Gradle subproject not included in classpath

Question

We have a set up with 2 project, 1 main and 1 subproject, they are Java projects. They are all under the same directory.

Here is how the directory structure looks like :

Answer 1

Based on the Java Quckstart: Multi-project Java build:

1) your settings.gradle file needs to be in dev/, not dev/project_A and it should contain something like this:

include 'Project_A', 'Project_B'

2) Then your dev/Project_A/build.gradle file should contain

dependencies {
    compile project(':Project_B')
}

---

Edit:

I have created a toy example following the project layout you've described in your question. However, I haven't been able to reproduce the problem. Perhaps you'll be able to spot some difference that is causing your particular error:

Directory Tree

├── Project_A
│   ├── build.gradle
│   ├── settings.gradle
│   └── src
│       └── main
│           └── java
│               └── a
│                   └── A.java
└── Project_B
    ├── build.gradle
    └── src
        └── main
            └── java
                └── b
                    └── B.java

Project_A/build.gradle

apply plugin: 'java'
apply plugin: 'application'

mainClassName = 'a.A'

dependencies {
    compile project(':Project_B')
}

Project_A/settings.gradle

includeFlat 'Project_B'

A.java

package a;
import b.B;

public class A {
    public static void main(String[] args) {
        System.out.println("From A.main...");
        B.call();
    }
}

Project_B/build.gradle

apply plugin: 'java'

B.java

package b;

public class B {
    public static void call() {
        System.out.println("Calling B");
    }
}

When running Gradle from Project_A, the output is:

$ gradle clean build run
:clean UP-TO-DATE
:Project_B:clean UP-TO-DATE
:Project_B:compileJava
:Project_B:processResources UP-TO-DATE
:Project_B:classes
:Project_B:jar
:compileJava
:processResources UP-TO-DATE
:classes
:jar
:assemble
:compileTestJava UP-TO-DATE
:processTestResources UP-TO-DATE
:testClasses UP-TO-DATE
:test UP-TO-DATE
:check UP-TO-DATE
:build
:Project_B:assemble
:Project_B:compileTestJava UP-TO-DATE
:Project_B:processTestResources UP-TO-DATE
:Project_B:testClasses UP-TO-DATE
:Project_B:test UP-TO-DATE
:Project_B:check UP-TO-DATE
:Project_B:build
:run
From A.main...
Calling B

BUILD SUCCESSFUL

Answer 2

Ok, in case this is useful to someone, I finally got this working with actually removing (git rm) the .claspath file. It was in the .gitignore, but for some reason, it seems it had been comitted at some point and was playing around.

After doing this and re-importing the projects in Eclipse everything went back to normal.

Thanks to the ones who tried to help.