Jotenberg

A Java library that interacts with Gotenberg's different modules to convert a variety of document formats to PDF files.

Snippets

To incorporate jotenberg into your project, follow the snippets below for Apache Maven and Gradle dependencies.

Apache Maven

<dependency>
    <groupId>dev.inaka</groupId>
    <artifactId>jotenberg</artifactId>
    <version>1.0.2</version>
</dependency>

Gradle

implementation group: 'dev.inaka', name: 'jotenberg', version: '1.0.2'

Prerequisites

Before attempting to use Jotenberg, be sure you install Docker if you have not already done so.

Once the docker Daemon is up and running, you can start a default Docker container of Gotenberg as follows:

docker run --rm -p 8090:8090 gotenberg/gotenberg:7 gotenberg --api-port=8090

After that, you need to download the latest Jotenberg JAR library from the GitHub Releases page and add it to your Java project classpath.

Get Started

Create an instance of Jotenberg class and pass your Gotenberg endpoint url as a constructor parameter.

Jotenberg client = new Jotenberg("http://localhost:8090/");

Chormium

Jotenberg client comes with a convert method that calls one of Chromium's routes to convert html and markdown files, or a url to a CloseableHttpResponse that contains the HttpEntity which holds the content of the converted PDF file.

convert expects two parameters; the first parameter represents what will be converted (i.e. url, html, or markdown files), and the second one is a PageProperties parameter.

URL

CloseableHttpResponse response = client.convert("https://gotenberg.dev/", pageProperties);

HTML

The only requirement is that the file name should be index.html.

File file = new File("path/to/index.html");
CloseableHttpResponse response = client.convert(file, pageProperties);

Markdown

This route accepts an index.html file plus markdown files.

List<File> files = new ArrayList<>();

files.add(new File("path/to/index.html"));
files.add(new File("path/to/markdown.md"));

CloseableHttpResponse response = client.convert(files, pageProperties);

Customization

Jotenberg client comes with PageProperties which is a builder class that allows you to customize the style of the generated PDF. The default page properties can be found here.

PageProperties pageProperties = new PageProperties.Builder().build();

Libre Office

Jotenberg client provides a convertWithLibreOffice method which interacts with LibreOffice to convert different types of documents such as .docx, .epub, .eps, and so on. You can find the list of all file extensions here.

List<File> files = new ArrayList<>();

files.add(new File("path/to/file.docx"));
files.add(new File("path/to/file.xlsx"));

CloseableHttpResponse response = client.convertWithLibreOffice(files, pageProperties);

PDF Engines

Similarly, Jotenberg client provides a convertWithPdfEngines method which interacts with PDF Engines to convert PDF files to a specific format (i.e. PDF/A-1a, PDF/A-2b, PDF/A-3b)).

The supported formats can be found in PdfFormat.

List<File> files = new ArrayList<>();

files.add(new File("path/to/first.pdf"));
files.add(new File("path/to/second.pdf"));

PageProperties pageProperties = new PageProperties.Builder()
                                                    .addPdfFormat(PdfFormat.A_3B.format())
                                                    .build();

CloseableHttpResponse response = client.convertWithPdfEngines(files, pageProperties);

Additionally, you can also use merge method to alphabetically merge the PDF files.

List<File> files = new ArrayList<>();

files.add(new File("path/to/first.pdf"));
files.add(new File("path/to/second.pdf"));

CloseableHttpResponse response = client.merge(files, pageProperties);

Example

The following is a short snippet of how to use the library.

import dev.inaka.Jotenberg;
import dev.inaka.common.PageProperties;
import org.apache.commons.io.FileUtils;

import java.nio.file.Files;
import java.nio.file.Paths;

public class Main {
    public static void main(String[] args) {
        try (var client = new Jotenberg("http://localhost:80/")) {
            var url = "https://gotenberg.dev/";
            var properties = new PageProperties.Builder()
                    .addMarginTop(1.0f)
                    .addMarginLeft(0.5f)
                    .addMarginBottom(1.0f)
                    .addMarginTop(0.5f)
                    .addPrintBackground(true)
                    .build();
            var response = client.convert(url, properties);
            var projectDir = Paths.get("").toAbsolutePath().normalize();
            var tempDir = Files.createTempDirectory(projectDir, "temp_");
            var tempFile = Files.createTempFile(tempDir, "PDF_", ".pdf").toFile();
            var pdfContent = response.getEntity().getContent();
            FileUtils.copyInputStreamToFile(pdfContent, tempFile);
        } catch (Exception e) {
            throw new RuntimeException(e);
        }

    }
}