When drawing text on PDF page, you can align text horizontally and vertically. This tutorial will show you how to align text in a line and a rectangle by using Spire.PDF for Java.

Align Text in Line

import com.spire.pdf.graphics.*;

import java.awt.*;

public class AlignTextInLine {

    public static void main(String[] args) {

        //create a PdfDocument object 
        PdfDocument doc = new PdfDocument();

        //add a page 
        PdfPageBase page = doc.getPages().add();

        //create a true type font
        PdfTrueTypeFont font= new PdfTrueTypeFont(new Font("Times New Roman",Font.PLAIN,15));

        //create a brush 
        PdfSolidBrush brush = new PdfSolidBrush(new PdfRGBColor(Color.black));

        //create a PdfStringFormat object, specifying PdfTextAlignment to Left
        PdfStringFormat leftAlignment = new PdfStringFormat(PdfTextAlignment.Left);

        //draw text at left 
        page.getCanvas().drawString("Left", font , brush, 0, 20, leftAlignment);

        //draw text at right 
        PdfStringFormat rightAlignment = new PdfStringFormat(PdfTextAlignment.Right);
        page.getCanvas().drawString("Right", font , brush, page.getCanvas().getClientSize().getWidth(), 20, rightAlignment);

        //draw text in center 
        PdfStringFormat centerAlignment = new PdfStringFormat(PdfTextAlignment.Center);
        page.getCanvas().drawString("Center", font , brush, page.getCanvas().getClientSize().getWidth() / 2, 20, centerAlignment);

        //save the file 
        doc.saveToFile("AlignTextInLine.pdf");
    }
}

Output:

Align Text in Rectangle

import com.spire.pdf.graphics.*;

import java.awt.*;
import java.awt.geom.Rectangle2D;

public class AlignTextInRectangle {

    public static void main(String[] args) {

        //create a PdfDocument object 
        PdfDocument doc = new PdfDocument();

        //add a page 
        PdfPageBase page = doc.getPages().add();

        //create a true type font
        PdfTrueTypeFont font= new PdfTrueTypeFont(new Font("Times New Roman",Font.PLAIN,15));

        //craete a pen 
        PdfPen pen = new PdfPen(new PdfRGBColor(Color.black));

        //create a brush 
        PdfSolidBrush brush = new PdfSolidBrush(new PdfRGBColor(Color.black));

        //draw a rectangle 
        Rectangle2D.Float rect = new Rectangle2D.Float();
        rect.setRect(0, 20, page.getCanvas().getClientSize().getWidth() / 2, 100);
        page.getCanvas().drawRectangle(pen, rect);

        //create a PdfStringFormat object, specifying PdfTextAlignment to Top and Left
        PdfStringFormat topLeft = new PdfStringFormat(PdfTextAlignment.Left, PdfVerticalAlignment.Top);

        //draw text at top left
        page.getCanvas().drawString("TopLeft", font, brush, rect, topLeft);

        //draw text at top right 
        PdfStringFormat topRight = new PdfStringFormat(PdfTextAlignment.Right, PdfVerticalAlignment.Top);
        page.getCanvas().drawString("TopRight", font, brush, rect, topRight);

        //draw text in center 
        PdfStringFormat center = new PdfStringFormat(PdfTextAlignment.Center, PdfVerticalAlignment.Middle);
        page.getCanvas().drawString("Center", font, brush, rect, center);

        //draw text at bottom left 
        PdfStringFormat bottomLeft = new PdfStringFormat(PdfTextAlignment.Left, PdfVerticalAlignment.Bottom);
        page.getCanvas().drawString("BottomLeft", font, brush, rect, bottomLeft);

        //draw text at bottom right 
        PdfStringFormat bottomRight = new PdfStringFormat(PdfTextAlignment.Right, PdfVerticalAlignment.Bottom);
        page.getCanvas().drawString("BottomRight", font, brush, rect, bottomRight);

        //save the file 
        doc.saveToFile("AlignTextInRectangle.pdf");
    }
}

Output:

A table represents information or data in the form of horizontal rows and vertical columns. Creating tables is often more efficient than describing the data in the paragraph text, especially when the data is numerical or large. The tabular data presentation makes it easier to read and understand. In this article, you will learn how to create tables in a PDF document in Java using Spire.PDF for Java.

