Creating PDFs in ASP.NET applications is a common requirement, whether you're generating invoices, reports, forms, or exporting dynamic content. To streamline this process, you can utilize Spire.PDF for .NET, a professional and lightweight library that enables developers to easily create and manipulate PDF documents programmatically, without the need for complex APIs or third-party printer drivers.

In this tutorial, we’ll show you how to create PDF documents in an ASP.NET Core Web application using Spire.PDF for .NET, with examples of creating a PDF from scratch and converting HTML to PDF.

On this page:

• Why Use Spire.PDF for .NET?
• Step-by-Step: Generate PDF in ASP.NET Core Web App
• Create PDF from HTML in ASP.NET Core
• Best Practices for ASP.NET PDF Generation
• Conclusion
• FAQs

Why Use Spire.PDF for .NET?

Step-by-Step: Generate PDF in ASP.NET Core Web App

Step 1. Create a New ASP.NET Core Web App

• Open Visual Studio .
• Select Create a new project .
• Choose ASP.NET Core Web App (Model-View-Controller) → Click Next .
• Enter a project name, e.g., PdfDemoApp.
• Select your target framework (e.g., . NET 6 , 7 , or 8 ).
• Click Create .

Step 2. Install Spire.PDF via NuGet

• Right-click on your project → Manage NuGet Packages .
• Search for Spire.PDF .
• Install the package Spire.PDF (latest stable version).

Or install using the Package Manager Console :

Install-Package Spire.PDF

Step 3. Add a Controller for PDF Generation

• Right-click on the Controllers folder → Add → Controller → MVC Controller – Empty .
• Name it: PdfController.cs.
• Replace the default code with this:

using Microsoft.AspNetCore.Mvc;
using Spire.Pdf;
using Spire.Pdf.Graphics;
using System.Drawing;

namespace PdfDemoApp.Controllers
{
    public class PdfController : Controller
    {
        public IActionResult CreatePdf()
        {
            // Create a new PDF document
            PdfDocument doc = new PdfDocument();
            PdfPageBase page = doc.Pages.Add(PdfPageSize.A4, new PdfMargins(40));

            // Draw text on the page
            PdfFont font = new PdfFont(PdfFontFamily.Helvetica, 25f);
            PdfSolidBrush brush = new PdfSolidBrush(Color.Black);
            page.Canvas.DrawString("Hello from ASP.NET Core!", font, brush, 10, 50);

            // Save to memory stream
            using (MemoryStream ms = new MemoryStream())
            {
                doc.SaveToStream(ms);
                doc.Close();
                ms.Position = 0;

                // Return PDF file
                return File(ms.ToArray(), "application/pdf", "Generated.pdf");
            }
        }
    }
}

Step 4: (Optional) Add a Button or Link in Your View

Open Views/Home/Index.cshtml (or whichever view is your homepage).

Add a button or link like this:

<div>
    <a asp-controller="Pdf" asp-action="CreatePdf" class="btn btn-primary">
        Create PDF from Scratch
    </a>
</div>

This uses ASP.NET Core tag helpers to generate the correct route (/Pdf/CreatePdf).

Step 5. Run and Test

• Press F5 to run your app.
• On the home page, click the "Create PDF from Scratch" button. This will call the CreatePdf method in PdfController and trigger a download of the generated PDF.
• If you didn’t add the button, you can still run the CreatePdf method directly by visiting this URL in your browser:

https://localhost:xxxx/Pdf/CreatePdf

(where xxxx is your local port number).

Output:

In addition to text, Spire.PDF supports adding a wide range of elements to PDF, such as images, shapes, tables, lists, hyperlinks, annotations, and watermarks. For more details and advanced usage, check the .NET PDF Tutorials.

Create PDF from HTML in ASP.NET Core

Spire.PDF allows you to convert HTML content directly into PDF files. This feature is particularly useful for generating invoices, reports, receipts, or exporting styled web pages with consistent formatting.

To render HTML as PDF, Spire.PDF relies on an external rendering engine. You can choose between Qt WebEngine or Google Chrome . In this guide, we’ll use Qt WebEngine .

