Repository Configuration

If the default Maven repositories fail to resolve Aspose artifacts, explicitly configure the official source in your project settings:

<repositories>
    <repository>
        <id>aspose-java-repo</id>
        <url>https://releases.aspose.com/java/repo</url>
        <snapshots>
            <enabled>false</enabled>
        </snapshots>
    </repository>
</repositories>

Core Dependencies

Word Processor Support

Include the following dependency for DOC and DOCX handling:

<dependency>
    <groupId>com.aspose</groupId>
    <artifactId>aspose-words</artifactId>
    <version>20.12</version>
    <type>pom</type>
</dependency>

Spreadsheeet Support

For XLS and XLSX formats:

<dependency>
    <groupId>com.aspose</groupId>
    <artifactId>aspose-cells</artifactId>
    <version>20.12</version>
</dependency>

Presentation Support

Required for PPT and PPTX processing:

<dependency>
    <groupId>com.aspose</groupId>
    <artifactId>aspose-slides</artifactId>
    <version>20.12</version>
    <classifier>jdk16</classifier>
</dependency>

Implementation Patterns

The following utility class demonstrates converting uploaded files into InputStream instances containing PDF data. This approach centralizes logic to reduce code duplication.

import com.aspose.words.Document;
import com.aspose.words.License;
import com.aspose.words.SaveFormat;
import com.aspose.cells.PdfSaveOptions;
import com.aspose.cells.Workbook;
import com.aspose.slides.Presentation;
import org.springframework.web.multipart.MultipartFile;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;

public class DocumentConversionUtils {

    /**
     * Transforms a Word document into a binary PDF stream.
     */
    public static InputStream transformWordToPdf(MultipartFile file) throws Exception {
        try (ByteArrayOutputStream buffer = new ByteArrayOutputStream()) {
            Document doc = new Document(file.getInputStream());
            doc.save(buffer, SaveFormat.PDF);
            return new ByteArrayInputStream(buffer.toByteArray());
        }
    }

    /**
     * Transforms an Excel spreadsheet into a binary PDF stream.
     */
    public static InputStream transformExcelToPdf(MultipartFile file) throws Exception {
        try (ByteArrayOutputStream buffer = new ByteArrayOutputStream()) {
            Workbook workbook = new Workbook(file.getInputStream());
            PdfSaveOptions pdfConfig = new PdfSaveOptions();
            pdfConfig.setOnePagePerSheet(true);
            workbook.save(buffer, pdfConfig);
            return new ByteArrayInputStream(buffer.toByteArray());
        }
    }

    /**
     * Transforms a PowerPoint presentation into a binary PDF stream.
     */
    public static InputStream transformPptToPdf(MultipartFile file) throws Exception {
        try (ByteArrayOutputStream buffer = new ByteArrayOutputStream()) {
            Presentation pres = new Presentation(file.getInputStream());
            pres.save(buffer, SaveFormat.Pdf);
            return new ByteArrayInputStream(buffer.toByteArray());
        }
    }
}

Licensing and Watermarks

Free versions of the library generate watermarked output. To remove this limitation, obtain a valid license key or XML file. Place this file in your src/main/resources directory.

import com.aspose.words.License;
import java.io.InputStream;

public void loadLicense() {
    try {
        ClassLoader loader = Thread.currentThread().getContextClassLoader();
        InputStream licStream = loader.getResourceAsStream("license.xml");
        if (licStream != null) {
            License license = new License();
            license.setLicense(licStream);
        }
    } catch (Exception e) {
        // Handle missing license configuration
    }
}