Spire.PDF for Java offers the PdfTable and the PdfGrid class to work with the tables in a PDF document. The PdfTable class is used to quickly create simple, regular tables without too much formatting, while the PdfGrid class is used to create more complex tables.

The table below lists the differences between these two classes.

The following sections demonstrate how to create a table in PDF using the PdfTable class and the PdfGrid class, respectively.

• Create a Table in PDF Using PdfTable Class
• Create a Table in PDF Using PdfGrid Class

Install Spire.PDF for Java

First of all, you're required to add the Spire.Pdf.jar file as a dependency in your Java program. The JAR file can be downloaded from this link. If you use Maven, you can easily import the JAR file in your application by adding the following code to your project's pom.xml file.

<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.pdf</artifactId>
        <version>11.10.3</version>
    </dependency>
</dependencies>

Create a Table in PDF Using PdfTable Class

The following are the steps to create a table using the PdfTable class using Spire.PDF for Java.

• Create a PdfDocument object.
• Add a page to it using PdfDocument.getPages().add() method.
• Create a Pdftable object.
• Set the table style using the methods under PdfTableStyle object which is returned by PdfTable.getTableStyle() method.
• Insert data to table using PdfTable.setDataSource() method.
• Set row height and row color through BeginRowLayout event.
• Draw table on the PDF page using PdfTable.draw() method.
• Save the document to a PDF file using PdfDocument.saveToFile() method.

import com.spire.data.table.DataTable;
import com.spire.pdf.PdfDocument;
import com.spire.pdf.PdfPageBase;
import com.spire.pdf.PdfPageSize;
import com.spire.pdf.graphics.*;
import com.spire.pdf.tables.*;

import java.awt.*;
import java.awt.geom.Point2D;

public class CreateTable {

    public static void main(String[] args) {

        //Create a PdfDocument object
        PdfDocument doc = new PdfDocument();

        //Add a page
        PdfPageBase page = doc.getPages().add(PdfPageSize.A4, new PdfMargins(40));

        //Create a PdfTable object
        PdfTable table = new PdfTable();

        //Set font for header and the rest cells
        table.getStyle().getDefaultStyle().setFont(new PdfTrueTypeFont(new Font("Times New Roman", Font.PLAIN, 12), true));
        table.getStyle().getHeaderStyle().setFont(new PdfTrueTypeFont(new Font("Times New Roman", Font.BOLD, 12), true));

        //Define data
        String[] data = {"ID;Name;Department;Position;Level",
                "1; David; IT; Manager; 1",
                "3; Julia; HR; Manager; 1",
                "4; Sophie; Marketing; Manager; 1",
                "7; Wickey; Marketing; Sales Rep; 2",
                "9; Wayne; HR; HR Supervisor; 2",
                "11; Mia; Dev; Developer; 2"};
        String[][] dataSource = new String[data.length][];
        for (int i = 0; i < data.length; i++) {
            dataSource[i] = data[i].split("[;]", -1);
        }

        //Set data as the table data
        table.setDataSource(dataSource);

        //Set the first row as header row
        table.getStyle().setHeaderSource(PdfHeaderSource.Rows);
        table.getStyle().setHeaderRowCount(1);

        //Show header(the header is hidden by default)
        table.getStyle().setShowHeader(true);

        //Set font color and background color of header row
        table.getStyle().getHeaderStyle().setBackgroundBrush(PdfBrushes.getGray());
        table.getStyle().getHeaderStyle().setTextBrush(PdfBrushes.getWhite());

        //Set text alignment in header row
        table.getStyle().getHeaderStyle().setStringFormat(new PdfStringFormat(PdfTextAlignment.Center, PdfVerticalAlignment.Middle));

        //Set text alignment in other cells
        for (int i = 0; i < table.getColumns().getCount(); i++) {
            table.getColumns().get(i).setStringFormat(new PdfStringFormat(PdfTextAlignment.Center, PdfVerticalAlignment.Middle));
        }

        //Register with BeginRowLayout event
        table.beginRowLayout.add(new BeginRowLayoutEventHandler() {

            public void invoke(Object sender, BeginRowLayoutEventArgs args) {
                Table_BeginRowLayout(sender, args);

            }
        });