Setup the Qt plugin:

1. Download the Qt WebEngine plugin for your operating system:

   • Windows x86
   • Windows x64
   • Linux x64
   • Mac x64

2. Extract the package to obtain the plugins directory, e.g.: C:\plugins-windows-x64\plugins

3. Register the plugin path inyour code:

HtmlConverter.PluginPath = @"C:\plugins-windows-x64\plugins";

Once the plugin is ready, you can follow the steps from the previous section and add the code snippet below to your controller to generate PDF output from HTML content.

using Microsoft.AspNetCore.Mvc;
using Spire.Additions.Qt;
using Spire.Pdf.Graphics;
using System.Drawing;

namespace PdfDemoApp.Controllers
{
    public class PdfController : Controller
    {
        [HttpGet]
        public IActionResult HtmlToPdf()
        {
            // Example HTML string
            string html = @"
                <html>
                  <head>
                    <style>
                      body { font-family: Arial, sans-serif; }
                      h1 { color: #2563eb; }
                    </style>
                  </head>
                  <body>
                    <h1>ASP.NET Core: Create PDF from HTML</h1>
                    <p>This PDF was generated using the Qt-based converter.</p>
                  </body>
                </html>";

            // Path to the Qt plugin folder
            // ⚠️ Ensure this folder exists on your server/deployment environment
            string pluginPath = @"C:\plugins-windows-x64\plugins";
            HtmlConverter.PluginPath = pluginPath;

            // Create a temp file path (on server side)
            string tempFile = Path.GetTempFileName();

            // Convert HTML string → PDF using Qt
            HtmlConverter.Convert(
                html,
                tempFile,
                enableJavaScript: true,
                timeout: 100000,                        // milliseconds
                pageSize: new SizeF(595, 842),          // A4 page size in points
                margins: new PdfMargins(40),            // 40pt margins
                LoadHtmlType.SourceCode                 // Load from HTML string
            );

            // Read the generated PDF into memory
            byte[] fileBytes = System.IO.File.ReadAllBytes(tempFile);

            // Clean up temp file
            System.IO.File.Delete(tempFile);

            // Return PDF to browser as download
            return File(fileBytes, "application/pdf", "HtmlToPdf.pdf");
        }
    }
}

Output:

This example converts inline HTML into a properly formatted PDF. You can also load external HTML files or URLs - see our detailed guide on Convert HTML to PDF in C# for more information.

Best Practices for ASP.NET PDF Generation

• Use memory streams instead of disk storage for performance and scalability.
• Cache static PDFs (like terms & conditions or forms) to reduce server load.
• Use HTML-to-PDF for dynamic reports with CSS styling.
• Consider templates (like Word-to-PDF with Spire.Doc) when documents have complex layouts.
• Secure sensitive PDFs with password protection or access permissions.

Conclusion

With Spire.PDF for .NET, you can easily generate PDF in ASP.NET Core applications. Whether you’re creating PDFs from scratch or performing HTML-to-PDF conversion in C# , Spire.PDF provides a reliable, developer-friendly solution—no external dependencies required.

If you also need to generate PDFs from Word documents, that feature is available via Spire.Doc for .NET, another product in the Spire family. Together, they cover the full range of PDF document generation scenarios.

By integrating these tools, developers can streamline workflows, reduce reliance on Adobe or other third-party components, and ensure consistent, professional-quality output. This makes your ASP.NET PDF solutions more scalable, maintainable, and ready for enterprise use.

FAQs

Q1. Do I need Adobe Acrobat installed on the server?

No. Spire.PDF is a standalone library and works independently of Adobe Acrobat.

Q2. Can I generate PDFs from both raw content and HTML?

Yes. You can build documents programmatically (drawing text, shapes, tables) or convert HTML pages to PDF.

Q3. Can I convert Word documents to PDF with Spire.PDF?

No. Word-to-PDF is supported by Spire.Doc for .NET, not Spire.PDF. You can use them together if your project requires it.

Q4. How can I protect generated PDFs?

Spire.PDF supports setting passwords, permissions, and digital signatures for document security.

Q5. Does Spire.PDF support ASP.NET Framework?

