How to Read Excel Files in Java (1).pdf

How to Read Excel Files in
Java?
In today’s computer world, excel files are an integral part of every business ranging
from small to large. The uses of Excel files include data management, analysis,
charting, graphing, etc. So when we come to the programming side, there will be a
situation where we have to handle Excel files. In Java programming, there is no
built-in feature to support Excel files. Yet we can handle Excel files easily by using
the third-party API named Apache POI. In today’s article, we will look at how to read
Excel files in Java using the Apache POI API.
Excel files:
We all know that Excel files are spreadsheets that make data handling and
manipulation easier.
Generally, there are two file formats available for Excel files. They are
1. .xls
2. .xlsx.
The xls format is the older one for 2003 and older versions. And xlsx is a new format
for excel 2007 and later.
Apache POI:

Generally, Apache POI (Poor Obfuscation Implementation) is an open-source library
for handling Microsoft office related files. Java does not have the built-in feature to
handle excel files. So, We use Apache POI, a third-party Java API with classes and
interfaces to deal with reading and writing operations in excel files.
This API supports both .xls and .xlsx formats. To deal with the .xls format, we use
HSSF(Horrible SpreadSheet Format) implementation. And to deal with the .xlsx
format, we use XSSF(XML SpreadSheet Format) implementation.
Classes:
We all know that Excel files consist of Workbook, WorkSheets, cells, rows, and
columns. The API comprises a variety of classes to incorporate the functionality that
deals with excel files. There are separate classes available to deal with .xls and .xlsx
formats.
HSSFWorkbook, HSSFSheet, HSSFRow, and HSSFCell are the classes that
provide the functionality for handling workbooks, sheets, rows, and cells in xls format
files, respectively.
Similarly, the XSSFWorkbook, XSSFSheet, XSSFRow, and XSSFCell are the
classes that provide the functionality for handling workbooks, sheets, rows, and cells
in xlsx format files, respectively.
Interface:
This API provides some common interfaces for all the classes discussed above.
They are:

1. Workbook – Workbook is a common interface implemented by both
HSSFWorkbook and XSSFWorkbook classes.
2. Sheet – The HSSFSheet and XSSFSheet classes implement this interface.
3. Row – Both HSSFRow and XSSFRow classes use this interface.
4. Cell – The HSSFCell and XSSFCell classes implement this interface.
Prerequisites for using ApachePOI to
read excel file in java:
The requirements for using ApachePOI are:
1. An eclipse IDE
2. poi-bin-5.2.3-20220909.zip folder
Extract the zip file. There is a list of jar files required to use ApachePOI.
You can download the latest versions of the jar if needed.
3. An excel file in both formats.
a. In this article, we will use the excel files named FirstCode.xls and FirstCode.xlsx.
b. The content of the files are:
Now follow the steps given below to set up the environment.
1. Open the Eclipse IDE
2. Create a new java project.

3. Add all the downloaded jar files in the classpath, as shown below.
Right-click the project name→ Build Path → Configure Build Path → Click the
libraries tab → Add External jars in Classpath → Select all the jars discussed above
→ Click Apply and close. If you are using maven, you should include the following
dependencies in your pom.xml file.
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>5.2.0</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>5.2.0</version>
</dependency>
Code to read the xls file in java:
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.Scanner;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.FormulaEvaluator;
import org.apache.poi.ss.usermodel.Row;
public class ReadExcelFile {
public static void main(String args[])
{
try {
//Creating a file object and getting the excel file.
File file= new File("E:FirstCode.xls");
// Creating FileInputStream object to read the file.
FileInputStream fisObject=new FileInputStream(file);
//Creating Workbook instance for .xls file.
HSSFWorkbook workbook=new HSSFWorkbook(fisObject);
//Getting the sheet number from the user.
System.out.println("Enter the sheet number:");
Scanner scan = new Scanner(System.in);
int sheetnumber = scan.nextInt();
//Creating a Sheet object to get the required sheet in the file.
HSSFSheet sheet=workbook.getSheetAt(sheetnumber);
//Evaluating cell type
FormulaEvaluator
formulaEvaluator=workbook.getCreationHelper().createFormulaEvaluator();
//Iterating the rows with, for each loop.

for(Row row: sheet)
{
//Iterating the cells with, for each loop.
for(Cell cell: row)
{
switch(formulaEvaluator.evaluateInCell(cell).getCellType())
{
//Numeric cell type.
case NUMERIC:
//Getting the cell value as a number and printing it.
System.out.print(cell.getNumericCellValue()+ "tt");
break;
//String cell type.
case STRING:
//Getting the cell value as a string and printing it.
System.out.print(cell.getStringCellValue()+ "tt");
break;
default:
break;
}
}
System.out.println();
}

workbook.close();
}
catch(FileNotFoundException exception) {
//If there is no excel file with the given name found in the specified location, it
throws FileNotFoundException.
System.out.println("File Not Found.");
}
catch(IllegalArgumentException exception) {
//If the sheet is empty, it throws an IllegalArgumentException.
System.out.println("Sheet is empty");
}
catch(Exception exception) {
//To deal with other Exceptions.
exception.printStackTrace();
}
}
}
Output:
■ When the excel file reading is successful, whole file will be displayed as
output.
■ When there is no excel file with the given name found in the specified
location, the output will be:
File Not Found
■ When there is no data in the given sheet index, the output will be:

Sheet is empty
Code to read the xlsx file in java:
import java.util.Iterator;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public class ReadExcelFile
{
public static void main(String[] args)
{
try
{
//Creating a file object and getting the excel file.
File file = new File("E:FirstCode.xlsx");
FileInputStream fisObject = new FileInputStream(file);
//Creating Workbook instance for .xlsx file.

