Installation

mjml-java is a pure Java MJML-to-HTML renderer with zero external dependencies (for the core module). It requires Java 17 or later.

Modules

mjml-java is a multi-module project. Most users only need the core module:

Module	Artifact ID	Description
Core	mjml-java-core	MJML renderer, all 31 components, CSS inliner. Zero external dependencies.
Resolvers	mjml-java-resolvers	Additional IncludeResolver implementations: URL, caching, composite, map, prefix-routing. UrlIncludeResolver includes SSRF protections and explicit hostname allowlisting. Zero external dependencies (JDK java.net.http).
Spring	mjml-java-spring	Spring Boot 4.0+ auto-configuration, MjmlService, Thymeleaf integration.
BOM	mjml-java-bom	Bill of Materials for consistent version management.

Core Module

Maven

Add the following dependency to your pom.xml:

<dependency>
    <groupId>dev.jcputney</groupId>
    <artifactId>mjml-java-core</artifactId>
    <version>1.0.1</version>
</dependency>

Gradle

Add the following to your build.gradle:

implementation 'dev.jcputney:mjml-java-core:1.0.1'

Or for Kotlin DSL (build.gradle.kts):

implementation("dev.jcputney:mjml-java-core:1.0.1")

Using the BOM

To manage versions across multiple modules, import the BOM:

Maven

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>dev.jcputney</groupId>
            <artifactId>mjml-java-bom</artifactId>
            <version>1.0.1</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

<dependencies>
    <dependency>
        <groupId>dev.jcputney</groupId>
        <artifactId>mjml-java-core</artifactId>
    </dependency>
    <dependency>
        <groupId>dev.jcputney</groupId>
        <artifactId>mjml-java-resolvers</artifactId>
    </dependency>
</dependencies>

Gradle

dependencies {
    implementation platform('dev.jcputney:mjml-java-bom:1.0.1')
    implementation 'dev.jcputney:mjml-java-core'
    implementation 'dev.jcputney:mjml-java-resolvers'
}

JPMS (Java Module System)

The core module is fully JPMS-ready. Add the following to your module-info.java:

module your.module {
    requires dev.jcputney.mjml;
}

The dev.jcputney.mjml module requires java.xml and java.logging, which are included in all standard JDK distributions.

Exported Packages

The module exports the following packages:

Package	Description
dev.jcputney.mjml	Public API: MjmlRenderer, MjmlConfiguration, MjmlRenderResult
dev.jcputney.mjml.css	CSS inlining engine
dev.jcputney.mjml.component	Component base classes and registry
dev.jcputney.mjml.context	Rendering context and attribute resolution
dev.jcputney.mjml.parser	MJML parser and preprocessor

Requirements

• Java 17 or later
• Core and Resolvers modules: zero external dependencies (JDK standard library only)
• Spring module: Spring Boot 4.0+, optional Thymeleaf 3.1+