如何从一列中分离两个日期 - 从外部文件读取

Question

到目前为止，我已经能够从具有两列的外部 excel 文件中读取。

身份证日期
1 12/12/2018 13/12/2018
2 12/12/2018 13/12/2018
3 12/12/2018 13/12/2018
4 12/12/2018 13/12/2018
5 12/12/2018 13/12/2018
6 12/12/2018 13/12/2018
7 12/12/2018 13/12/2018

我的问题是，有没有什么办法可以将包含两个日期的一列拆分到另一列中，或者用不同的方法将其分开？以上是一个原型，答题法会用在大数据上。如有任何帮助，我们将不胜感激。

目前使用的代码：

package readexcel;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;


public class Readexcel{

@SuppressWarnings({ "unchecked", "unchecked" })
public static void main(String[] args) throws Exception {

//
// An excel file name. You can create a file name with a full
// path information.
//
String filename = "C:\filepath...xls";

//
// Create an ArrayList to store the data read from excel sheet.
//
List sheetData = new ArrayList();
FileInputStream fis = null;
try {
//
// Create a FileInputStream that will be use to read the
// excel file.
//
fis = new FileInputStream(filename);

//
// Create an excel workbook from the file system.
//
HSSFWorkbook workbook = new HSSFWorkbook(fis);
//
// Get the first sheet on the workbook.
//
HSSFSheet sheet = workbook.getSheetAt(0);

//
// When we have a sheet object in hand we can iterator on
// each sheet's rows and on each row's cells. We store the
// data read on an ArrayList so that we can printed the
// content of the excel to the console.
//
Iterator rows = sheet.rowIterator();
while (rows.hasNext()) {
HSSFRow row = (HSSFRow) rows.next();
Iterator cells = row.cellIterator();

List data = new ArrayList();
while (cells.hasNext()) {
HSSFCell cell = (HSSFCell) cells.next();
data.add(cell);
}

sheetData.add(data);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (fis != null) {
fis.close();
}
}

showExcelData(sheetData);
}

private static void showExcelData(List sheetData) {
//
// Iterates the data and print it out to the console.
//
for (int i = 0; i < sheetData.size(); i++) {
List list = (List) sheetData.get(i);
for (int j = 0; j < list.size(); j++) {
Cell cell = (Cell) list.get(j);
if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC) {
System.out.print(cell.getNumericCellValue());
} else if (cell.getCellType() == Cell.CELL_TYPE_STRING) {
System.out.print(cell.getRichStringCellValue());
} else if (cell.getCellType() == Cell.CELL_TYPE_BOOLEAN) {
System.out.print(cell.getBooleanCellValue());
}
if (j < list.size() - 1) {
System.out.print(", ");
}
}
System.out.println("");
}
}
}

Answer 1

    Pattern twoDates = Pattern.compile("(\d+/\d+/\d+)\W+(\d+/\d+/\d+)");
    DateTimeFormatter dateFormatter = DateTimeFormatter.ofPattern("d/M/u");

    String[] dateStrings = {
            "12/12/2018 13/12/2018",
            "12/12/2018-13/12/2018",
            "12/12/2018 - 13/12/2018"
    };
    for (String dateString : dateStrings) {
        Matcher m = twoDates.matcher(dateString);
        if (m.matches()) {
            try {
                String ds1 = m.group(1);
                LocalDate ld1 = LocalDate.parse(ds1, dateFormatter);
                String ds2 = m.group(2);
                LocalDate ld2 = LocalDate.parse(ds2, dateFormatter);
                System.out.println("First date: " + ld1 + " Second date: " + ld2);
            } catch (DateTimeParseException dtpe) {
                System.out.println("Invalid date in string " + dateString
                        + ": " + dtpe.getMessage());
            }
        } else {
            System.out.println("Not two dates: " + dateString);
        }
    }

这输出：

First date: 2018-12-12 Second date: 2018-12-13
First date: 2018-12-12 Second date: 2018-12-13
First date: 2018-12-12 Second date: 2018-12-13

我首先使用正则表达式从字符串中挑选出两个日期。接下来我想使用 LocalDate.parse 来解析和验证日期。您可能想要添加范围检查以进行进一步验证。如果是这样，请使用 LocalDate.isBefore and/or .isAfter.

如何从一列中分离两个日期 - 从外部文件读取

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