使用alibaba的easyExcel自定义工具类进行导入导出操作

平常工作经常遇到excel导入导出，easyExcel也是基于poi开发的，但是相对来说内存占用比较小，功能也更丰富，根据本人日常工作需要，抽取了excel导入导出的工具类，若有不足，请指出一起成长~

POM依赖

        <dependency>
            <groupId>com.alibabagroupId>
            <artifactId>easyexcelartifactId>
            <version>2.1.7version>
        dependency>

modo

package cn.itcast.boot.entity;

import com.alibaba.excel.annotation.ExcelIgnore;
import com.alibaba.excel.annotation.ExcelProperty;
import com.alibaba.excel.annotation.format.DateTimeFormat;
import com.alibaba.excel.annotation.write.style.ColumnWidth;
import com.alibaba.excel.annotation.write.style.HeadRowHeight;
import com.fasterxml.jackson.annotation.JsonFormat;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.math.BigDecimal;
import java.util.Date;

@Data
@AllArgsConstructor
@NoArgsConstructor
@ColumnWidth(40)
@HeadRowHeight(25)
public class Student {
    /**
     * 年龄
     */
    @ColumnWidth(20)
    @ExcelProperty("年龄")
    private int age;
    /**
     * 名字
     */
    @ExcelProperty("名字")
    private String name;
    /**
     * 年级
     */
    @ExcelIgnore
    private String classes;
    /**
     * 分数
     */
    @ExcelProperty("分数")
    private BigDecimal score;
    /**
     * 维护日期
     */
    //此注解作用：将数据库查询的日期，以指定格式转换为字符串格式传给前端 Date->json
    @JsonFormat(pattern = "yyyy-MM-dd",timezone = "GMT+8")
    //Excel导出时，日期字段按照指定字段导出
    @DateTimeFormat("yyyy-MM-dd")
    //controller层接收参数将字符串转为日期 json->Date
    @org.springframework.format.annotation.DateTimeFormat(pattern = "yyyy-MM-dd")
    private Date mntDte;
}

工具类

package cn.itcast.boot.ExcelUtil;

import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
import com.alibaba.excel.support.ExcelTypeEnum;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.MediaType;

import javax.servlet.http.HttpServletResponse;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.util.*;
import java.util.function.Consumer;
import static com.alibaba.excel.EasyExcelFactory.write;
public class EasyExcelUtils {
    private static final Logger LOGGER = LoggerFactory.getLogger(EasyExcelUtils.class);

    public static <T> AnalysisEventListener<T> getListener(Consumer<List<T>> consumer,int threshold){
        return new AnalysisEventListener<T>() {
            /**
             * 存储数据集合
             */
            private List<T> list = new LinkedList<T>();
            /**
             * 这个每一条数据解析都会调用一次
             * @param t
             * @param analysisContext
             */
            @Override
            public void invoke(T t, AnalysisContext analysisContext) {
                list.add(t);
                if (list.size() == threshold){
                    consumer.accept(list);
                    list.clear();
                }

            }

            /**
             * 所有数据解析完成 自动调用此方法
             * @param analysisContext
             */
            @Override
            public void doAfterAllAnalysed(AnalysisContext analysisContext) {
                if (list.size()>0){
                    consumer.accept(list);
                }
            }
        };
    }

    /**
     * 根据指定字段导出数据
     * @param response
     * @param colums
     * @param dataList
     * @param aClass
     */
    public static void exportExcel(HttpServletResponse response,String[] colums, List<?> dataList,Class<?> aClass){
        try {
            //添加要导出的字段
            Set<String> includeList = new HashSet<>();
            Collections.addAll(includeList,colums);
            //设置返回类型及编码类型
            response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);
            response.setCharacterEncoding("UTF-8");
            //写出
            write(new BufferedOutputStream(response.getOutputStream()),aClass)
                    .autoCloseStream(true)
                    .excelType(ExcelTypeEnum.XLSX)
                    .includeColumnFiledNames(includeList)
                    .sheet().doWrite(dataList);
        }catch (IOException e){
            LOGGER.error(e.getMessage());
        }
    }

    /**
     * 不指定导出字段
     * 不需要导出的字段需要使用注解标记@ExcelIgnore
     * 按照实体类中注解标记顺序导出
     *
     * @param response
     * @param dataList
     * @param aClass
     */
    public static void exportExcel(HttpServletResponse response,List<?> dataList,Class<?> aClass){
        try {
            //设置返回类型及编码类型
            response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);
            response.setCharacterEncoding("UTF-8");
            //写出
            write(new BufferedOutputStream(response.getOutputStream()),aClass)
                    .autoCloseStream(true)
                    .excelType(ExcelTypeEnum.XLSX)
                    .sheet().doWrite(dataList);
        }catch (IOException e){
            LOGGER.error(e.getMessage());
        }
    }
}

导入Controller层

 /**
     * 注： 逻辑代码尽量不要写在controller层，此处仅为方便演示
     *
     * easyExcel自定义工具类excel批量导入
     * @param file
     */
    @PostMapping("/excelAppend")
    public void excelAppend(@RequestParam MultipartFile file) throws IOException {
        AnalysisEventListener<Object> listener =
                EasyExcelUtils.getListener(list -> excelBatchAppendService.excelAppend(list), 10000);
        EasyExcelFactory.read(new BufferedInputStream(file.getInputStream()), Student.class,listener);
    }

service层

    /**
     * excel批量导入
     * @param list
     */
    @Override
    public void excelAppend(List<Object> list) {
        //TODO 处理excel中数据 list
    }

导出

    @PostMapping("/batchExport")
    public void batchExport(HttpServletResponse response){
        List<Student> dateList = getDateList();
        EasyExcelUtils.exportExcel(response,dateList,Student.class);
    }


    public List<Student> getDateList(){
        List<Student> students = new ArrayList<>();
        Collections.addAll(students,
                new Student(10,"小红","三年二班",new BigDecimal(100),new Date()),
                new Student(12,"小蓝","三年二班",new BigDecimal(80.50),new Date()),
                new Student(11,"小绿","三年二班",new BigDecimal(22.30),new Date()),
                new Student(11,"小紫","三年二班",new BigDecimal(65.66),new Date())
        );
        return students;
    }