Converting file streams to PDF/UA

Applications don’t always receive documents as file paths. A document might already be open as a file stream when it reaches a conversion service.

This sample converts a PDF supplied through a FileInputStream into a PDF/UA document written through a FileOutputStream. Keeping the conversion stream-based avoids reopening the input and output through SDK file-path overloads.

Preparing the project

Specify a package name and import the SDK and Java I/O classes used by the sample:

package io.nutrient.Sample;

import io.nutrient.sdk.Document;
import io.nutrient.sdk.enums.PdfConformance;
import io.nutrient.sdk.settings.PdfSettings;

import java.io.FileInputStream;
import java.io.FileOutputStream;

public class ConvertFromFileStreamToPdfUa {

Create the entry point and open the input file, output file, and document in a try-with-resources statement. Keep the input stream open for the lifetime of the document. Java closes the document before it closes either stream.

    public static void main(String[] args) {
        try (FileInputStream inputStream = new FileInputStream("input.pdf");
             FileOutputStream outputStream = new FileOutputStream("output.pdf");
             Document document = Document.open(inputStream)) {

Converting file streams to PDF/UA

Set PDF/UA-1 conformance and pass the output stream to exportAsPdf():

            PdfSettings pdfSettings = document.getSettings().getPdfSettings();
            pdfSettings.setConformance(PdfConformance.PDF_UA_1);

            document.exportAsPdf(outputStream);
            System.out.println("Successfully converted the file stream to PDF/UA.");
        } catch (Exception e) {
            System.err.println("Failed to convert the file stream to PDF/UA: " + e.getMessage());
            System.exit(1);
        }
    }
}

Document.open(FileInputStream) reads the source through the supplied stream. exportAsPdf(FileOutputStream) writes the converted document through the supplied output stream. Both streams remain owned by the application and are closed by the try-with-resources statement.

Error handling

The sample catches exceptions from Java file operations and SDK document processing. It writes an error message and returns a nonzero exit code when either operation fails.

Conclusion

The sample opens a PDF from a FileInputStream, applies PDF/UA-1 conformance settings, and writes the converted document to a FileOutputStream.

Download this ready-to-use sample package.