Question

我正在尝试从excel读取数据，并希望在Java中为标题和值创建Map。

我可以使用Java读取数据，但是我不想跳过空值，因为我需要创建标头和值的hashmap，即使它是空的。

Iterator<Row> rowIterator = sheet.iterator();
while (rowIterator.hasNext()) {
    Row row = rowIterator.next();
    //For each row, iterate through all the columns
    Iterator<Cell> cellIterator = row.cellIterator();

    while (cellIterator.hasNext())
    {
         Cell cell = cellIterator.next();
        //Check the cell type and format accordingly
        //System.out.println(cell.getCellType());

        if(cell.getCellType() == Cell.CELL_TYPE_NUMERIC) 
        {
            System.out.print(cell.getNumericCellValue() + ";");
        }
        if(cell.getCellType() == Cell.CELL_TYPE_STRING) 
        {
            System.out.print(cell.getStringCellValue() + ";");
        }
        if(cell.getCellType() == Cell.CELL_TYPE_BLANK) 
        {
            System.out.print("Blank");
        }
    }
    System.out.println("");
}
file.close();

attr_item_code;tag_warranty;MASTER;1032839;MASTER

我要为上述数据创建一个hashmap

{
  "attr_item_code":"1032839",
   "tag_warranty":"",
   "MASTER":"MASTER"
}

Answer 1

尝试一下：

        Iterator<Row> rowIterator = sheet.iterator();
        boolean isHeader = true;
        HashMap<String, ArrayList<String>> data = new HashMap<String, ArrayList<String>>();
        HashMap<Integer, String> headers = new HashMap<Integer, String>();

        while (rowIterator.hasNext()) {
            Row row = rowIterator.next();
            // For each row, iterate through all the columns
            Iterator<Cell> cellIterator = row.cellIterator();
            int rowNum = 1;
            while (cellIterator.hasNext()) {
                Cell cell = cellIterator.next();

                if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC) {
                    if (isHeader) {
                        data.put(String.valueOf(cell.getNumericCellValue()), new ArrayList<String>());
                        headers.put(rowNum, String.valueOf(cell.getNumericCellValue()));
                    } else {
                        ArrayList<String> tmp = data.get(headers.get(rowNum));
                        tmp.add(String.valueOf(cell.getNumericCellValue()));
                        data.put(headers.get(rowNum), tmp);
                    }
                    System.out.print(cell.getNumericCellValue() + ";");
                } else if (cell.getCellType() == Cell.CELL_TYPE_STRING) {
                    if (isHeader) {
                        data.put(cell.getStringCellValue(), new ArrayList<String>());
                        headers.put(rowNum, cell.getStringCellValue());
                    } else {
                        ArrayList<String> tmp = data.get(headers.get(rowNum));
                        tmp.add(cell.getStringCellValue());
                        data.put(headers.get(rowNum), tmp);
                    }
                } else if (cell.getCellType() == Cell.CELL_TYPE_BLANK) {
                    if (isHeader) {
                        data.put("", new ArrayList<String>());
                        headers.put(rowNum, "");
                    } else {
                        ArrayList<String> tmp = data.get(headers.get(rowNum));
                        tmp.add("");
                        data.put(headers.get(rowNum), tmp);
                    }
                }
                rowNum++;
            }
            if (isHeader) {
                isHeader = false;
            }
        }
        file.close();

Answer 2

如果column1或column2中有空行，则（cellIterator.hasNext（））将跳过空单元格。您最终将毫无头绪。因此，您已经更改了读取文件的方式。

您最好使用列索引读取excel文件。

示例代码（未编译）。

while (rowIterator.hasNext()) {
    Row row = rowIterator.next();
    if (row != null) {

        // 1st cell
        Cell cell1 = row.getCell(1);

        // 2nd cell
        Cell cell2 = row.getCell(2);

        // 3rd cell
        Cell cell3 = row.getCell(3);
        ...... so on 

        // you know the cell type so read accordingly 

        // cell1.getNumericCellValue() or cell1.getStringCellValue() etc
        }
        }

