This Java code reads data from an Excel spreadsheet file. It iterates through each row and cell of the first sheet in the file. For each cell, it gets the cell type and value, and prints it to the console. It handles numeric and string cell types separately. Any headers or column names in the first row are stored in a HashMap to label the values from subsequent rows.

1. import java.io.File;
import java.io.FileInputStream;
import java.util.HashMap;
import java.util.Iterator;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public class ReadExcelDemo
{
public static void main(String[] args)
{
try
{
FileInputStream file = new FileInputStream(new
File("ValidateCVDeviceByObligationDomain.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);
//Iterate through each rows one by one
Iterator<Row> rowIterator = sheet.iterator();
int count =0;
HashMap <String,String> hn = new HashMap<String, String>();
while (rowIterator.hasNext())
{
Row row = rowIterator.next();
count++;
int cell_count=0;
//For each row, iterate through all the columns
Iterator<Cell> cellIterator = row.cellIterator();
while (cellIterator.hasNext())
{
Cell cell = cellIterator.next();
String content = null;
//Check the cell type and format accordingly
cell_count++;
if(count==1)
{
switch (cell.getCellType())
{
case Cell.CELL_TYPE_NUMERIC:
content=String.valueOf(cell.getNumericCellValue());
//System.out.print(cell.getNumeri
cCellValue() + "t");
break;
case Cell.CELL_TYPE_STRING:
content=cell.getStringCellValue();
//System.out.print(cell.getString
CellValue() + "t");
break;
}
/*System.out.println("cell_count

2. "+cell_count);
*
System.out.println("content "+content);*/
hn.put(String.valueOf(cell_count), content);
}
else
{
//ystem.out.println("in else cell_count
"+cell_count);
switch (cell.getCellType())
{
case Cell.CELL_TYPE_NUMERIC:
//content=String.valueOf(cell.get
NumericCellValue());
System.out.print(hn.get(String.valueOf(cell_count))
+cell.getNumericCellValue() + "t");
break;
case Cell.CELL_TYPE_STRING:
content=cell.getStringCellValue();
System.out.print(hn.get(String.valueOf(cell_count))
+cell.getStringCellValue() + "t");
break;
}
}
}
System.out.println("");
}
file.close();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}