easyexcel读取excel与下载

  第一步导入相对应的jar
    compile 'com.alibaba:fastjson:1.2.59'
    implementation 'com.alibaba:easyexcel:1.1.2-beat1'
    implementation 'org.projectlombok:lombok:1.18.2'

  第二步建立对象

package com.example.springboot_excel.util;

import com.alibaba.excel.EasyExcelFactory;
import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
import com.alibaba.excel.metadata.BaseRowModel;
import com.alibaba.excel.metadata.Sheet;
import lombok.Data;
import lombok.Getter;
import lombok.Setter;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.CollectionUtils;
import org.springframework.util.StringUtils;

import java.io.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
* @description:
* @author: chenmingjian
* @date: 19-3-18 16:16
*/
@Slf4j
public class ExcelUtil {

    private static Sheet initSheet;

    static {
        initSheet = new Sheet(1, 0);
        initSheet.setSheetName("sheet");
        //设置自适应宽度
        initSheet.setAutoWidth(Boolean.TRUE);
    }

    /**
     * 读取少于1000行数据
     * @param filePath 文件绝对路径
     * @return
     */
    public static List<Object> readLessThan1000Row(String filePath){
        return readLessThan1000RowBySheet(filePath,null);
    }

    /**
     * 读小于1000行数据, 带样式
     * filePath 文件绝对路径
     * initSheet ：
     *      sheetNo: sheet页码，默认为1
     *      headLineMun: 从第几行开始读取数据，默认为0, 表示从第一行开始读取
     *      clazz: 返回数据List<Object> 中Object的类名
     */
    public static List<Object> readLessThan1000RowBySheet(String filePath, Sheet sheet){
        if(!StringUtils.hasText(filePath)){
            return null;
        }

        sheet = sheet != null ? sheet : initSheet;

        InputStream fileStream = null;
        try {
            fileStream = new FileInputStream(filePath);
            return EasyExcelFactory.read(fileStream, sheet);
        } catch (FileNotFoundException e) {
            log.info("找不到文件或文件路径错误, 文件：{}", filePath);
        }finally {
            try {
                if(fileStream != null){
                    fileStream.close();
                }
            } catch (IOException e) {
                log.info("excel文件读取失败, 失败原因：{}", e);
            }
        }
        return null;
    }

    /**
     * 读大于1000行数据
     * @param filePath 文件觉得路径
     * @return
     */
    public static List<Object> readMoreThan1000Row(String filePath){
        return readMoreThan1000RowBySheet(filePath,null);
    }

    /**
     * 读大于1000行数据, 带样式
     * @param filePath 文件觉得路径
     * @return
     */
    public static List<Object> readMoreThan1000RowBySheet(String filePath, Sheet sheet){
        if(!StringUtils.hasText(filePath)){
            return null;
        }

        sheet = sheet != null ? sheet : initSheet;

        InputStream fileStream = null;
        try {
            fileStream = new FileInputStream(filePath);
            ExcelListener excelListener = new ExcelListener();
            EasyExcelFactory.readBySax(fileStream, sheet, excelListener);
            return excelListener.getDatas();
        } catch (FileNotFoundException e) {
            log.error("找不到文件或文件路径错误, 文件：{}", filePath);
        }finally {
            try {
                if(fileStream != null){
                    fileStream.close();
                }
            } catch (IOException e) {
                log.error("excel文件读取失败, 失败原因：{}", e);
            }
        }
        return null;
    }

    /**
     * 生成excle
     * @param filePath  绝对路径, 如：/home/chenmingjian/Downloads/aaa.xlsx
     * @param data 数据源
     * @param head 表头
     */
    public static void writeBySimple(String filePath, List<List<Object>> data, List<String> head){
        writeSimpleBySheet(filePath,data,head,null);
    }

    /**
     * 生成excle
     * @param filePath 绝对路径, 如：/home/chenmingjian/Downloads/aaa.xlsx
     * @param data 数据源
     * @param sheet excle页面样式
     * @param head 表头
     */
    public static void writeSimpleBySheet(String filePath, List<List<Object>> data, List<String> head, Sheet sheet){
        sheet = (sheet != null) ? sheet : initSheet;

        if(head != null){
            List<List<String>> list = new ArrayList<>();
            head.forEach(h -> list.add(Collections.singletonList(h)));
            sheet.setHead(list);
        }

        OutputStream outputStream = null;
        ExcelWriter writer = null;
        try {
            outputStream = new FileOutputStream(filePath);
            writer = EasyExcelFactory.getWriter(outputStream);
            writer.write1(data,sheet);
        } catch (FileNotFoundException e) {
            log.error("找不到文件或文件路径错误, 文件：{}", filePath);
        }finally {
            try {
                if(writer != null){
                    writer.finish();
                }

                if(outputStream != null){
                    outputStream.close();
                }

            } catch (IOException e) {
                log.error("excel文件导出失败, 失败原因：{}", e);
            }
        }

    }

    /**
     * 生成excle
     * @param filePath 绝对路径, 如：/home/chenmingjian/Downloads/aaa.xlsx
     * @param data 数据源
     */
    public static void writeWithTemplate(String filePath, List<? extends BaseRowModel> data){
        writeWithTemplateAndSheet(filePath,data,null);
    }

    /**
     * 生成excle
     * @param filePath 绝对路径, 如：/home/chenmingjian/Downloads/aaa.xlsx
     * @param data 数据源
     * @param sheet excle页面样式
     */
    public static void writeWithTemplateAndSheet(String filePath, List<? extends BaseRowModel> data, Sheet sheet){
        if(CollectionUtils.isEmpty(data)){
            return;
        }

        sheet = (sheet != null) ? sheet : initSheet;
        sheet.setClazz(data.get(0).getClass());