Answer 3

import java.io.File;
import java.io.FileInputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import com.fasterxml.jackson.databind.ObjectMapper;

public class ReadExcelDemo1 
{

    public static void main(String[] args)
    {
        try
        {
            String header="";
            FileInputStream file = new FileInputStream(new File("C:/Talend/Testing/master_old.xlsx"));

            //Create Workbook instance holding reference to .xlsx file
            XSSFWorkbook workbook = new XSSFWorkbook(file);

            //Get first/desired sheet from the workbook
            XSSFSheet sheet = workbook.getSheetAt(0);

            Iterator<Row> rowIterator = sheet.iterator();
            boolean isHeader = true;

            //HashMap<String,Object> masterMap = new HashMap<String,Object>();
            List<Object> masterList = new ArrayList<Object>();
            HashMap<String, ArrayList<String>> masterData = new HashMap<String, ArrayList<String>>();
            HashMap<Integer, String> headers = new HashMap<Integer, String>();

            //int rowStart = sheet.getFirstRowNum();
            //int rowEnd = sheet.getLastRowNum();

            int rowStart = sheet.getFirstRowNum();
            int rowEnd = sheet.getPhysicalNumberOfRows();
            //System.out.println(sheet.getFirstRowNum() + " - ---------------"+sheet.getLastRowNum());

            for (int rowNum = rowStart; rowNum <= rowStart; rowNum++) 
            {
                Row r = sheet.getRow(rowNum);
                int lastColumn = r.getLastCellNum();
                for (int cn = 0; cn < lastColumn; cn++) 
                {
                    Cell cell = r.getCell(cn);
                    if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC) 
                    {
                        int value = (int) Math.round(cell.getNumericCellValue());
                        masterData.put(String.valueOf(value), new ArrayList<String>());
                        headers.put(cn, String.valueOf(value));
                    }
                    else if (cell.getCellType() == Cell.CELL_TYPE_STRING) 
                    {
                        masterData.put(String.valueOf(cell.getStringCellValue()), new ArrayList<String>());
                        headers.put(cn, String.valueOf(cell.getStringCellValue()));
                    }
                }
            }


            for (int rowNum = rowStart + 1; rowNum <= rowEnd; rowNum++) 
            {
                HashMap<String, Object> data = new HashMap<String, Object>();

                Row r = sheet.getRow(rowNum);
                if (r == null) 
                {
                    // This whole row is empty
                    // Handle it as needed
                    continue;
                 }
                int lastColumn = r.getLastCellNum();

                for (int cn = 0; cn < lastColumn; cn++) 
                {
                   //Cell cell = r.getCell(cn, Row.RETURN_BLANK_AS_NULL);
                   Cell cell = r.getCell(cn);
                   if(cell != null) 
                   {
                       if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC) 
                       {
                          String headerValue = headers.get(cn);
                          List<String> tmp = new ArrayList<>();
                          int value = (int) Math.round(cell.getNumericCellValue());
                          tmp.add(String.valueOf(value));
                          data.put(headerValue, tmp);

                       } 
                       else if (cell.getCellType() == Cell.CELL_TYPE_STRING) 
                       {
                           String headerValue = headers.get(cn);
                           List<String> tmp = new ArrayList<>();
                           String strValue = String.valueOf(cell.getStringCellValue());
                           if(headerValue.startsWith("taxo_") || headerValue.startsWith("tag_") || headerValue.equals("MASTER"))
                           {
                               data.put(headerValue, Arrays.asList(strValue.split(",")));
                           }
                           else
                           {
                               tmp.add(String.valueOf(cell.getStringCellValue()));
                               data.put(headerValue, tmp);
                           }


                       } 
                       else if (cell.getCellType() == Cell.CELL_TYPE_BLANK)
                       {
                           String headerValue = headers.get(cn);
                           List<String> tmp = new ArrayList<>();
                           data.put(headerValue, tmp);  
                       }
                   }
                   else 
                   {
                       String headerValue = headers.get(cn);
                       List<String> tmp = new ArrayList<>();
                       data.put(headerValue, tmp);
                   }

                }
                masterList.add(data);

            }

            System.out.println(new ObjectMapper().writeValueAsString(masterList));
            //System.out.println(new ObjectMapper().writeValueAsString(headers));
            file.close();
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }   
}

如何使用Java替换Excel的空白单元格

3 个答案: