SpringBoot+EasyPoi实现excel导出功能

<!--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>

<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>

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;


public class ExcelUtils {

    
    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();
    }

    
    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);
    }


    
    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();
    }
}

package com.example.easypoiexceldemo.excel;

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

import java.util.Date;


@Data
public class ProductExcel {

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

    @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);
    }

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;


public class MapToEntity {

    
    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;
    }

    
    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;
    }
}