        //Draw table on the page
        table.draw(page, new Point2D.Float(0, 30));

        //Save the document to a PDF file
        doc.saveToFile("output/PdfTable.pdf");

    }

    //Event handler
    private static void Table_BeginRowLayout(Object sender, BeginRowLayoutEventArgs args) {

        //Set row height
        args.setMinimalHeight(20f);

        //Alternate color of rows except the header row
        if (args.getRowIndex() == 0) {
            return;
        }
        if (args.getRowIndex() % 2 == 0) {
            args.getCellStyle().setBackgroundBrush(PdfBrushes.getLightGray());
        } else {
            args.getCellStyle().setBackgroundBrush(PdfBrushes.getWhite());
        }
    }
}

Create a Table in PDF Using PdfGrid Class

Below are the steps to create a table in PDF using the PdfGrid class using Spire.PDF for Java.

• Create a PdfDocument object.
• Add a page to it using PdfDocument.getPages().add() method.
• Create a PdfGrid object.
• Set the table style using the methods under the PdfGridStyle object which is returned by PdfGrid.getStyle() method.
• Add rows and columns to the table using PdfGrid.getRows().add() method and PdfGrid.getColumns().add() method.
• Insert data to specific cells using PdfGridCell.setValue() method.
• Span cells across columns or rows using PdfGridCell.setRowSpan() method or PdfGridCell.setColumnSpan() method.
• Set the formatting of a specific cell using PdfGridCell.setStringFormat() method and the methods under PdfGridCellStyle object.
• Draw table on the PDF page using PdfGrid.draw() method.
• Save the document to a PDF file using PdfDocument.saveToFile() method.

import com.spire.pdf.*;
import com.spire.pdf.graphics.*;
import com.spire.pdf.grid.PdfGrid;
import com.spire.pdf.grid.PdfGridRow;

import java.awt.*;
import java.awt.geom.Point2D;

public class CreateGrid {

    public static void main(String[] args) {

        //Create a PdfDocument object
        PdfDocument doc = new PdfDocument();

        //Add a page
        PdfPageBase page = doc.getPages().add(PdfPageSize.A4,new PdfMargins(40));

        //Create a PdfGrid
        PdfGrid grid = new PdfGrid();

        //Set cell padding
        grid.getStyle().setCellPadding(new PdfPaddings(1, 1, 1, 1));

        //Set font
        grid.getStyle().setFont(new PdfTrueTypeFont(new Font("Times New Roman", Font.PLAIN, 13), true));

        //Add rows and columns
        PdfGridRow row1 = grid.getRows().add();
        PdfGridRow row2 = grid.getRows().add();
        PdfGridRow row3 = grid.getRows().add();
        PdfGridRow row4 = grid.getRows().add();
        grid.getColumns().add(4);

        //Set column width
        for (int i = 0; i < grid.getColumns().getCount(); i++) {

            grid.getColumns().get(i).setWidth(120);
        }

        //Write data into specific cells
        row1.getCells().get(0).setValue("Order and Payment Status");
        row2.getCells().get(0).setValue("Order number");
        row2.getCells().get(1).setValue("Date");
        row2.getCells().get(2).setValue ("Customer");
        row2.getCells().get(3).setValue("Paid or not");
        row3.getCells().get(0).setValue("00223");
        row3.getCells().get(1).setValue("2022/06/02");
        row3.getCells().get(2).setValue("Brick Lane Realty");
        row3.getCells().get(3).setValue("Yes");
        row4.getCells().get(0).setValue("00224");
        row4.getCells().get(1).setValue("2022/06/03");
        row4.getCells().get(3).setValue("No");

        //Span cell across columns
        row1.getCells().get(0).setColumnSpan(4);

        //Span cell across rows
        row3.getCells().get(2).setRowSpan(2);

        //Set text alignment of specific cells
        row1.getCells().get(0).setStringFormat(new PdfStringFormat(PdfTextAlignment.Center));
        row3.getCells().get(2).setStringFormat(new PdfStringFormat(PdfTextAlignment.Left, PdfVerticalAlignment.Middle));

        //Set background color of specific cells
        row1.getCells().get(0).getStyle().setBackgroundBrush(PdfBrushes.getOrange());
        row4.getCells().get(3).getStyle().setBackgroundBrush(PdfBrushes.getLightGray());