Yes. It works with both ASP.NET Core and ASP.NET Framework.

Get a Free License

To fully experience the capabilities of Spire.PDF for .NET without any evaluation limitations, you can request a free 30-day trial license.

HTML (HyperText Markup Language) is a markup language used to create web pages, allowing developers to build rich and visually appealing layouts. However, HTML files often contain a large number of tags, which makes them difficult to read if you only need the main content. By using Python to convert HTML to text, this problem can be easily solved. Unlike raw HTML, the converted text file strips away all unnecessary markup, leaving only clean and readable content that is easier to store, analyze, or process further.

• Install HTML to Text Converter in Python
• Python Convert HTML File to Text
• Python Convert HTML String to Text
• The Conclusion
• FAQs

Install HTML to Text Converter in Python

To simplify the task, we recommend using Spire.Doc for Python. This Python Word library allows you to quickly remove HTML markup and extract clean plain text with ease. It not only works as an HTML-to-text converter, but also offers a wide range of features—covering almost everything you can do in Microsoft Word.

To install it, you can run the following pip command:

pip install spire.doc

Alternatively, you can download the Spire.Doc package and install it manually.

Python Convert HTML Files to Text in 3 Steps

After preparing the necessary tools, let's dive into today's main topic: how to convert HTML to plain text using Python. With the help of Spire.Doc, this task can be accomplished in just three simple steps: create a new document object, load the HTML file, and save it as a text file. It’s straightforward and efficient, even for beginners. Let’s take a closer look at how this process can be implemented in code!

Code Example – Converting an HTML File to a Text File:

from spire.doc import *
from spire.doc.common import *

# Open an html file
document = Document()
document.LoadFromFile("/input/htmlsample.html", FileFormat.Html, XHTMLValidationType.none)
# Save it as a Text document.
document.SaveToFile("/output/HtmlFileTotext.txt", FileFormat.Txt)

document.Close()

The following is a preview comparison between the source document (.html) and the output document (.txt):

Note that if the HTML file contains tables, the output text file will only retain the values within the tables and cannot preserve the original table formatting. If you want to keep certain styles while removing markup, it is recommended to convert HTML to a Word document . This way, you can retain headings, tables, and other formatting, making the content easier to edit and use.

How to Convert an HTML String to Text in Python

Sometimes, we don’t need the entire content of a web page and only want to extract specific parts. In such cases, you can convert an HTML string directly to text. This approach allows you to precisely control the information you need without further editing. Using Python to convert an HTML string to a text file is also straightforward. Here’s a detailed step-by-step guide:

Steps to convert an HTML string to a text document using Spire.Doc:

• Input the HTML string directly or read it from a local file.
• Create a Document object and add sections and paragraphs.
• Use Paragraph.AppendHTML() method to insert the HTML string into a paragraph.
• Save the document as a .txt file using Document.SaveToFile() method.

The following code demonstrates how to convert an HTML string to a text file using Python:

from spire.doc import *
from spire.doc.common import *

#Get html string.
#with open(inputFile) as fp:
    #HTML = fp.read()

# Load HTML from string
html = """<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>HTML to Text Example</title>
  <style>
    body { font-family: Arial, sans-serif; margin: 20px; }
    header { background: #f4f4f4; padding: 10px; }
    nav a { margin: 0 10px; text-decoration: none; color: #333; }
    main { margin-top: 20px; }
  </style>
</head>
<body>
  <header>
    <h1>My Demo Page</h1>
    <nav>
      <a href="#">Home</a>
      <a href="#">About</a>
      <a href="#">Contact</a>
    </nav>
  </header>
  
  <main>
    <h2>Convert HTML to Text</h2>
    <p>This is a simple demo showing how HTML content can be displayed before converting it to plain text.</p>
  </main>
</body>
</html>
"""

# Create a new document
document = Document()
section = document.AddSection()
section.AddParagraph().AppendHTML(html)

# Save directly as TXT
document.SaveToFile("/output/HtmlStringTotext.txt", FileFormat.Txt)
document.Close()

Here's the preview of the converted .txt file:

The Conclusion

In today’s tutorial, we focused on how to use Python to convert HTML to a text file. With the help of Spire.Doc, you can handle both HTML files and HTML strings in just a few lines of code, easily generating clean plain text files. If you’re interested in the other powerful features of the Python Word library, you can request a 30-day free trial license and explore its full capabilities for yourself.

