artifactId>easypoi-base</artifactId>
         <version>4.3.0</version>
     </dependency>
     <dependency>
         <groupId>cn.afterturn</groupId>
         <artifactId>easypoi-web</artifactId>
         <version>4.3.0</version>
     </dependency>
     <dependency>
         <groupId>cn.afterturn</groupId>
         <artifactId>easypoi-annotation</artifactId>
         <version>4.3.0</version>
     </dependency>

     <!--fastjson-->
     <dependency>
         <groupId>com.alibaba</groupId>
         <artifactId>fastjson</artifactId>
         <version>1.2.71</version>
     </dependency>
 </dependencies>

3.编写excel工具类

package com.example.easypoiexceldemo.utils;

import cn.afterturn.easypoi.excel.ExcelExportUtil;
import cn.afterturn.easypoi.excel.entity.ExportParams;
import cn.afterturn.easypoi.excel.entity.enmus.ExcelType;
import org.apache.commons.lang3.StringUtils;
import org.apache.poi.ss.usermodel.Workbook;
import org.springframework.beans.BeanUtils;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.net.URLEncoder;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.List;

/**
 * excel工具类
 * @author qzz
 */
public class ExcelUtils {

    /**
     * Excel导出
     *
     * @param response      response
     * @param fileName      文件名
     * @param list          数据List
     * @param pojoClass     对象Class
     */
    public static void exportExcel(HttpServletResponse response, String fileName, Collection<?> list, Class<?> pojoClass) throws IOException {
        if (StringUtils.isBlank(fileName)) {
            //当前日期
            SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
            fileName = df.format(new Date());
        }
        Workbook workbook = ExcelExportUtil.exportExcel(new ExportParams(fileName, fileName, ExcelType.HSSF), pojoClass, list);
        response.setCharacterEncoding("UTF-8");
        response.setHeader("content-Type", "application/vnd.ms-excel");
        response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8") + ".xls");
        ServletOutputStream out = response.getOutputStream();
        workbook.write(out);
        out.flush();
    }

    /**
     * Excel导出,先sourceList转换成List<targetClass>,再导出
     *
     * @param response      response
     * @param fileName      文件名
     * @param sourceList    原数据List
     * @param targetClass   目标对象Class
     */
    public static void exportExcelToTarget(HttpServletResponse response, String fileName, Collection<?> sourceList, Class<?> targetClass) throws Exception {
        List targetList = new ArrayList<>(sourceList.size());
        for (Object source : sourceList) {
            Object target = targetClass.newInstance();
            BeanUtils.copyProperties(source, target);
            targetList.add(target);
        }
        exportExcel(response, fileName, targetList, targetClass);
    }


    /**
     * Excel导出----设置title---sheetName---要求Collection<?> list是Class<?> pojoClass类型的
     *
     * @param response      response
     * @param fileName      文件名
     * @param list          数据List
     * @param pojoClass     对象Class
     */
    public static void exportExcel(HttpServletResponse response, String title, String sheetName, String fileName, Collection<?> list, Class<?> pojoClass) throws IOException {
        if (StringUtils.isBlank(fileName)) {
            //当前日期
            SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
            fileName = df.format(new Date());
        }
        Workbook workbook = ExcelExportUtil.exportExcel(new ExportParams(title, sheetName, ExcelType.HSSF), pojoClass, list);
        response.setCharacterEncoding("UTF-8");
        response.setHeader("content-Type", "application/vnd.ms-excel");
        response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8") + ".xls");
        ServletOutputStream out = response.getOutputStream();
        workbook.write(out);
        out.flush();
    }
}

4.在实体类上加注解@Excel

我这边使用了lombok。getter setter和构造方法通过注解 @Data @AllArgsConstructor进行添加,不使用lombok也可手动添加。

要导出的数据可在实体类对应属性上方加**@Excel()注解**。可定义导出列的名称、宽度,以及性别可区分化(一般数据库中存储的性别为1和2),日期格式化等等。

package com.example.easypoiexceldemo.excel;

import cn.afterturn.easypoi.excel.annotation.Excel;
import lombok.Data;

import java.util.Date;