        //Format cell border
        PdfBorders borders = new PdfBorders();
        borders.setAll(new PdfPen(new PdfRGBColor(Color.ORANGE), 0.8f));
        for (int i = 0; i < grid.getRows().getCapacity(); i++) {

            PdfGridRow gridRow = grid.getRows().get(i);
            gridRow.setHeight(20f);
            for (int j = 0; j < gridRow.getCells().getCount(); j++) {
                gridRow.getCells().get(j).getStyle().setBorders(borders);
            }

        }

        //Draw table on the page
        grid.draw(page, new Point2D.Float(0, 30));

        //Save the document to a PDF file
        doc.saveToFile("output/PdfGrid.pdf");
    }
}

Apply for a Temporary License

If you'd like to remove the evaluation message from the generated documents, or to get rid of the function limitations, please request a 30-day trial license for yourself.

Merging PDFs in Java is a critical requirement for document-intensive applications, from consolidating financial reports to automating archival systems. However, developers face significant challenges in preserving formatting integrity or managing resource efficiency across diverse PDF sources. Spire.PDF for Java provides a robust and straightforward solution to streamline the PDF merging task.

This comprehensive guide explores how to combine PDFs in Java, complete with practical examples to merge multiple files, selected pages, or stream-based merging.

• Setting Up the Java PDF Merge Library
• Merge Multiple PDF Files in Java
• Merge Specific Pages from Multiple PDFs in Java
• Merge PDF Files by Streams in Java
• Conclusion
• FAQs

Setting Up the Java PDF Merge Library

Why Choose Spire.PDF for Java?

• No External Dependencies: Pure Java implementation.
• Rich Features: Merge, split, encrypt, and annotate PDFs.
• Cross-Platform: Works on Windows, Linux, and macOS.

Installation

Before using Spire.PDF for Java, you need to add it to your project.

Option 1: Maven

Add the repository and dependency to 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.pdf</artifactId>
        <version>11.10.3</version>
    </dependency>
</dependencies>

Option 2: Manual JAR

Download the JAR from the E-iceblue website and add it to your project's build path.

Merge Multiple PDF Files in Java​

This example is ideal when you want to merge two or more PDF documents entirely. It’s simple, straightforward, and perfect for batch processing.

How It Works:​

• Define File Paths: Create an array of strings containing the full paths to the source PDFs.​
• Merge Files: The mergeFiles() method takes the array of paths, combines the PDFs, and returns a PdfDocumentBase object representing the merged file.​
• Save the Result: The merged PDF is saved to a new file using the save() method.​

Java code to combine PDFs:

import com.spire.pdf.FileFormat;
import com.spire.pdf.PdfDocument;
import com.spire.pdf.PdfDocumentBase;

public class MergePdfs {
    public static void main(String[] args) {

        // Get the paths of the PDF documents to be merged 
        String[] files = new String[] {"sample-1.pdf", "sample-2.pdf", "sample-3.pdf"};

        // Merge these PDF documents
        PdfDocumentBase pdf = PdfDocument.mergeFiles(files);

        // Save the merged PDF file
        pdf.save("MergePDF.pdf", FileFormat.PDF);
    }
}

Best For:​

• Merging entire PDFs stored locally.​
• Simple batch operations where no page selection is needed.

Result: Combine three PDF files (a total of 10 pages) into one PDF file.

Merging PDFs often results in large file sizes. To reduce the size, refer to: Compress PDF Files in Java.

Merge Specific Pages from Multiple PDFs in Java

Sometimes, you may only want to merge specific pages from different PDFs (e.g., pages 1-3 from File A and pages 2-5 from File B). This example gives you granular control over which pages to include from each source PDF.

