Posts Tagged ‘Data type’

The Java programming language is a strongly-typed language and it consist of eight primitive data types (byte, short, int, long, float, double, boolean, char). For more about java primitive data type, please visit http://java.sun.com/docs/books/tutorial/java/nutsandbolts/datatypes.html

Well, sometime we really need to know what is the limit of the primitive types in java. With following simple code, we can print out the limit of each of the java primitive data types (except boolean and char) 🙂

public class PrintTypeLimit
{
    public static void main(String args[]) {        System.out.println("Min byte value   = " + Byte.MIN_VALUE);
        System.out.println("Max byte value   = " + Byte.MAX_VALUE);
        System.out.println("Min short value  = " + Short.MIN_VALUE);
        System.out.println("Max short value  = " + Short.MAX_VALUE);
        System.out.println("Min int value    = " + Integer.MIN_VALUE);
        System.out.println("Max int value    = " + Integer.MAX_VALUE);
        System.out.println("Min long value    = " + Long.MIN_VALUE);
        System.out.println("Max long value    = " + Long.MAX_VALUE);
        System.out.println("Min float value  = " + Float.MIN_VALUE);
        System.out.println("Max float value  = " + Float.MAX_VALUE);
        System.out.println("Min double value = " + Double.MIN_VALUE);
        System.out.println("Max double value = " + Double.MAX_VALUE);
    }
}

 

Output

Min byte value   = -128
Max byte value   = 127
Min short value  = -32768
Max short value  = 32767
Min int value    = -2147483648
Max int value    = 2147483647
Min long value    = -9223372036854775808
Max long value    = 9223372036854775807
Min float value  = 1.4E-45
Max float value  = 3.4028235E38
Min double value = 4.9E-324
Max double value = 1.7976931348623157E308

 

Dock icon for Excel 2011 for Mac

Hi last evening i am worry about the thing that i delete data from Cell of the Excel file but when i retrieving data and displaying it was showing me that cell from which i delete data as “null” and that is the Problem for Me …….. Now for that I solve it like that ………

In this example we try to obtain the Excel’s cell data type so that we can read the value using the right method. The data to be read is contained in a file named celltype.xls. The below matrix depict how to file is look like.

    |   COL
ROW |   0       1   2   3   4
----|-------------------------
0   |   1       2   A   B   TRUE
1   |   FALSE   X   Y   Z   10
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package org.kodejava.example.poi;
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 java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.Iterator;
public class ObtainingCellType {
    public static void main(String[] args) throws Exception {
        String filename = "..\\celltype.xls";
        FileInputStream fis = null;
        try {
            fis = new FileInputStream(filename);
            HSSFWorkbook workbook = new HSSFWorkbook(fis);
            HSSFSheet sheet = workbook.getSheetAt(0);
            Iterator rows = sheet.rowIterator();
            while (rows.hasNext()) {
                HSSFRow row = (HSSFRow) rows.next();
                Iterator cells = row.cellIterator();
                while (cells.hasNext()) {
                    HSSFCell cell = (HSSFCell) cells.next();
                    int type = cell.getCellType();
                    if (type == HSSFCell.CELL_TYPE_STRING) {
                        System.out.println("[" + cell.getRowIndex() + ", "
                                + cell.getColumnIndex() + "] = STRING; Value = "
                                + cell.getRichStringCellValue().toString());
                    } else if (type == HSSFCell.CELL_TYPE_NUMERIC) {
                        System.out.println("[" + cell.getRowIndex() + ", "
                                + cell.getColumnIndex() + "] = NUMERIC; Value = "
                                + cell.getNumericCellValue());
                    } else if (type == HSSFCell.CELL_TYPE_BOOLEAN) {
                        System.out.println("[" + cell.getRowIndex() + ", "
                                + cell.getColumnIndex() + "] = BOOLEAN; Value = "
                                + cell.getBooleanCellValue());
                    } else if (type == HSSFCell.CELL_TYPE_BLANK) {
                        System.out.println("[" + cell.getRowIndex() + ", "
                                + cell.getColumnIndex() + "] = BLANK CELL");
                    }
                }
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } finally {
            if (fis != null) {
                fis.close();
            }
        }
    }
}

Our program iterates the Excel file rows and cells and produce the following output:

[0, 0] = NUMERIC; Value = 1.0
[0, 1] = NUMERIC; Value = 2.0
[0, 2] = STRING; Value = A
[0, 3] = STRING; Value = B
[0, 4] = BOOLEAN; Value = true
[1, 0] = BOOLEAN; Value = false
[1, 1] = STRING; Value = X
[1, 2] = STRING; Value = Y
[1, 3] = STRING; Value = Z
[1, 4] = NUMERIC; Value = 10.0