FAQs about Converting HTML to Text in Python

Q1: How can I convert HTML to plain text using Python?

A: Use Spire.Doc to load an HTML file or string, insert it into a Document object with AppendHTML(), and save it as a .txt file.

Q2: Can I keep some formatting when converting HTML to text?

A: To retain styles like headings or tables, convert HTML to a Word document first, then export to text if needed.

Q3: Is it possible to convert only part of an HTML page to text?

A: Yes, extract the specific HTML segment as a string and convert it to text using Python for precise control.

Reading barcodes from PDF in C# is a common requirement in document processing workflows, especially when dealing with scanned forms or digital PDFs. In industries like logistics, finance, healthcare, and manufacturing, PDFs often contain barcodes—either embedded as images or rendered as vector graphics. Automating this process can reduce manual work and improve accuracy.

This guide shows how to read barcode from PDF with C# using two practical methods: extracting images embedded in PDF pages and scanning them, or rendering entire pages as images and detecting barcodes from the result. Both techniques support reliable recognition of 1D and 2D barcodes in different types of PDF documents.

Table of Contents

• Getting Started: Tools and Setup
• Step-by-Step: Read Barcodes from PDF in C#
  • Method 1: Extract Embedded Images and Detect Barcodes
  • Method 2: Render Page as Image and Scan
• Which Method Should You Use?
• Real-World Use Cases
• FAQ

Getting Started: Tools and Setup

To extract or recognize barcodes from PDF documents using C#, make sure your environment is set up correctly.

Here’s what you need:

• Any C# project that supports NuGet package installation (such as .NET Framework, .NET Core, or .NET).
• The following libraries, Spire.Barcode for .NET for barcode recognition and Spire.PDF for .NET for PDF processing, can be installed via NuGet Package Manager:

Install-Package Spire.Barcode
Install-Package Spire.PDF

Step-by-Step: Read Barcodes from PDF in C#

There are two ways to extract barcode data from PDF files. Choose one based on how the barcode is stored in the document.

Method 1: Extract Embedded Images and Detect Barcodes

This method is suitable for scanned PDF documents, where each page often contains a raster image with one or more barcodes. The BarcodeScanner.ScanOne() method can read one barcode from one image.

Code Example: Extract and Scan

using Spire.Barcode;
using Spire.Pdf;
using Spire.Pdf.Utilities;
using System.Drawing;

namespace ReadPDFBarcodeByExtracting
{
    class Program
    {
        static void Main(string[] args)
        {
            // Load a PDF file
            PdfDocument pdf = new PdfDocument();
            pdf.LoadFromFile("Sample.pdf");

            // Get a page and the image information on the page
            PdfPageBase page = pdf.Pages[0];
            PdfImageHelper imageHelper = new PdfImageHelper();
            PdfImageInfo[] imagesInfo = imageHelper.GetImagesInfo(page);

            // Loop through the image information
            int index = 0;
            foreach (PdfImageInfo imageInfo in imagesInfo)
            {
                // Get the image as an Image object
                Image image = imageInfo.Image;
                // Scan the barcode and output the result
                string scanResult = BarcodeScanner.ScanOne((Bitmap)image);
                Console.WriteLine($"Scan result of image {index + 1}:\n" + scanResult + "\n");
                index++;
            }
        }
    }
}

The following image shows a scanned PDF page and the barcode recognition result using Method 1 (extracting embedded images):

When to use: If the PDF is a scan or contains images with embedded barcodes.

You may also like: Generate Barcodes in C# (QR Code Example)

Method 2: Render Page as Image and Scan

When barcodes are drawn using vector elements (not embedded images), you can render each PDF page as a bitmap and perform barcode scanning on it. The BarcodeScanner.Scan() method can read multiple barcodes from one image.

