Gradle Java

Key Points on Gradle Task Execution

1. Not All Tasks Run by Default

• Running ./gradlew tasks --all lists all available tasks but does not execute them.
• Gradle only runs tasks that are explicitly invoked or required by dependencies.

2. How Tasks Get Executed

✅ Explicit Invocation

./gradlew myCustomTask

This manually runs myCustomTask if it exists.

🔄 Task Dependencies

Tasks can be linked via dependsOn, causing them to execute automatically:

task myTask {
    dependsOn 'compileJava'
}

Now, running ./gradlew myTask also runs compileJava.

⚙️ Gradle Lifecycle Tasks

Certain high-level tasks trigger multiple others:

./gradlew build

This runs:

• compileJava
• processResources
• test
• jar
• assemble (if needed)

3. Why Some Tasks Never Run

• They are debugging or utility tasks (e.g., tasks, dependencies).
• They lack dependencies linking them to the main build flow.
• Gradle caching skips them if outputs didn’t change.

4. How to Check What Will Run

To see what tasks will execute without actually running them:

./gradlew <task-name> --dry-run

Example:

./gradlew build --dry-run

This simulates execution and prints the task sequence.

TL;DR

• Gradle doesn’t run all tasks by default—only invoked or required ones.
• Use dependsOn to link tasks and ensure execution order.
• Lifecycle tasks (build, test) trigger necessary dependencies.
• Check execution with --dry-run before running a full build.