网站推广优化建设,优就业seo,网站开发 兼容模式,广州哪个区封了前言 在遇到大数据量excel#xff0c;50MB大小或数百万级别的数据读取时#xff0c;使用常用的POI容易导致读取时内存溢出或者cpu飙升。 本文讨论的是针对xlsx格式的excel文件上传#xff0c;采用com.monitorjbl.xlsx.StreamingReader 。 什么是StreamReader? StreamReader…前言 在遇到大数据量excel50MB大小或数百万级别的数据读取时使用常用的POI容易导致读取时内存溢出或者cpu飙升。 本文讨论的是针对xlsx格式的excel文件上传采用com.monitorjbl.xlsx.StreamingReader 。 什么是StreamReader? StreamReader 是 java.io 包中的一个类用于读取字符流的高级类。它继承自 Reader 类可以以字符为单位读取文件中的数据。StreamReader的主要功能 以字符为单位读取文件中的数据提供了多种读取方法如read()、readLine()等可以指定字符编码以适应不同类型的文件 StreamReader的优势 简化了文件读取的过程提供了高层次的读取方法可以处理不同类型的文件如文本文件、CSV文件等可以读取大型文件节省内存空间 注StreamReader只能用遍历形式读取数据 Sheet sheet wk.getSheetAt(0);//遍历所有的行for (Row row : sheet) {System.out.println(开始遍历第 row.getRowNum() 行数据);//遍历所有的列for (Cell cell : row) {System.out.print(cell.getStringCellValue() );}System.out.println( );} 案例步骤
1、导入文件前端接口 Controller.java /*** 导入文件前端接口*/PostMapping(/importData)ResponseBodypublic AjaxResult importData(MultipartFile file, boolean updateSupport) throws Exception {// 开始时间Long begin new Date().getTime();// excel转换为List集合约30s~40sListTpInstallationMaintenanceLabelDetailed tpInstallationMaintenanceLabelDetailedList largeFilesUtils.importExcelLargeFile(file, updateSupport);// 结束时间Long end new Date().getTime();// 数据导入约30sString message importInstallationMaintenanceLabelDetailed(tpInstallationMaintenanceLabelDetailedList, updateSupport);// 总用时(约60s~70s)message message br/数据转换花费时间 : (end - begin) / 1000 s ;// 返回return AjaxResult.success(message);}
2、Excel数据转为List largeFilesUtils.java import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;import com.monitorjbl.xlsx.StreamingReader;
import com.ruoyi.huawei.domain.TpInstallationMaintenanceLabelDetailed;/*** 大文件Excel导入* * author y* date 2024-03-29*/
Service
public class LargeFilesUtils {/*** 大文件Excel导入* * param* return 工具*/public ListTpInstallationMaintenanceLabelDetailed importExcelLargeFile(MultipartFile file,boolean updateSupport) {ListTpInstallationMaintenanceLabelDetailed tpInstallationMaintenanceLabelDetailedList new ArrayListTpInstallationMaintenanceLabelDetailed();try {// 大文件测试开始InputStream inputStream file.getInputStream();// com.monitorjbl.xlsx.StreamingReader Workbook workbook StreamingReader.builder().rowCacheSize(1000) // 缓存到内存中的行数(默认是10).bufferSize(10240) // 读取资源时缓存到内存的字节大小(默认是1024).open(inputStream);// 获取第一个ShhetSheet sheet workbook.getSheetAt(0);//boolean fastRowBoolean true;// monitorjbl只能支持遍历不能通过指定下标获取for (Row row : sheet) {// 判断是否首行if(fastRowBoolean) {// 设置为非首行fastRowBoolean false;// continue 语句用于跳过当前循环中剩余的代码并开始下一次迭代。continue;}// 创建实体TpInstallationMaintenanceLabelDetailed rowData new TpInstallationMaintenanceLabelDetailed();// 列下标初始化int n 0;// 遍历列for (Cell cell : row) {//switch (n) {// 第一列case 0:rowData.setPppoeAccount(cell.getStringCellValue());break;// 第二列case 1:rowData.setInstallationMaintenanceName(cell.getStringCellValue());break;case 2:rowData.setCounty(cell.getStringCellValue());break;case 3:rowData.setPoorQualityUser(cell.getStringCellValue());break;case 4:rowData.setOldLightCat(cell.getStringCellValue());break;case 5:rowData.setSetTopBoxWirelessConnection(cell.getStringCellValue());break;case 6:rowData.setPleaseUseXgponOnu(cell.getStringCellValue());break;case 7:rowData.setHighTemperatureLightCat(cell.getStringCellValue());break;case 8:rowData.setAnOldSetTopBox(cell.getStringCellValue());break;case 9:rowData.setTwoOldSetTopBoxes(cell.getStringCellValue());break;case 10:rowData.setThreeOldSetTopBoxes(cell.getStringCellValue());break;case 11:rowData.setAnPoorQualityRouter(cell.getStringCellValue());break;case 12:rowData.setTwoPoorQualityRouters(cell.getStringCellValue());break;case 13:rowData.setThreePoorQualityRouters(cell.getStringCellValue());break;case 14:rowData.setThreeOrMoreLowQualityRouters(cell.getStringCellValue());break;case 15:rowData.setThreeOrMoreOldSetTopBoxes(cell.getStringCellValue());break;case 16:rowData.setSeverelyPoorQualityUsersAndOldOpticalCats(cell.getStringCellValue());break;// 处理其他属性default:break;}// 列下标1n