[Java] Markdown 파싱

commonmark 라이브러리 사용

pom.xml

<dependency>
    <groupId>com.atlassian.commonmark</groupId>
    <artifactId>commonmark</artifactId>
    <version>0.16.1</version>
</dependency>

Basic

public class MarkdownToHtml {
    public static void main(String[] args) {
        Parser parser = Parser.builder().build();
        Node document = parser.parse("This is *Sparta*");

        HtmlRenderer renderer = HtmlRenderer.builder().build();
        String html = renderer.render(document);

        System.out.println(html); // <p>This is <em>Sparta</em></p>
    }
}

Customize HTML rendering

public class MarkdownToHtml {
    public static void main(String[] args) {
        HtmlRenderer renderer = HtmlRenderer
            .builder()
            .nodeRendererFactory(context -> new NodeRenderer() {
                @Override
                public Set<Class<? extends Node>> getNodeTypes() {
                    return Set.of(Heading.class, FencedCodeBlock.class);
                }

                @Override
                public void render(Node node) {
                    HtmlWriter writer = context.getWriter();

                    if (node instanceof Heading) {
                        // writer.line(); // newline
                        writer.tag("h3");
                        writer.text(((Text) node.getFirstChild()).getLiteral());
                        writer.tag("/h3");
                    }

                    if (node instanceof FencedCodeBlock) {
                        FencedCodeBlock codeBlock = (FencedCodeBlock) node;
                        writer.tag("pre", Map.of("class", codeBlock.getInfo()));
                        writer.tag("code");
                        writer.text(codeBlock.getLiteral());
                        writer.tag("/code");
                        writer.tag("/pre");
                    }
                }
            })
            .build();

        Parser parser = Parser.builder().build();
        Node document = parser.parse("### Hello\n```groovy\nprintln('Hello World')\n```");
        String html = renderer.render(document);

        System.out.println(html); // <h3>Hello</h3><pre class="groovy"><code>println('Hello World')
    }
}

참고

• https://github.com/commonmark/commonmark-java