A streaming HTML/CSS-to-PDF layout engine for print, with CSS Paged Media and JLREQ Japanese typesetting. Apache-2.0, Java 21, no browser required.
FolioJet is the layout engine behind Copper PDF, a server-side document converter that Japanese companies and publishers have used in production to print invoices, statements, tickets, catalogs and books. This fourth-generation engine was rewritten and open-sourced in 2026.
- Paged layout. CSS Paged Media: page boxes and margin boxes, page-break control, running headers and footers, footnotes, page floats and multi-column.
- Japanese typesetting to JLREQ. Vertical writing, kinsoku line-breaking driven by the JLREQ character-class tables, ruby (mono, group and jukugo), warichu, tate-chu-yoko, line-adjustment priority, and font fallback with kerning across CID-keyed and OpenType fonts.
- Streaming. Pages are laid out and emitted while the document is still arriving, so a long report generated from a slow cursor starts printing after the first page and runs in bounded memory.
- Several output formats from one layout: PDF, PNG/JPEG, a single SVG, and page-split SVG.
- Not a browser. JavaScript is not executed, by design.
<noscript>content is rendered. - Not a general-purpose renderer. The target is print. CSS that only affects interactive presentation is accepted and ignored rather than emulated.
- 1,693 unit tests, plus display-list golden comparisons.
- A randomized document sweep whose generator, oracle and automatic shrinker all
live in this repository (
RandomDocumentFuzzTest,FuzzOraclePredicateTest,FuzzShrinker). Every defect it has found is committed as a minimal fixed-seed regression underfiles/fuzz-repro/. - Hard invariants the suite exists to protect: never hang, never drop content, never emit an unintended blank page.
Java 21 and Gradle. FolioJet uses a Gradle composite build and expects four sibling repositories to be checked out next to it; see the Japanese section below for the exact layout, or run:
git clone https://github.com/zamasoftnet/cti.java.git
git clone https://github.com/zamasoftnet/html-balancer.git
git clone https://github.com/zamasoftnet/pdfg2d.git
git clone https://github.com/zamasoftnet/zstream.git
git clone https://github.com/zamasoftnet/foliojet.git
cd foliojet
./gradlew build以下は日本語の説明です。
HTML/CSS などのページング処理を担う公開ライブラリです。
Gradle ベースの単一プロジェクト構成です。ビルドは ./gradlew build を使います。
このリポジトリは Gradle の composite build で次の兄弟ディレクトリを参照します。
../../../zamasoftnet-public/cti.java- https://github.com/zamasoftnet/cti.java../../../zamasoftnet-public/html-balancer- https://github.com/zamasoftnet/html-balancer../../../zamasoftnet-public/pdfg2d- https://github.com/zamasoftnet/pdfg2d../../../zamasoftnet-public/zstream- https://github.com/zamasoftnet/zstream
例:
git clone https://github.com/zamasoftnet/cti.java.git
git clone https://github.com/zamasoftnet/html-balancer.git
git clone https://github.com/zamasoftnet/pdfg2d.git
git clone https://github.com/zamasoftnet/zstream.git
git clone https://github.com/zamasoftnet/foliojet.git
cd foliojet
./gradlew buildpdfg2d の Maven group は現時点では io.github.mimidesunya のため、build.gradle の io.github.mimidesunya:pdfg2d-* 依存はそのままにしています。ローカル開発時は settings.gradle の composite build により ../../../zamasoftnet-public/pdfg2d が使われます。
依存バージョンは build.gradle の dependencyVersions にまとめています。主な依存は次のとおりです。
- CTI Java (
cti-if,cti-driver-rest,cti-server-rest) 2.2.3 - pdfg2d (
pdfg2d-core,pdfg2d-font,pdfg2d-pdf,pdfg2d-svg) 1.2.0 - zstream (
zstream-io,zstream-resolver) 1.0.0-SNAPSHOT - Apache Batik (
batik-svggen,batik-script,batik-ext,batik-bridge,batik-gvt,batik-anim) 1.14 - Apache HttpComponents (
httpclient,httpcore,httpcore-nio,httpmime) - Apache Commons (
commons-collections,commons-io,commons-primitives) - XML/CSS (
xml-apis,xercesImpl,htmlunit-cssparser,html-balancer) - 画像・メタデータ (
metadata-extractor,imageio-jpeg) - その他 (
barcode4j,jeuclid-core,avalon-framework-impl,lib/Qrcode.jar)
Maven の pom.xml と Eclipse のプロジェクトメタデータには依存しません。
Apache License 2.0 （全文はリポジトリの LICENSE）