        OutputStream outputStream = null;
        ExcelWriter writer = null;
        try {
            outputStream = new FileOutputStream(filePath);
            writer = EasyExcelFactory.getWriter(outputStream);
            writer.write(data,sheet);
        } catch (FileNotFoundException e) {
            log.error("找不到文件或文件路径错误, 文件：{}", filePath);
        }finally {
            try {
                if(writer != null){
                    writer.finish();
                }

                if(outputStream != null){
                    outputStream.close();
                }
            } catch (IOException e) {
                log.error("excel文件导出失败, 失败原因：{}", e);
            }
        }

    }

    /**
     * 生成多Sheet的excle
     * @param filePath 绝对路径, 如：/home/chenmingjian/Downloads/aaa.xlsx
     * @param multipleSheelPropetys
     */
    public static void writeWithMultipleSheel(String filePath,List<MultipleSheelPropety> multipleSheelPropetys){
        if(CollectionUtils.isEmpty(multipleSheelPropetys)){
            return;
        }

        OutputStream outputStream = null;
        ExcelWriter writer = null;
        try {
            outputStream = new FileOutputStream(filePath);
            writer = EasyExcelFactory.getWriter(outputStream);
            for (MultipleSheelPropety multipleSheelPropety : multipleSheelPropetys) {
                Sheet sheet = multipleSheelPropety.getSheet() != null ? multipleSheelPropety.getSheet() : initSheet;
                if(!CollectionUtils.isEmpty(multipleSheelPropety.getData())){
                    sheet.setClazz(multipleSheelPropety.getData().get(0).getClass());
                }
                writer.write(multipleSheelPropety.getData(), sheet);
            }

        } catch (FileNotFoundException e) {
            log.error("找不到文件或文件路径错误, 文件：{}", filePath);
        }finally {
            try {
                if(writer != null){
                    writer.finish();
                }

                if(outputStream != null){
                    outputStream.close();
                }
            } catch (IOException e) {
                log.error("excel文件导出失败, 失败原因：{}", e);
            }
        }

    }


    /*********************匿名内部类开始，可以提取出去******************************/

    @Data
    public static class MultipleSheelPropety{

        private List<? extends BaseRowModel> data;

        private Sheet sheet;
    }

    /**
     * 解析监听器，
     * 每解析一行会回调invoke()方法。
     * 整个excel解析结束会执行doAfterAllAnalysed()方法
     *
     * @author: chenmingjian
     * @date: 19-4-3 14:11
     */
    @Getter
    @Setter
    public static class ExcelListener extends AnalysisEventListener {

        private List<Object> datas = new ArrayList<>();

        /**
         * 逐行解析
         * object : 当前行的数据
         */
        @Override
        public void invoke(Object object, AnalysisContext context) {
            //当前行
            // context.getCurrentRowNum()
            if (object != null) {
                datas.add(object);
            }
        }


        /**
         * 解析完所有数据后会调用该方法
         */
        @Override
        public void doAfterAllAnalysed(AnalysisContext context) {
            //解析结束销毁不用的资源
        }

    }

    /************************匿名内部类结束，可以提取出去***************************/

}


package com.example.springboot_excel.entity;

import com.alibaba.excel.annotation.ExcelProperty;
import com.alibaba.excel.metadata.BaseRowModel;

public class User extends BaseRowModel {
    @ExcelProperty(value = "id", index = 0)
    private Integer id;

    @ExcelProperty(value = "name", index = 1)
    private String name;
    @ExcelProperty(value = "address", index = 2)
    private String address;
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

第三步方法即可
@ApiOperation(value = "读取excel----file")
    @PostMapping("/importExcel")
    public String importExcel(@RequestParam("file") MultipartFile file) throws IOException {
        InputStream inputStream = file.getInputStream();

        //实例化实现了AnalysisEventListener接口的类
        ExcelUtil.ExcelListener listener = new ExcelUtil.ExcelListener();
        //传入参数
        ExcelReader excelReader = new ExcelReader(inputStream,  null, listener);
        //读取信息
        excelReader.read(new Sheet(1, 1, User.class));
        //获取数据
        List<Object> list = listener.getDatas();

        List<User> catagoryList = new ArrayList<User>();
        User catagory = new User();

        //转换数据类型,并插入到数据库
        for (int i = 0; i < list.size(); i++) {
            catagory = (User) list.get(i);
            System.out.println(catagory.getId()+"----"+catagory.getName()+"----"+catagory.getAddress());
        }
        return "ok";
    }

下载
@GetMapping("/download")
    @ApiOperation(value = "下载excel")
    public void download(HttpServletResponse response) {
        OutputStream out = null;
        ExcelWriter writer = null;
        try {
            SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmm");
            String date = sdf.format(new Date());
            //通过查询组装数据
            List<User> userlist = new ArrayList<>();
            User user = new User();
            user.setId(1);
            user.setName("张三");
            User user1 = new User();
            user1.setId(2);
            user1.setName("李四");
            userlist.add(user);
            userlist.add(user1);
            //拼接导出的文件名
            String fileName = date + new String(("告警数据").getBytes("UTF-8"), "ISO-8859-1") + ".xlsx";
            response.addHeader("Content-Disposition", "attachment;filename=" + fileName);
            //下载到浏览器默认地址
            out = response.getOutputStream();
            writer = new ExcelWriter(out, ExcelTypeEnum.XLSX);
            Sheet sheet1 = new Sheet(1, 0, User.class);
            sheet1.setSheetName("sheet1");
            writer.write(userlist, sheet1);
            userlist.clear();
        } catch (Exception e) {
//            log.error("告警信息下载失败"+e.getMessage(),e);
        } finally {
            try {
                out.flush();
                writer.finish();
                out.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }