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Java

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Extract text, tables, images, and metadata from 91+ file formats including PDF, Office documents, and images. Java bindings with type-safe API, Foreign Function & Memory API integration, and native performance.

Installation

Package Installation

Install via one of the supported package managers:

Maven:

<dependency>
    <groupId>dev.kreuzberg</groupId>
    <artifactId>kreuzberg</artifactId>
    <version>4.6.3</version>
</dependency>

Gradle:

implementation 'dev.kreuzberg:kreuzberg:4.6.3'

System Requirements

  • Java 11+ required
  • Optional: ONNX Runtime version 1.22.x for embeddings support
  • Optional: Tesseract OCR for OCR functionality

Quick Start

Basic Extraction

Extract text, metadata, and structure from any supported document format:

import dev.kreuzberg.Kreuzberg;
import dev.kreuzberg.ExtractionResult;
import java.io.IOException;
import java.util.Map;

public class BasicUsage {
    public static void main(String[] args) throws IOException {
        ExtractionResult result = Kreuzberg.extractFile("document.pdf");

        System.out.println("Content:");
        System.out.println(result.getContent());

        System.out.println("\nMetadata:");
        Map<String, Object> metadata = result.getMetadata();
        if (metadata != null) {
            System.out.println("Title: " + metadata.get("title"));
            System.out.println("Author: " + metadata.get("author"));
        }

        System.out.println("\nTables found: " + result.getTables().size());
        System.out.println("Images found: " + result.getImages().size());
    }
}

Common Use Cases

Extract with Custom Configuration

Most use cases benefit from configuration to control extraction behavior:

With OCR (for scanned documents):

import dev.kreuzberg.Kreuzberg;
import dev.kreuzberg.ExtractionResult;
import dev.kreuzberg.KreuzbergException;
import dev.kreuzberg.config.ExtractionConfig;
import dev.kreuzberg.config.OcrConfig;
import java.io.IOException;

public class Main {
    public static void main(String[] args) {
        try {
            ExtractionConfig config = ExtractionConfig.builder()
                .ocr(OcrConfig.builder()
                    .backend("tesseract")
                    .language("eng")
                    .build())
                .build();

            ExtractionResult result = Kreuzberg.extractFile("scanned.pdf", config);
            System.out.println(result.getContent());
        } catch (IOException | KreuzbergException e) {
            System.err.println("Extraction failed: " + e.getMessage());
        }
    }
}

Table Extraction

See Table Extraction Guide for detailed examples.

Processing Multiple Files

import dev.kreuzberg.Kreuzberg;
import dev.kreuzberg.ExtractionResult;
import dev.kreuzberg.KreuzbergException;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

try {
    List<String> files = Arrays.asList("doc1.pdf", "doc2.docx", "doc3.pptx");

    List<ExtractionResult> results = Kreuzberg.batchExtractFiles(files, null);

    for (int i = 0; i < results.size(); i++) {
        ExtractionResult result = results.get(i);
        System.out.println("File " + (i + 1) + ": " + result.getContent().length() + " characters");
    }
} catch (IOException | KreuzbergException e) {
    e.printStackTrace();
}

Async Processing

For non-blocking document processing:

import dev.kreuzberg.Kreuzberg;
import dev.kreuzberg.ExtractionResult;
import java.nio.file.Path;
import java.util.concurrent.CompletableFuture;

public class Example {
    public static void main(String[] args) {
        CompletableFuture<ExtractionResult> future =
            Kreuzberg.extractFileAsync(Path.of("document.pdf"), null);

        future.thenAccept(result -> {
            System.out.println(result.getContent());
            System.out.println("Tables: " + result.getTables().size());
        }).join();
    }
}

Next Steps

Features

Supported File Formats (91+)

91+ file formats across 8 major categories with intelligent format detection and comprehensive metadata extraction.

Office Documents

Category Formats Capabilities
Word Processing .docx, .docm, .dotx, .dotm, .dot, .odt Full text, tables, images, metadata, styles
Spreadsheets .xlsx, .xlsm, .xlsb, .xls, .xla, .xlam, .xltm, .xltx, .xlt, .ods Sheet data, formulas, cell metadata, charts
Presentations .pptx, .pptm, .ppsx, .potx, .potm, .pot, .ppt Slides, speaker notes, images, metadata
PDF .pdf Text, tables, images, metadata, OCR support
eBooks .epub, .fb2 Chapters, metadata, embedded resources
Database .dbf Table data extraction, field type support
Hangul .hwp, .hwpx Korean document format, text extraction

Images (OCR-Enabled)

Category Formats Features
Raster .png, .jpg, .jpeg, .gif, .webp, .bmp, .tiff, .tif OCR, table detection, EXIF metadata, dimensions, color space
Advanced .jp2, .jpx, .jpm, .mj2, .jbig2, .jb2, .pnm, .pbm, .pgm, .ppm OCR via hayro-jpeg2000 (pure Rust decoder), JBIG2 support, table detection, format-specific metadata
Vector .svg DOM parsing, embedded text, graphics metadata

