EasyExcel导入导出excel工具类

 easyexcel依赖

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>1.1.2-beat1</version>
        </dependency>

 工具类

package com.example.demo.files;


import com.alibaba.excel.EasyExcelFactory;
import com.alibaba.excel.ExcelReader;
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 com.alibaba.excel.support.ExcelTypeEnum;
import com.example.demo.timer.entity.Words;
import com.example.demo.timer.listner.ExcelListner;
import com.example.demo.timer.listner.ModelListner;
import org.apache.commons.io.FileUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.StringUtils;

import java.io.*;
import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * @describtion  easyexcel读文件生成简单的excel
 * @create-time 9:38 2019/11/25
 **/
public class ExcelUtil {
    private static Logger log = LoggerFactory.getLogger(ExcelUtil.class);
    private static Sheet initSheet;

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

    /*
     * @Description: 读excel
     * @param: [file]
     * @return: java.util.List<java.util.List<java.lang.String>>
     * @Date: 2019/12/6
     */
    public static List<List<String>> read(File file) throws FileNotFoundException {
        ExcelListner listner = new ExcelListner();
        InputStream in = new FileInputStream(file);
        ExcelTypeEnum typeEnum;
        if(file.getName().equals("xlsx")) {
            typeEnum = ExcelTypeEnum.XLSX;
        }else {
            typeEnum = ExcelTypeEnum.XLS;
        }
        ExcelReader reader = new ExcelReader(in, typeEnum,null,listner);
        reader.read();
        return listner.getData();
    }

    /*
     * @Description: 读excel
     * @param: [file]
     * @return: java.util.List<java.util.List<java.lang.String>>
     * @Date: 2019/12/6
     */
    public static List<Object> readByModel(InputStream inputStream, Class<? extends BaseRowModel> clazz,ExcelTypeEnum excelTypeEnum) {
        ModelListner listner = new ModelListner();
        ExcelReader reader = new ExcelReader(inputStream,excelTypeEnum,null,listner);
        reader.read(new Sheet(1,1,clazz));
        return listner.getDatas();
    }

    /**
     *
     * @param file 有文件时
     * @return
     * @throws FileNotFoundException
     */
    public static Object write(File file) throws FileNotFoundException {
        OutputStream out = new FileOutputStream(file);
        ExcelWriter writer = new ExcelWriter(out,ExcelTypeEnum.XLS);
        return null;
    }
    /////////////////////////////内部类实现Listener/////////////////////////////////////
    private static class ExcelListner extends AnalysisEventListener {
        private List<List<String>> data = new ArrayList<>();
        @Override
        public void invoke(Object object, AnalysisContext context) {
            List<String> list = (List<String>)object;
            data.add(list);
        }

        @Override
        public void doAfterAllAnalysed(AnalysisContext context) {

        }

        public List<List<String>> getData() {
            return data;
        }
        public void setData(List<List<String>> datas) {
            this.data = datas;
        }

    }

    private static class ModelListner extends AnalysisEventListener {
        private List<Object> datas = new ArrayList<>();
        @Override
        public void invoke(Object object, AnalysisContext context) {
            datas.add(object);
        }
        @Override
        public void doAfterAllAnalysed(AnalysisContext context) {
        }
        public List<Object> getDatas() {
            return datas;
        }
        public void setDatas(List<Object> datas) {
            this.datas = datas;
        }

    }
}