Code Example: Render and Scan

using Spire.Barcode;
using Spire.Pdf;
using System.Drawing;

namespace ReadPDFBarcodeByExtracting
{
    class Program
    {
        static void Main(string[] args)
        {
            // Load a PDF file
            PdfDocument pdf = new PdfDocument();
            pdf.LoadFromFile("Sample.pdf");

            // Save each page as an image
            for (int i = 0; i < pdf.Pages.Count; i++)
            {
                Image image = pdf.SaveAsImage(i);
                // Read the barcodes on the image
                string[] scanResults = BarcodeScanner.Scan((Bitmap)image);
                // Output the results
                for (int j = 0; j < scanResults.Length; j++)
                {
                    Console.WriteLine($"Scan result of barcode {j + 1} on page {i + 1}:\n" + scanResults[j] + "\n");
                }
            }
        }
    }
}

Below is the result of applying Method 2 (rendering full PDF page) to detect vector barcodes on the page:

When to use: When barcodes are drawn on the page directly, not embedded as image elements.

Related article: Convert PDF Pages to Images in C#

Which Method Should You Use?

You can even combine both methods for maximum reliability when handling unpredictable document structures.

Real-World Use Cases

Here are some typical scenarios where barcode recognition from PDFs in C# proves useful:

• Logistics automation Extract tracking numbers and shipping IDs from scanned labels, dispatch forms, or signed delivery receipts in bulk.

• Invoice and billing systems Read barcode-based document IDs or payment references from digital or scanned invoices in batch processing tasks.

• Healthcare document digitization Automatically scan patient barcodes from lab reports, prescriptions, or admission forms in PDF format.

• Manufacturing and supply chain Recognize barcodes from packaging reports, quality control sheets, or equipment inspection PDFs.

• Educational institutions Process barcoded student IDs on scanned test forms or attendance sheets submitted as PDFs.

Tip: In many of these use cases, PDFs come from scanners or online systems, which may embed barcodes as images or page content—both cases are supported with the two methods introduced above.

Conclusion

Reading barcodes from PDF files in C# can be achieved reliably using either image extraction or full-page rendering. Whether you need to extract a barcode from a scanned document or recognize one embedded in PDF content, both methods provide flexible solutions for barcode recognition in C#.

FAQ

Q: Does this work with multi-page PDFs?
Yes. You can loop through all pages in the PDF and scan each one individually.

Q: Can I extract multiple barcodes per page?
Yes. The BarcodeScanner.Scan() method can detect and return all barcodes found on each image.

Q: Can I improve recognition accuracy by increasing resolution?
Yes. When rendering a PDF page to an image, you can set a higher DPI using PdfDocument.SaveAsImage(pageIndex: int, PdfImageType.Bitmap: PdfImageType, dpiX: int, dpiY: int). For example, 300 DPI is ideal for small or low-quality barcodes.

Q: Can I read barcodes from PDF using C# for free?
Yes. You can use Free Spire.Barcode for .NET and Free Spire.PDF for .NET to read barcodes from PDF files in C#. However, the free editions have feature limitations, such as page count or supported barcode types. If you need full functionality without restrictions, you can request a free temporary license to evaluate the commercial editions.

Reading Excel files using Java is a common requirement in enterprise applications, especially when dealing with reports, financial data, user records, or third-party integrations. Whether you're building a data import feature, performing spreadsheet analysis, or integrating Excel parsing into a web application, learning how to read Excel files in Java efficiently is essential.

In this tutorial, you’ll discover how to read .xls and .xlsx Excel files using Java. We’ll use practical Java code examples which also cover how to handle large files, read Excel files from InputStream, and extract specific content line by line.

Table of Contents

• 1. Set Up Your Java Project
• 2. How to Read XLSX and XLS Files in Java
  • Load and Read Excel File (XLSX or XLS)
  • Read Excel File Line by Line
  • Read Excel from InputStream
  • Read Cell Values in Different Formats
• 3. Best Practices for Large Excel Files
• 4. Full Example: Java Program to Read Excel File
• 5. Summary
• 6. FAQ

1. Set Up Your Java Project

To read Excel files using Java, you need a library that supports spreadsheet file formats. Spire.XLS for Java offers support for both .xls (legacy) and .xlsx (modern XML-based) files and provides a high-level API that makes Excel file reading straightforward.

