现在百度推广有用吗_重庆建筑人员证书查询_网络营销的方式与手段_网络推广与营销

改造后可以在数秒内读取百万级别量的excel数据，注意：csv不行，先转成excel再读取

public class MyBigExcelUtil {/*** 储存表头*/private static List<Object> headLine;/*** 储存返回数据*/private static List<Map<String, Object>> datas = new ArrayList<>();/*** 储存表头行号，默认是第0行*/private static AtomicInteger headNo = new AtomicInteger(0);/*** 设置 表头 行号*/public static void setHeadNo(int headNum) {headNo.set(headNum);}/*** @param pathAndName        文件路径* @param idOrRidOrSheetName Excel中的sheet id或者rid编号或sheet名称，rid必须加rId前缀，例如rId1，如果为-1处理所有编号的sheet*/public static List<Map<String, Object>> readBigExcel(String pathAndName, int idOrRidOrSheetName) {datas.clear();Excel07SaxReader reader = new Excel07SaxReader(new MyRowHandler());reader.read(pathAndName, idOrRidOrSheetName);Console.log("【{}】 读取完成 ... ", pathAndName);return datas;}/*** @param pathAndName        文件路径* @param idOrRidOrSheetName Excel中的sheet id或者rid编号或sheet名称，rid必须加rId前缀，例如rId1，如果为-1处理所有编号的sheet* @param beanType           类类型* @param <T>                返回值为List<T>* @return*/public static <T> List<T> read(String pathAndName, int idOrRidOrSheetName, Class<T> beanType) {return read(pathAndName, idOrRidOrSheetName, beanType, Collections.EMPTY_MAP);}/*** @param pathAndName        文件路径* @param idOrRidOrSheetName Excel中的sheet id或者rid编号或sheet名称，rid必须加rId前缀，例如rId1，如果为-1处理所有编号的sheet, 一般传0* @param beanType           类类型    映射成的实体类* @param fieldMapping       T类型对应的别名，即类类型对应的 excel 的关系   Map<excel列的名字, java中定义实体的字段名>* @param <T>                返回值为List<T>* @return*/public static <T> List<T> read(String pathAndName, int idOrRidOrSheetName, Class<T> beanType, Map<String, String> fieldMapping) {CopyOptions copyOptions = CopyOptions.create();if (CollUtil.isNotEmpty(fieldMapping)) {copyOptions.setFieldMapping(fieldMapping);}readBigExcel(pathAndName, idOrRidOrSheetName);List<T> datalist = new ArrayList<>();for (Map<String, Object> data : datas) {T t = ReflectUtil.newInstanceIfPossible(beanType);datalist.add(BeanUtil.fillBeanWithMap(data, t, copyOptions));}return datalist;}/*** 行数据处理*/private static class MyRowHandler implements RowHandler {@Overridepublic void handle(int sheetIndex, long rowIndex, List<Object> rowList) {//Console.log("[{}] [{}] {}", sheetIndex, rowIndex, rowList);if (rowIndex < headNo.get()) {return;} else if (rowIndex == headNo.get()) {headLine = rowList;} else {Map<String, Object> tMap = new HashMap<>(rowList.size());for (int i = 0; i < headLine.size(); i++) {Object key = headLine.get(i);Object val = rowList.get(i);tMap.put(key == null ? "" : key.toString(), val == null ? "" : val);}datas.add(tMap);}}}
}