使用POI Apache从Excel读取数据时向ArrayList添加数据

Posted 2021-03-27

我正在尝试使用POI Apache从Excel工作表中读取数据。我遇到的问题是我想同时读取行中所有单元格的数据并将其存储在Type Class的ArrayList中，但输出只是逐个单元格。

这是打开Excel工作表并按单元格逐个读取数据的类。

package testing;

import javax.swing.JFileChooser;
import java.io.File;
import java.io.FileInputStream;

import java.io.FileOutputStream;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
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.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class ReadExcelDemo 
{
    ArrayList<Data> list = new ArrayList<>();
    String path;

   public ReadExcelDemo(String path)
   {
       this.path = path;

        try
        {
            FileInputStream file = new FileInputStream(new File(path));

            //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);

             System.out.println("");

            //Iterate through each rows one by one
            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
                    switch (cell.getCellType()) 
                    {
                        case Cell.CELL_TYPE_NUMERIC:
                            System.out.print(cell.getNumericCellValue() + "	");

                            break;
                        case Cell.CELL_TYPE_STRING:
                            System.out.print(cell.getStringCellValue() + "	");
                            break;
                    }
                }


                System.out.println("");
            }
            file.close();
        } 
        catch (Exception e) 
        {
            e.printStackTrace();
        }
    }
}

数据类

package testing;


public class Data {


    int ID;
    String F_Name,L_Name;




    public Data(int ID, String F_Name, String L_Name) {
        this.ID = ID;
        this.F_Name = F_Name;
        this.L_Name = L_Name;
    }


    public int getID() {
        return ID;
    }

    public String getF_Name() {
        return F_Name;
    }

    public String getL_Name() {
        return L_Name;
    }

我想一次在这样的Arraylist中添加单元格数据

List.add(new Data(1,"Amit","shukla"));

但迭代器返回的数据是逐个输出1然后输出amit然后shukla，这真的很难添加到arraylist

我尝试过将数据添加到ArrayList的单行，但我做不到。如果你的家伙帮我解决这个问题，那将会非常有帮助。

答案

this.path = path;

    try
    {
        FileInputStream file = new FileInputStreaHashMap<K, V>ile(path));
        HashMap<Integer, Data> mp= new HashMap<Integer, Data>();
        //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);

         System.out.println("");

        //Iterate through each rows one by one
        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
                int i=0;
                int j=0;
                switch (cell.getCellType()) 
                {
                    case Cell.CELL_TYPE_NUMERIC:
                        System.out.print(cell.getNumericCellValue() + "	");
                            i=Integer.parseInt(cell.getNumericCellValue());
                            Data d= new Data();
                            d.setId(cell.getNumericCellvalue());


                        break;
                    case Cell.CELL_TYPE_STRING:
                        System.out.print(cell.getStringCellValue() + "	");
                        if( j==0){
                        Data data= mp.get(i);
                        data.setName(cell.getStringCellValue());
                        mp.put(i, data);
                        j=j+1;
                        }
                        else
                        {
                            Data data= mp.get(i);
                            data.setLastName(cell.getStringCellValue());
                            mp.put(i, data);
                            j=0;
                        }
                        break;
                }
            }


            System.out.println("");
        }
        List<Data> dataList=  new ArrayList<Data>();
        for (Data d : mp.values()) {
           dataList.add(d);

        }
        file.close();
    } 
    catch (Exception e) 
    {
        e.printStackTrace();
    }

另一答案

您可以使用此方法通过单次迭代添加Excel的单行，

public void ReadExcel(String filePath,String fileName,String sheetName) throws InterruptedException, IOException{
    File file = new File(filePath+""+fileName);
    //Create an object of FileInputStream class to read excel file
    FileInputStream inputStream = new FileInputStream(file);
    Workbook AddCatalog = null;
    //Find the file extension by splitting file name in substring  and getting only extension name
    String fileExtensionName = fileName.substring(fileName.indexOf("."));
    //Check condition if the file is a .xls file or .xlsx file
    if(fileExtensionName.equals(".xls")){
        //If it is .xls file then create object of HSSFWorkbook class
        AddCatalog = new HSSFWorkbook(inputStream);
    }
    else if(fileExtensionName.equals(".xlsx")){
        //If it is .xlsx file then create object of XSSFWorkbook class
        AddCatalog = new XSSFWorkbook(inputStream);
    }
    //Read sheet inside the workbook by its name
    Sheet AddCatalogSheet = AddCatalog.getSheet(sheetName);
    //Find number of rows in excel file
    int rowcount = AddCatalogSheet.getLastRowNum()- AddCatalogSheet.getFirstRowNum();
    System.out.println("Total row number: "+rowcount);
    for(int i=1; i<rowcount+1; i++){
        //Create a loop to get the cell values of a row for one iteration
        Row row = AddCatalogSheet.getRow(i);
        List<String> arrName = new ArrayList<String>();
        for(int j=0; j<row.getLastCellNum(); j++){
            // Create an object reference of 'Cell' class
            Cell cell = row.getCell(j);
            // Add all the cell values of a particular row
            arrName.add(cell.getStringCellValue());
            }
        System.out.println(arrName);
        System.out.println("Size of the arrayList: "+arrName.size());
        // Create an iterator to iterate through the arrayList- 'arrName'
        Iterator<String> itr = arrName.iterator();
        while(itr.hasNext()){
            System.out.println("arrayList values: "+itr.next());
        }
        }

}

另一答案

您在Switch和Case中遇到问题部件更改应该可以正常工作：

   switch (cell.getCellType())  {
         case NUMERIC:
               System.out.print(cell.getNumericCellValue() + "	");
               break;
        case STRING:
              System.out.print(cell.getStringCellValue() + "	");
              break;
      }