easyexcel 读取大excel 十万级 java

转发请注明：https://blog.csdn.net/somdip/article/details/85243005

		com.alibaba
		easyexcel
		1.0.4

package com.navitek.crawer.excelTest;

import com.alibaba.excel.ExcelReader;
import com.alibaba.excel.ExcelWriter;
import com.alibaba.excel.metadata.Sheet;
import com.alibaba.excel.read.context.AnalysisContext;
import com.alibaba.excel.read.event.AnalysisEventListener;
import com.alibaba.excel.support.ExcelTypeEnum;
import org.springframework.util.StringUtils;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * @author somdip
 * @since 1.0 2018-09-28
 */
public class EasyExcelTest {

    public static void main(String[] args) {

        long act = System.currentTimeMillis();
        String filepath ="E:\\all_cach\\31.xlsx";


        List sheetContent = read(filepath);
        //write();

        System.out.println("一共"+sheetContent.size()+"有效数据");
        long end = System.currentTimeMillis();
        System.out.println("耗时间=======:"+(end-act)+"毫秒");
        
        System.out.println(listUser.size());


    }

    private static  List read(String filepath) {
        List sheetContent = new ArrayList<>();

        //String filepath ="E:\\all_cach\\1.xlsx";
        try (InputStream inputStream = new FileInputStream(filepath)) {
            ExcelReader excelReader = new ExcelReader(inputStream, ExcelTypeEnum.XLSX, null,
                    new AnalysisEventListener>() {

                @Override
                public void invoke(List object, AnalysisContext context) {
                    /**
                     * 自行添加syl 》》》
                     */
                    StringBuffer stringBuffer = new StringBuffer();
                    if(object != null && !StringUtils.isEmpty(object.get(0))){
                        for(String s: object){
                            if(null!=s){
                                stringBuffer.append(s+"=");
                            }
                        }
                        System.out.println("行=="+context.getCurrentRowNum()+":  "+stringBuffer.toString());

                        sheetContent.add(stringBuffer.toString());
                        /**
                         *  《《《自行添加结束
                         */
                        System.out.println("当前sheet:" + context.getCurrentSheet().getSheetNo() + ",当前行:" +
                                context.getCurrentRowNum());
                    }

                }

                @Override
                public void doAfterAllAnalysed(AnalysisContext context) {

                }
            });
            excelReader.read();
        } catch (Exception e) {
            e.printStackTrace();
        }
    return sheetContent;

    }


}

亲测十万行16列左右大约耗费三秒左右，3列耗费1秒左右。

解决OOM（内存溢出）。

bug :对单元格中的“<”  ，“ >”敏感，有的话 数据发生错乱，目前无解，只能把列删去或者避免。

参考原文地址：https://blog.csdn.net/wang704987562/article/details/82887611

推荐HSSFWorkbook方式  https://blog.csdn.net/somdip/article/details/89814268