n1;}tpInstallationMaintenanceLabelDetailedList.add(rowData);}workbook.close();} catch (Exception e) {// TODO: handle exceptionSystem.out.println(e);}return tpInstallationMaintenanceLabelDetailedList;}}3、List集合数据导入 importInstallationMaintenanceLabelDetailed /*** 导入文件分析*/public String importInstallationMaintenanceLabelDetailed(ListTpInstallationMaintenanceLabelDetailed tpInstallationMaintenanceLabelDetailedList, Boolean isUpdateSupport){if (StringUtils.isNull(tpInstallationMaintenanceLabelDetailedList) || tpInstallationMaintenanceLabelDetailedList.size() 0){throw new ServiceException(导入数据不能为空);}// 执行开始时间Long begin new Date().getTime();// 线程数final int THREAD_COUNT 10;// 每个线程处理的数据量final int BATCH_SIZE tpInstallationMaintenanceLabelDetailedList.size() / THREAD_COUNT;// ExecutorService是Java中对线程池定义的一个接口ExecutorService executor Executors.newFixedThreadPool(THREAD_COUNT);// for (int i 0; i THREAD_COUNT; i) {// List数据开始下标final int startIndex i * BATCH_SIZE;// List数据结束下标final int endIndex (i 1) * BATCH_SIZE;// 线程池执行executor.submit(new Runnable() {public void run() {// 初始化数据库连接对象Connection conn null;// 初始化预编译的 SQL 语句的对象PreparedStatement ps null;try {// 获取连接conn DriverManager.getConnection(jdbc:mysql://localhost:3306/tool_platform_db?useUnicodetruecharacterEncodingutf8zeroDateTimeBehaviorconvertToNulluseSSLtrueserverTimezoneGMT%2B8useSSLfalse, root, 123456);//获取连接// 设置自动提交模式默认trueconn.setAutoCommit(false);// sql前缀String prefix INSERT INTO tp_label_detailed ( account, maintenance_name, county,quality_user, light_cat,wireless_connection, xgpon_onu, light_cat, an_box,two_boxes, three_boxes, an_router, two_routers, three_routers, three_or_more_routers, three_or_more_boxes, severely_and_cats ) VALUES ;// 创建预编译对象ps conn.prepareStatement(prefix);// 保存sql后缀StringBuffer suffix new StringBuffer();// 执行条数int number_of_cycles 0;//for (int j startIndex; j endIndex; j) {// 拼接sqlsuffix.append((tpInstallationMaintenanceLabelDetailedList.get(j).getPppoeAccount(),tpInstallationMaintenanceLabelDetailedList.get(j).getInstallationMaintenanceName(),tpInstallationMaintenanceLabelDetailedList.get(j).getCounty(),tpInstallationMaintenanceLabelDetailedList.get(j).getPoorQualityUser(),tpInstallationMaintenanceLabelDetailedList.get(j).getOldLightCat(),tpInstallationMaintenanceLabelDetailedList.get(j).getSetTopBoxWirelessConnection(),tpInstallationMaintenanceLabelDetailedList.get(j).getPleaseUseXgponOnu(),tpInstallationMaintenanceLabelDetailedList.get(j).getHighTemperatureLightCat(),tpInstallationMaintenanceLabelDetailedList.get(j).getAnOldSetTopBox(),tpInstallationMaintenanceLabelDetailedList.get(j).getTwoOldSetTopBoxes(),tpInstallationMaintenanceLabelDetailedList.get(j).getThreeOldSetTopBoxes(),tpInstallationMaintenanceLabelDetailedList.get(j).getAnPoorQualityRouter(),tpInstallationMaintenanceLabelDetailedList.get(j).getTwoPoorQualityRouters(),tpInstallationMaintenanceLabelDetailedList.get(j).getThreePoorQualityRouters(),tpInstallationMaintenanceLabelDetailedList.get(j).getThreeOrMoreLowQualityRouters(),tpInstallationMaintenanceLabelDetailedList.get(j).getThreeOrMoreOldSetTopBoxes(),tpInstallationMaintenanceLabelDetailedList.get(j).getSeverelyPoorQualityUsersAndOldOpticalCats()),); //拼接sqlnumber_of_cycles number_of_cycles 1;}// sql拼接String sql prefix suffix.substring(0, suffix.length() - 1);// 添加预处理sqlps.addBatch(sql);// 执行语句ps.executeBatch();// 提交conn.commit();// 初始化拼接sqlsuffix.setLength(0);// 初始化条数number_of_cycles 1;} catch (SQLException e) {e.printStackTrace();} finally {if (ps ! null) {try {// 关闭psps.close();} catch (SQLException e) {e.printStackTrace();}}if (conn ! null) {try {// 关闭数据库连接conn.close();} catch (SQLException e) {e.printStackTrace();}}}}});}//关闭线程池,不接受新任务,但会把已添加的任务执行完executor.shutdown();// 等待所有线程完成任务while (!executor.isTerminated()) {} System.out.println(完成);// 结束时间Long end new Date().getTime();// 耗时logger.debug(tpInstallationMaintenanceLabelDetailedList.size()条数据插入花费时间 : (end - begin) / 1000 s);//return 数据导入成功共 tpInstallationMaintenanceLabelDetailedList.size() 条br/数据导入花费时间 : (end - begin) / 1000 s ;}