Add Spire.XLS to Your Project

If you're using Maven, add the following to your pom.xml:

<repositories>
    <repository>
        <id>com.e-iceblue</id>
        <name>e-iceblue</name>
        <url>https://repo.e-iceblue.com/nexus/content/groups/public/</url>
    </repository>
</repositories>
<dependencies>
    <dependency>
        <groupId>e-iceblue</groupId>
        <artifactId>spire.xls</artifactId>
        <version>16.7.3</version>
    </dependency>
</dependencies>

If you're not using Maven, you can manually download the JAR from the official Spire.XLS website and add it to your classpath.

For smaller Excel processing tasks, you can also choose Free Spire.XLS for Java.

2. How to Read XLSX and XLS Files in Java

Java programs can easily read Excel files by loading the workbook and iterating through worksheets, rows, and cells. The .xlsx format is commonly used in modern Excel, while .xls is its older binary counterpart. Fortunately, Spire.XLS supports both formats seamlessly with the same code.

Load and Read Excel File (XLSX or XLS)

Here’s a basic example that loads an Excel file and prints its content:

import com.spire.xls.*;

public class ReadExcel {
    public static void main(String[] args) {
        // Create a workbook object and load the Excel file
        Workbook workbook = new Workbook();
        workbook.loadFromFile("data.xlsx"); // or "data.xls"

        // Get the first worksheet
        Worksheet sheet = workbook.getWorksheets().get(0);
        // Loop through each used row and column
        for (int i = 1; i <= sheet.getLastRow(); i++) {
            for (int j = 1; j <= sheet.getLastColumn(); j++) {
                // Get cell text of a cell range
                String cellText = sheet.getCellRange(i, j).getValue();
                System.out.print(cellText + "\t");
            }
            System.out.println();
        }
    }
}

You can replace the file path with an .xls file and the code remains unchanged. This makes it simple to read Excel files using Java regardless of format.

The Excel file being read and the output result shown in the console.

Read Excel File Line by Line with Row Objects

In scenarios like user input validation or applying business rules, processing each row as a data record is often more intuitive. In such cases, you can read the Excel file line by line using row objects via the getRows() method.

for (int i = 0; i < sheet.getRows().length; i++) {
    // Get a row
    CellRange row = sheet.getRows()[i];
    if (row != null && !row.isBlank()) {
        for (int j = 0; j < row.getColumns().length; j++) {
            String text = row.getColumns()[j].getText();
            System.out.print((text != null ? text : "") + "\t");
        }
        System.out.println();
    }
}

This technique works particularly well when reading Excel files in Java for batch operations or when you only need to process rows individually.

Read Excel File from InputStream

In web applications or cloud services, Excel files are often received as streams. Here’s how to read Excel files from an InputStream in Java:

import com.spire.xls.*;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;

public class ReadExcel {
    public static void main(String[] args) throws FileNotFoundException {
        // Create a InputStream
        InputStream stream = new FileInputStream("data.xlsx");
        // Load the Excel file from the stream
        Workbook workbook = new Workbook();
        workbook.loadFromStream(stream);
        System.out.println("Load Excel file successfully.");
    }
}

This is useful when handling file uploads, email attachments, or reading Excel files stored in remote storage.

Read Excel Cell Values in Different Formats

Once you load an Excel file and get access to individual cells, Spire.XLS allows you to read the contents in various formats—formatted text, raw values, formulas, and more.

Here's a breakdown of what each method does:

CellRange cell = sheet.getRange().get(2, 1); // B2

// Formatted text (what user sees in Excel)
String text = cell.getText();

// Raw string value
String value = cell.getValue();

// Generic object (number, boolean, date, etc.)
Object rawValue = cell.getValue2();

// Formula (if exists)
String formula = cell.getFormula();

// Evaluated result of the formula
String result = cell.getEnvalutedValue();

// If it's a number cell
double number = cell.getNumberValue();

// If it's a date cell
java.util.Date date = cell.getDateTimeValue();

// If it's a boolean cell
boolean bool = cell.getBooleanValue();

Tip: Use getValue2() for flexible handling, as it returns the actual underlying object. Use getText() when you want to match Excel's visible content.