XSSFWorkbook workbook = new XSSFWorkbook(fisObject);
System.out.println("Enter the sheet number:");
XSSFSheet sheet = workbook.getSheetAt(sheetnumber);
//Using an iterator to iterate the sheet object to get rows.
Iterator<Row> itr = sheet.iterator();
while (itr.hasNext())
{
// Getting the row values.
Row row = itr.next();
//Iterating each column in the row.
Iterator<Cell> cellIterator = row.cellIterator();
while (cellIterator.hasNext())
{
//Getting column values.
Cell cell = cellIterator.next();
//Getting cell type.
switch (cell.getCellType())
{
//String cell type.

case STRING:
//Getting the cell value as a string and printing it.
System.out.print(cell.getStringCellValue() + "ttt");
break;
//Numeric cell type.
case NUMERIC:
//Getting the cell value as a number and printing it.
System.out.print(cell.getNumericCellValue() + "ttt");
break;
default:
break;
}
}
System.out.println("");
}
workbook.close();
}
catch(FileNotFoundException exception)
{
}

catch(IllegalArgumentException exception)
{
}
catch(Exception exception)
{
}
}
}
Output:
■ When the excel file reading is successful, the output will be the whole file.
File Not Found
Sheet is Empty
Code to read a particular cell value in the
xlsx file in Java:

import java.io.IOException;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
public static void main(String[] args)
{
//Creating an object for the ReadExcelFile class.
ReadExcelFile rc=new ReadExcelFile();
System.out.println("Enter the sheet, row, and column number of the cell:");
//Getting the input for sheet, row, and column number, from the user.
int row = scan.nextInt();
int column = scan.nextInt();
//ReadCellData function call
String vOutput=rc.ReadCellData(row, column, sheetnumber);
//Checking whether the return value is null. The method returns null when the sheet or
cell is empty.

if(vOutput!=null)
//Printing the cell value.
System.out.println(vOutput);
}
//Method for getting the cell value.
public String ReadCellData(int vRow, int vColumn, int vsheet)
{
//Variable to store the cell value.
String value=null;
//Initializing Workbook object as null.
Workbook workbook=null;
try
{
FileInputStream fis=new FileInputStream("E:FirstCode.xlsx");
//Creating Workbook instance for .xls file.
workbook=new XSSFWorkbook(fis);
Sheet sheet=workbook.getSheetAt(vsheet);
// Getting the specified row.
Row row=sheet.getRow(vRow);
// Getting the specified column.
Cell cell=row.getCell(vColumn);

// Getting the specified cell value.
value=cell.getStringCellValue();
}
{
}
catch(IOException exception)
{
System.out.println("Invalid inputs.");
}
catch(NullPointerException exception)
{
//If the cell is empty, it throws a NullPointerException.
System.out.println("No data in the specified cell");
}
{
System.out.println("Empty sheet");
}

{
}
// Returns the corresponding cell value.
return value;
}
}
Output:
■ When the excel file reading is successful, the output will be the desired
value.
File Not Found
Empty Sheet
■ When there is no data in the given cell, the output will be:
No data in the specified cell
Code to read xls and xlsx files in java:

import org.apache.poi.ss.usermodel.DataFormatter;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.usermodel.WorkbookFactory;
public static final String FILE_PATH = "E:FirstCode.xlsx";
public static void main(String[] args) {
try {
//Creating Workbook instance for excel file for both format .xls and .xlsx file.
Workbook workbook = WorkbookFactory.create(new File(FILE_PATH));
// Getting the number of sheets in the Workbook.
System.out.println("Workbook consists of " + workbook.getNumberOfSheets() + " Sheets :
");
System.out.println("Enter the sheet index number:");
Sheet sheet = workbook.getSheetAt(sheetnumber);
// Create a DataFormatter to format each cell value as String.
DataFormatter dataFormatter = new DataFormatter();
//Using forEach loop with lambda(Java8).

sheet.forEach(row -> {
row.forEach(cell -> {
String cellValue = dataFormatter.formatCellValue(cell);
System.out.print(cellValue + "tt");
});
System.out.println();
});
// Closing the workbook object.
workbook.close();
}
{
}
{
}
{

}
}
}
Output:
■ When the excel file reading is successful, the output will be as desired.
■ When there is no Excel file with the given name found in the specified
File not Found
Sheet is Empty
Additional tips:
If your excel file has more than one sheet, you can get the number of sheets and
iterate over them. Refer to the code snippet for a better understanding.
Code snippet:
workbook.forEach(sheet -> {
System.out.println("=> " + sheet.getSheetName());
});
To iterate among the sheets or rows, or cells, you can use one of the following ways:
1. for each loop with a lambda expression.

2. for each loop
3. Iterator
I demonstrated each iterating way in the sample codes above for your reference.
Summary
There is another API for handling excel files named JXL or JEXCEL. But this API
supports only xls files and does not support xlsx files. Its last update was in 2009. So
everyone uses ApachePOI now. I hope you understand how to use ApachePOI to
read excel files in java. Thank you for reading.

How to Read Excel Files in Java (1).pdf

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How to Read Excel Files in Java (1).pdf