/**
 * 商品
 * @author qzz
 */
@Data
public class ProductExcel {

    /**
     * 商品id
     */
    @Excel(name = "商品id")
    private Integer product_id;
    /**
     * 商品标题
     */
    @Excel(name="商品标题")
    private String title;
    /**
     * 商品副标题
     */
    @Excel(name="商品副标题")
    private String sub_title;
    /**
     * 商品售价
     */
    @Excel(name="商品售价")
    private Double sale_price;
    /**
     * 创建者
     */
    @Excel(name="创建者")
    private Integer create_by;
    /**
     * 创建时间
     */
    @Excel(name="创建时间", format = "yyyy-MM-dd")
    private Date create_time;
    /**
     * 修改时间
     */
    @Excel(name="修改时间", format = "yyyy-MM-dd")
    private Date update_time;
    /**
     * 修改者id
     */
    @Excel(name="修改者id")
    private Integer update_by;
}

@Excel 作用到filed上面,是对Excel一列的一个描述

@Excel 的属性介绍:

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在这里插入图片描述

5.Controller

/**
     * excel导出
     * @param response
     */
    @GetMapping("/excel")
    @ApiOperation("根据检索条件查询列表,导出excel")
    public void export( HttpServletResponse response) throws IOException {
        //根据条件检索列表
        QueryWrapper<Product> queryWrapper = new QueryWrapper();
        //根据条件检索商品列表
        List<Map<String, Object>> list = productService.selectList(queryWrapper);
        //将List<Map<String, Object>>结果集转换成List<ProductExcel>
        List<ProductExcel> productList = MapToEntity.setList(list,ProductExcel.class);
        //导出excel
        ExcelUtils.exportExcel(response,null,productList, ProductExcel.class);
    }

setList方法为工具类,用于将List<Map<String, Object>>结果集转换成List

MapToEntity工具类:

package com.example.easypoiexceldemo.utils;

import org.apache.commons.lang3.StringUtils;

import java.lang.reflect.Field;
import java.math.BigDecimal;
import java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Map;

/**
 * List<Map<String,Object>>到List<T>数据转换
 * @author qzz
 */
public class MapToEntity {

    /**
     * List<Map<String, Object>> 到 List<T> 数据转换
     */
    public static <T> List<T> setList(final List<Map<String, Object>> srcList, Class<T> clazz) {
        List<T> list = new ArrayList<>();
        for (int i=0;i<srcList.size();i++){
            try {
                T t = clazz.newInstance();
                Field[] fields = t.getClass().getDeclaredFields();
                for (Field field : fields) {
                    if (!"serialVersionUID".equals(field.getName())) {
                        //设置对象的访问权限,保证对private的属性的访问
                        field.setAccessible(true);
                        //读取配置转换字段名,并从map中取出数据
                        Object v = srcList.get(i).get(field.getName());
                        field.set(t, convert(v, field.getType()));
                    }
                }
                list.add(t);
            } catch (Exception ex) {
                ex.toString();
            }

        };
        return list;
    }

    /**
     * 字段类型转换
     */
    private static <T> T convert(Object obj, Class<T> type) throws ParseException {
        if (obj != null && StringUtils.isNotBlank(obj.toString())) {
            if (type.equals(String.class)) {
                return (T) obj.toString();
            } else if (type.equals(BigDecimal.class)) {
                return (T) new BigDecimal(obj.toString());
            }else if(type.equals(Double.class)){
                return (T) Double.valueOf(obj.toString());
            }else if(type.equals(Integer.class)){
                return (T) Integer.valueOf(obj.toString());
            }else if(type.equals(Date.class)){
                if(obj!=null){
                    String timeStr = String.valueOf(obj);
                    String s[] = timeStr.split("T");
                    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                    return (T) sdf.parse(s[0]+" "+s[1]);
                }else{
                    return null;
                }
            }
            else{
                //其他类型转换
                return (T) obj.toString();
            }

        }
        return null;
    }
}

6.启动项目,进行测试

项目启动成功后,在浏览器中输入 http://localhost:8083/product/excel,进行访问:

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打开导出的excel文档:

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