How It Works:​

• Load PDFs: Load each source PDF into a PdfDocument object and store them in an array.​
• Create a New PDF: A blank PDF document is initialized to serve as the container for merged pages.​
• Insert Specific Pages:​
  • insertPage(): Insert a specified page into the new PDF.​
  • insertPageRange(): Inserts a range of pages into the new PDF.
• Save the Result: The merged PDF is saved using the saveToFile() method.​

Java code to combine selected PDF pages:

import com.spire.pdf.PdfDocument;

public class MergeSelectedPages {

    public static void main(String[] args) {

        // Get the paths of the PDF documents to be merged
        String[] files = new String[] {"sample-1.pdf", "sample-2.pdf", "sample-3.pdf"};

        // Create an array of PdfDocument
        PdfDocument[] pdfs = new PdfDocument[files.length];

        // Loop through the documents
        for (int i = 0; i < files.length; i++)
        {
            // Load a specific document
            pdfs[i] = new PdfDocument(files[i]);
        }

        // Create a new PDF document
        PdfDocument pdf = new PdfDocument();

        // Insert the selected pages from different PDFs to the new PDF
        pdf.insertPage(pdfs[0], 0);
        pdf.insertPageRange(pdfs[1], 1,3);
        pdf.insertPage(pdfs[2], 0);

        // Save the merged PDF
        pdf.saveToFile("MergePdfPages.pdf");
    }
}

Best For:​

• Creating custom PDFs with selected pages (e.g., extracting key sections from reports).​
• Scenarios where you need to exclude irrelevant pages from source documents.

Result: Combine selected pages from three separate PDF files into a new PDF

Merge PDF Files by Streams in Java

In applications where PDFs are stored as streams (e.g., PDFs from network streams, in-memory data, or temporary files), Spire.PDF supports merging without saving files to disk.

How It Works:​

• Create Input Streams: The FileInputStream objects read the raw byte data of each PDF file.​
• Merge Streams: The mergeFiles() method accepts an array of streams, merges them, and returns a PdfDocumentBase object.​
• Save and Clean Up: The merged PDF is saved, and all streams and documents are closed to free system resources (critical for preventing leaks).​

Java code to merge PDFs via streams:

import com.spire.pdf.*;
import java.io.*;

public class mergePdfsByStream {
    public static void main(String[] args) throws IOException {
        // Create FileInputStream objects for each PDF document file
        FileInputStream stream1 = new FileInputStream(new File("Template_1.pdf"));
        FileInputStream stream2 = new FileInputStream(new File("Template_2.pdf"));
        FileInputStream stream3 = new FileInputStream(new File("Template_3.pdf"));

        // Initialize an array of InputStream objects containing the file input streams
        InputStream[] streams = new FileInputStream[]{stream1, stream2, stream3};

        // Merge the input streams into a single PdfDocumentBase object
        PdfDocumentBase pdf = PdfDocument.mergeFiles(streams);

        // Save the merged PDF file
        pdf.save("MergePdfsByStream.pdf", FileFormat.PDF);

        // Releases system resources used by the merged document
        pdf.close();
        pdf.dispose();

        // Closes all input streams to free up resources
        stream1.close();
        stream2.close();
        stream3.close();
    }
}

Best For:​

• Merging PDFs from non-file sources (e.g., network downloads, in-memory generation).​
• Environments where direct file path access is restricted.

Conclusion

Spire.PDF for Java simplifies complex PDF merging tasks through its intuitive, user-friendly API. Whether you need to merge entire documents, create custom page sequences, or combine PDFs from stream sources, these examples enable efficient PDF merging in Java to address diverse document processing requirements.

To explore more features (e.g., encrypting merged PDFs, adding bookmarks), refer to the official documentation.

Frequently Asked Questions (FAQs)

Q1: Why do merged PDFs show "Evaluation Warning" watermarks?

A: The commercial version adds watermarks. Solutions:

• Request a 30-day trial license to test without any restrictions.
• Use the free version for documents ≤10 pages

Q2: How do I control the order of pages in the merged PDF?

A: The order of pages in the merged PDF is determined by the order of input files (or streams) and the pages you select. For example:

• In full-document merging, files in the input array are merged in the order they appear.
• In selective page merging, use insertPage() or insertPageRange() in the sequence you want pages to appear.

Q3: Can I merge password-protected PDFs?

A: Yes. Spire.PDF for Java supports merging encrypted PDFs, but you must provide the password when loading the file. Use the overloaded loadFromFile() method with the password parameter:

PdfDocument pdf = new PdfDocument();
pdf.loadFromFile("sample.pdf", "userPassword"); // Decrypt with password

Q4: How to merge scanned/image-based PDFs?

A: Spire.PDF handles image-PDFs like regular PDFs, but file sizes may increase significantly.