Gradle Instead of Maven: Why We Made the Switch

Anyone working in the Java space can hardly avoid Maven. For years, it has been the standard build tool in the enterprise world -- proven, widely adopted, and supported by virtually every IDE. Nevertheless, we at encircle360 decided to migrate our projects to Gradle. In this article, we explain what motivated this step and what experiences we gathered along the way.

What Bothered Us About Maven

Maven works. That's beyond question. For simple projects with a standard structure, it reliably delivers results. But as soon as a project grows or the build logic becomes more complex, you hit Maven's limitations, which can only be worked around in cumbersome ways.

XML as a build language is the most obvious criticism. A pom.xml with several hundred lines is not uncommon, and adding custom build logic requires either writing a custom Maven plugin or using the maven-antrun-plugin -- neither of which is elegant. On top of that, multi-module projects in Maven quickly lead to a lot of redundant configuration, even with inherited parent POMs.

Build performance, however, was the decisive factor for us. In a project with multiple modules, a full Maven build regularly took over two minutes. Every small change to a single module triggered a complete rebuild of all dependent modules. That adds up over the course of a day.

Why Gradle

Gradle addresses exactly these weaknesses. It combines Maven's conventions with the flexibility of a real programming language -- Groovy -- as a build DSL. The result is a build system that works well for both simple and complex scenarios.

The Groovy DSL

Instead of XML, you write build scripts in Groovy. This may sound like an unnecessary hurdle at first, but in practice it's a huge win. A typical build.gradle for a Spring Boot project looks like this:

plugins {
    id 'java'
    id 'org.springframework.boot' version '2.0.0.RELEASE'
    id 'io.spring.dependency-management' version '1.0.4.RELEASE'
}

group = 'com.encircle360'
version = '1.0.0-SNAPSHOT'
sourceCompatibility = '1.8'

repositories {
    mavenCentral()
}

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-web'
    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
    runtimeOnly 'org.postgresql:postgresql'
    compileOnly 'org.projectlombok:lombok'
    annotationProcessor 'org.projectlombok:lombok'
    testImplementation 'org.springframework.boot:spring-boot-starter-test'
}

test {
    useJUnitPlatform()
}

// Custom build logic: simply define it as a task
task printVersion {
    doLast {
        println "Current version: ${version}"
    }
}

What immediately stands out: the file is compact, readable, and -- most importantly -- extensible. Custom build logic can be defined directly as a task without having to write a separate plugin. For Java developers, Groovy is quick to read, even without deep prior knowledge.

By the way, there is also a Kotlin DSL for Gradle that is currently under development. For production use, however, we would still recommend the proven Groovy DSL as of today.

Incremental Builds

The feature that makes the biggest difference in daily work is incremental builds. Gradle tracks which files serve as input and which outputs are produced for each task. If nothing has changed in the input since the last build, the task is skipped -- marked as UP-TO-DATE.

In practice, this means: if you change a single Java class, Gradle only compiles the affected module and skips everything else. For our multi-module projects, this reduced the average build time from over two minutes to under 20 seconds. That's not a marginal difference -- it noticeably changes the development workflow.

Build Cache

Since Gradle 4.x, the build cache has been available by default. It goes one step further than incremental builds: even if you switch between branches or run a clean, Gradle can reuse previously generated outputs from the cache, as long as the inputs are identical.

The build cache can be activated with a single line in gradle.properties:

org.gradle.caching=true

This is especially noticeable in CI/CD pipelines. When multiple developers build similar changes, build results can be shared team-wide -- via a remote build cache.

The Gradle Wrapper

One detail we learned to appreciate from the start is the Gradle Wrapper (gradlew). It ensures that every developer and every CI environment uses exactly the same Gradle version -- without manual installation. The gradlew script and its associated files are checked into the repository:

gradlew
gradlew.bat
gradle/
  wrapper/
    gradle-wrapper.jar
    gradle-wrapper.properties

A new developer clones the repository and can immediately run ./gradlew build. No installation guide, no version conflicts. Maven has since followed suit with the Maven Wrapper, but Gradle established this concept early on.

Spring Boot and Gradle

Since we at encircle360 work extensively with Spring Boot, integration was an important criterion. Spring Boot supports both build tools equally. The Spring Initializr (start.spring.io) offers both Maven and Gradle projects.

The spring-boot-gradle-plugin takes care of everything needed: it creates executable JARs, manages dependency versions through the io.spring.dependency-management plugin, and provides tasks like bootRun for quick startup during development.

The dependency-management plugin deserves special mention: it handles Spring Boot's BOM (Bill of Materials) management, so in most cases you don't need to specify explicit version numbers for Spring dependencies.

Where Maven Still Has Its Place

To be fair: Maven is not bad. For many projects, it remains a good choice. Maven's strengths lie in its simplicity and predictability. The "Convention over Configuration" principle works excellently as long as you stay within the conventions.

Maven also has a more mature plugin ecosystem and is more deeply rooted in the enterprise space. Anyone setting up a simple project without special build requirements will probably reach their goal faster with Maven. There is simply less to configure and fewer degrees of freedom that could be misused.

IDE support for Maven is also still excellent. IntelliJ IDEA and Eclipse understand Maven projects natively and flawlessly. Gradle integration has improved significantly in recent years but can still be occasionally finicky with synchronization.

Our Conclusion

For us, the switch to Gradle has paid off. Faster builds, the flexibility of the Groovy DSL, and features like the build cache make daily development more productive. Migrating existing projects was manageable -- the dependencies from pom.xml can be transferred almost one-to-one into build.gradle.

If you're facing this decision: give it a try. Gradle has a certain learning curve, especially coming from Maven. But the investment pays off, particularly for projects that go beyond a single module.