Java RTF conversion: Spire.Doc handles legacy formats, but open-source gaps remain
RTF documents from 1987 remain embedded in enterprise systems across APAC, creating headaches for web migration projects. Converting them to HTML or images means choosing between commercial libraries that work and open-source tools that mostly work.
Spire.Doc for Java handles the conversion competently. Load an RTF file with Document.loadFromFile(), save as HTML with FileFormat.Html, or export pages as PNG via saveToImages(). The API supports bi-directional RTF-to-DOCX conversion and outputs to 10+ formats including PDF and SVG.
What this means in practice: The library preserves formatting, embedded fonts, and images during conversion. For enterprises with complex RTF layouts, this matters. Apache POI and Tika handle basic RTF parsing but struggle with rendering fidelity.
The fine print: E-iceblue's GitHub repository hasn't seen commits since June 2022. The most recent tutorial dates to November 2025. Free-tier licensing limits will hit medium-sized operations. For shops processing thousands of legacy documents, the commercial license cost needs business case justification.
Open-source alternatives like Apache POI or PDFBox work for simple documents. They fail on complex layouts with embedded objects. Apache POI's "fontconfig head is null" error remains a known issue when rendering RTF with custom fonts. OpenPDF and PDFBox handle PDF generation but lack RTF-specific rendering engines.
Three things to watch: Performance at scale (Spire.Doc vs docx4j for batch operations), licensing costs for enterprise deployment, and whether Apache POI's RTF support improves. History suggests commercial libraries lead on format support while open-source tools catch up years later.
The real question for CTOs: Does your RTF migration project justify commercial licensing, or can you constrain scope to what open-source handles? Most choose the former. The latter requires accepting conversion quality trade-offs that business stakeholders rarely approve.