Web & Data

Category Formats Features
Markup .html, .htm, .xhtml, .xml, .svg DOM parsing, metadata (Open Graph, Twitter Card), link extraction
Structured Data .json, .yaml, .yml, .toml, .csv, .tsv Schema detection, nested structures, validation
Text & Markdown .txt, .md, .markdown, .djot, .rst, .org, .rtf CommonMark, GFM, Djot, reStructuredText, Org Mode

Email & Archives

Category Formats Features
Email .eml, .msg Headers, body (HTML/plain), attachments, threading
Archives .zip, .tar, .tgz, .gz, .7z File listing, nested archives, metadata

Academic & Scientific

Category Formats Features
Citations .bib, .biblatex, .ris, .nbib, .enw, .csl Structured parsing: RIS (structured), PubMed/MEDLINE, EndNote XML (structured), BibTeX, CSL JSON
Scientific .tex, .latex, .typst, .jats, .ipynb, .docbook LaTeX, Jupyter notebooks, PubMed JATS
Documentation .opml, .pod, .mdoc, .troff Technical documentation formats

Complete Format Reference

Key Capabilities

  • Text Extraction - Extract all text content with position and formatting information

  • Metadata Extraction - Retrieve document properties, creation date, author, etc.

  • Table Extraction - Parse tables with structure and cell content preservation

  • Image Extraction - Extract embedded images and render page previews

  • OCR Support - Integrate multiple OCR backends for scanned documents

  • Async/Await - Non-blocking document processing with concurrent operations

  • Plugin System - Extensible post-processing for custom text transformation

  • Embeddings - Generate vector embeddings using ONNX Runtime models

  • Batch Processing - Efficiently process multiple documents in parallel

  • Memory Efficient - Stream large files without loading entirely into memory

  • Language Detection - Detect and support multiple languages in documents

  • Configuration - Fine-grained control over extraction behavior

Performance Characteristics

Format Speed Memory Notes
PDF (text) 10-100 MB/s ~50MB per doc Fastest extraction
Office docs 20-200 MB/s ~100MB per doc DOCX, XLSX, PPTX
Images (OCR) 1-5 MB/s Variable Depends on OCR backend
Archives 5-50 MB/s ~200MB per doc ZIP, TAR, etc.
Web formats 50-200 MB/s Streaming HTML, XML, JSON

OCR Support

Kreuzberg supports multiple OCR backends for extracting text from scanned documents and images:

  • Tesseract

  • Paddleocr

OCR Configuration Example

import dev.kreuzberg.Kreuzberg;
import dev.kreuzberg.ExtractionResult;
import dev.kreuzberg.KreuzbergException;
import dev.kreuzberg.config.ExtractionConfig;
import dev.kreuzberg.config.OcrConfig;
import java.io.IOException;

public class Main {
    public static void main(String[] args) {
        try {
            ExtractionConfig config = ExtractionConfig.builder()
                .ocr(OcrConfig.builder()
                    .backend("tesseract")
                    .language("eng")
                    .build())
                .build();

            ExtractionResult result = Kreuzberg.extractFile("scanned.pdf", config);
            System.out.println(result.getContent());
        } catch (IOException | KreuzbergException e) {
            System.err.println("Extraction failed: " + e.getMessage());
        }
    }
}

Async Support

This binding provides full async/await support for non-blocking document processing:

import dev.kreuzberg.Kreuzberg;
import dev.kreuzberg.ExtractionResult;
import java.nio.file.Path;
import java.util.concurrent.CompletableFuture;

public class Example {
    public static void main(String[] args) {
        CompletableFuture<ExtractionResult> future =
            Kreuzberg.extractFileAsync(Path.of("document.pdf"), null);

        future.thenAccept(result -> {
            System.out.println(result.getContent());
            System.out.println("Tables: " + result.getTables().size());
        }).join();
    }
}

Plugin System

Kreuzberg supports extensible post-processing plugins for custom text transformation and filtering.

For detailed plugin documentation, visit Plugin System Guide.

Embeddings Support

Generate vector embeddings for extracted text using the built-in ONNX Runtime support. Requires ONNX Runtime installation.

Embeddings Guide

Batch Processing

Process multiple documents efficiently:

import dev.kreuzberg.Kreuzberg;
import dev.kreuzberg.ExtractionResult;
import dev.kreuzberg.KreuzbergException;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;

try {
    List<String> files = Arrays.asList("doc1.pdf", "doc2.docx", "doc3.pptx");

    List<ExtractionResult> results = Kreuzberg.batchExtractFiles(files, null);

    for (int i = 0; i < results.size(); i++) {
        ExtractionResult result = results.get(i);
        System.out.println("File " + (i + 1) + ": " + result.getContent().length() + " characters");
    }
} catch (IOException | KreuzbergException e) {
    e.printStackTrace();
}

Configuration

For advanced configuration options including language detection, table extraction, OCR settings, and more:

Configuration Guide

Documentation

Contributing

Contributions are welcome! See Contributing Guide.

License

MIT License - see LICENSE file for details.

Support