You May Also Like: How to Write Data into Excel Files in Java

3. Best Practices for Reading Large Excel Files in Java

When your Excel file contains tens of thousands of rows or multiple sheets, performance can become a concern. To ensure your Java application reads large Excel files efficiently:

• Load only required sheets
• Access only relevant columns or rows
• Avoid storing entire worksheets in memory
• Use row-by-row reading patterns

Here’s an efficient pattern for reading only non-empty rows:

for (int i = 1; i <= sheet.getRows().length; i++) {
    Row row = sheet.getRows()[i];
    if (row != null && !row.isBlank()) {
        // Process only rows with data
    }
}

Even though Spire.XLS handles memory efficiently, following these practices helps scale your Java Excel reading logic smoothly.

See also: Delete Blank Rows and Columns in Excel Using Java

4. Full Example: Java Program to Read Excel File

Here’s a full working Java example that reads an Excel file (users.xlsx) with extended columns such as name, email, age, department, and status. The code extracts only the original three columns (name, email, and age) and filters the output for users aged 30 or older.

import com.spire.xls.*;

public class ExcelReader {
    public static void main(String[] args) {
        Workbook workbook = new Workbook();
        workbook.loadFromFile("users.xlsx");

        Worksheet sheet = workbook.getWorksheets().get(0);
        System.out.println("Name\tEmail\tAge");

        for (int i = 2; i <= sheet.getLastRow(); i++) {
            String name = sheet.getCellRange(i, 1).getValue();
            String email = sheet.getCellRange(i, 2).getValue();
            String ageText = sheet.getCellRange(i, 3).getValue();

            int age = 0;
            try {
                age = Integer.parseInt(ageText);
            } catch (NumberFormatException e) {
                continue;  // Skip rows with invalid age data
            }

            if (age >= 30) {
                System.out.println(name + "\t" + email + "\t" + age);
            }
        }
    }
}

Result of Java program reading the Excel file and printing its contents.

This code demonstrates how to read specific cells from an Excel file in Java and output meaningful tabular data, including applying filters on data such as age.

5. Summary

To summarize, this article showed you how to read Excel files in Java using Spire.XLS, including both .xls and .xlsx formats. You learned how to:

• Set up your Java project with Excel-reading capabilities
• Read Excel files using Java in row-by-row or stream-based fashion
• Handle legacy and modern Excel formats with the same API
• Apply best practices when working with large Excel files

Whether you're reading from an uploaded spreadsheet, a static report, or a stream-based file, the examples provided here will help you build robust Excel processing features in your Java applications.

If you want to unlock all limitations and experience the full power of Excel processing, you can apply for a free temporary license.

6. FAQ

Q1: How to read an Excel file dynamically in Java?

To read an Excel file dynamically in Java—especially when the number of rows or columns is unknown—you can use getLastRow() and getLastColumn() methods to determine the data range at runtime. This ensures that your program can adapt to various spreadsheet sizes without hardcoded limits.

Q2: How to extract data from Excel file in Java?

To extract data from Excel files in Java, load the workbook and iterate through the cells using nested loops. You can retrieve values with getCellRange(row, column).getValue(). Libraries like Spire.XLS simplify this process and support both .xls and .xlsx formats.

Q3: How to read a CSV Excel file in Java?

If your Excel data is saved as a CSV file, you can read it using Java’s BufferedReader or file streams. Alternatively, Spire.XLS supports CSV parsing directly—you can load a CSV file by specifying the separator, such as Workbook.loadFromFile("data.csv", ","). This lets you handle CSV files along with Excel formats using the same API.

Q4: How to read Excel file in Java using InputStream?

Reading Excel files from InputStream in Java is useful in server-side applications, such as handling file uploads. With Spire.XLS, simply call workbook.loadFromStream(inputStream) and process it as you would with any file-based Excel workbook.