Maven - Add a maven module as dependency to other maven module - spring

Question

I have 2 Spring boot maven projects(module A, Module B). And they both are added as modules to a parent project. Both Modules have some common dependencies and java classes(Domain objects), so I created third module Module C, and placed all the common java files and dependencies there.
I added the Module C to parent pom as one of the module. And added Module C as dependency to Module A and Module B. In Module A, B wherever the classes of Module C is referred there it was resolved and is pointing to Module C Classes (on ctrl+click).No error was shown in eclipse and maven dependencies are updated. But when I build the projects either from Parent pom or build Module A alone (after building the module c), I get cannot find symbol error in the places where module C classes were referenced.
Below are my pom.xml's
Parent pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.5.RELEASE</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<groupId>com.example.services</groupId>
<artifactId>cloud-services</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>pom</packaging>
<modules>
<module>ModuleC</module> <!-- Project where common dependencies and Common java classes are placed -->
<module>ModuleA</module>
<module>ModuleB</module>
</modules>
</project>
Module C Pom.xml - Common Project
<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.example.services</groupId>
<artifactId>cloud-services</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<artifactId>ModuleC</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>ModuleC</name>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Hoxton.SR3</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencyManagement>
</project>
Module A Pom.xml - Dependent Project on Module C
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.example.services</groupId>
<artifactId>cloud-services</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<artifactId>ModuleA</artifactId>
<dependencies>
<!-- Project where common dependencies and Common java classes are placed -->
<dependency>
<groupId>com.example.services</groupId>
<artifactId>ModuleC</artifactId>
<scope>compile</scope>
</dependency>
</dependencies>
</project>
Module B Pom.xml
Same as ModuleA.
Whats wrong with my configuration. Any help is much appreciated. Thanks.

Answer 1

If its a spring project the root folder of the jar would be BOOT-INF.
If you create a normal project jar it wouldn't be having BOOT-INF.
The way it works is if you have a Project A and it has dependency on x.jar
Say Project A needs com.x.y.ClassA.class from x.jar it will search in root folder of x.jar with this path x/y/ClassA.class.
In your case as it was a spring project the resolution didnt work and it was complaining about that.

Answer 2

I guess that the spring-boot-starter-parent is the culprit.
By using it as a parent POM to your parent POM, you are building all your modules with it. AFAIK, jars build with spring-boot-starter-parent cannot be used as dependencies because the classes are moved to a different directory inside the jar.
As I am not Spring expert, I cannot really offer you a good solution for this.