# Build only subprojects in a dynamic multi-module project

**URL:** <https://discuss.gradle.org/t/build-only-subprojects-in-a-dynamic-multi-module-project/35512>\
**Category:** Help/Discuss\
**Created:** [April 2, 2020, 6:48am UTC](https://discuss.gradle.org/t/build-only-subprojects-in-a-dynamic-multi-module-project/35512 "2020-04-02T06:48:06Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![ParanoidUser](https://avatars.discourse-cdn.com/v4/letter/p/b38774/32.png) [@ParanoidUser](https://discuss.gradle.org/u/ParanoidUser)\
**Post date:** [April 2, 2020, 6:48am UTC](https://discuss.gradle.org/t/build-only-subprojects-in-a-dynamic-multi-module-project/35512/1 "2020-04-02T06:48:06Z")

</div>

Hello guys,

Sorry for the vague question, but I have a bad feeling that I’m doing something wrong.

There is a root project that contains a huge number of subprojects. Each subproject is a trivial Java sample with source code, tests, and documentation. At the same time, the **root project doesn’t have any source code by itself** only subfolders and build artifacts. Due to the high number of samples and their simplicity was decided not to create `build.gradle.kts` for each of them, instead include them dynamically by writing script in the parent `settings.gradle.kts`.

Here is how `build.gradle.kts` and `settings.gradle.kts` looks like:

### build.gradle.kts

```gradle
plugins {
    java.apply
}

subprojects {
    apply(plugin = "java")

    sourceSets {
        main {
            java {
                srcDir("main")
            }
        }
        test {
            java {
                srcDir("test")
            }
        }
    }

    repositories {
        mavenCentral()
    }

    dependencies {
        testImplementation("org.junit.jupiter", "junit-jupiter", "5.6.0")
    }

    tasks {
        test {
            useJUnitPlatform()
        }
    }
}

```

### settings.gradle.kts

```gradle
rootProject.name = "all-samples"

File(rootDir, "samples").walk().filter {
  it.isDirectory && File(it, "main").isDirectory
}.forEach {
  include(it.name)
  project(":${it.name}").projectDir = it
}

```

### Project structure:

```gradle
root
├── docs
├── gradle
├── samples
| ├── sampleA
| | ├── main
| | └── test
| ├── sampleB
| | ├── main
| | └── test
| └── [... many more]
...
├── build.gradle.kts
├── settings.gradle.kts
...

```

Finally the question 🙃: when I build the project as `./gradlew build` I see that **compileJava** task for the root project shows NO-SOURCE. Which basically means that Gradle executed Java plugin task to the root project didn’t find any sources and moved to its subprojects.

Q1. Is it possible to run a Java plugin task for subprojects only without listing all their names?  
Q2. Or somehow exclude Java-related tasks from execution against the root projects?

```gradle
> Task :compileJava NO-SOURCE
> Task :classes
> Task :compileTestJava NO-SOURCE
> Task :testClasses
> Task :test NO-SOURCE
> Task :sampleA:compileJava UP-TO-DATE
> Task :sampleA:classes
> Task :sampleB:compileJava UP-TO-DATE
> Task :sampleB:classes

```

P.S. I’ve tried `java.apply(false)` but got the error:

> Plugin ‘org.gradle.java’ is a core Gradle plugin, which is already on the classpath. Requesting it with the ‘apply false’ option is a no-op.

Any help is highly appreciated.

---

<div class="post-metadata">

**Author:** ![ParanoidUser](https://avatars.discourse-cdn.com/v4/letter/p/b38774/32.png) [@ParanoidUser](https://discuss.gradle.org/u/ParanoidUser)\
**Post date:** [April 5, 2020, 12:22am UTC](https://discuss.gradle.org/t/build-only-subprojects-in-a-dynamic-multi-module-project/35512/2 "2020-04-05T00:22:11Z")

</div>

Found the same issue described here: [https://github.com/gradle/kotlin-dsl-samples/issues/916](https://github.com/gradle/kotlin-dsl-samples/issues/916)  
But, the resolution is not quite clear to me. Do we have another way to accomplish this?

---

<div class="post-metadata">

**Author:** ![ParanoidUser](https://avatars.discourse-cdn.com/v4/letter/p/b38774/32.png) [@ParanoidUser](https://discuss.gradle.org/u/ParanoidUser)\
**Post date:** [April 15, 2020, 8:31pm UTC](https://discuss.gradle.org/t/build-only-subprojects-in-a-dynamic-multi-module-project/35512/3 "2020-04-15T20:31:42Z")

</div>

For the record: to exclude `compileJava` task from **rootProject** I use the `-x :compileJava`  
Example:

```gradle
./gradlew compileJava -x :compileJava

> Task :sampleA:compileJava UP-TO-DATE
> Task :sampleA:classes
> Task :sampleB:compileJava UP-TO-DATE
> Task :sampleB:classes

```

If you find a better way of doing this, please let me know.