MavenError: Failed to execute goal on project: Could not resolve dependencies In Maven Multimodule project

Question

I am trying to create a maven multi-module project. the project is created successfully but when I am trying to use one module as a dependency of another module, it throws an exception. When I create a module using eclipse, I was selecting packaging as a jar, but when the module is created, the packaging tag was not mention in child pom.xml and I manually insert the packaging tag as a jar. following is my 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"> <modelVersion>4.0.0</modelVersion> <groupId>com.netsol</groupId> <artifactId>empirecl</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>pom</packaging> ------------------------- <modules>     <module>empirecl-web</module>     <module>empirecl-dao</module>     <module>empirecl-service</module>     <module>empirecl-api</module> </modules> 

Dao Child Module:

<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.netsol</groupId>     <artifactId>empirecl</artifactId>     <version>0.0.1-SNAPSHOT</version>     <relativePath>../pom.xml</relativePath> </parent> <artifactId>empirecl-dao</artifactId> <packaging>jar</packaging> <name>empirecl-dao</name> ------------------------ 

Service Child Module:

<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.netsol</groupId>     <artifactId>empirecl</artifactId>     <version>0.0.1-SNAPSHOT</version>     <relativePath>../pom.xml</relativePath> </parent> <artifactId>empirecl-service</artifactId> <packaging>jar</packaging> <name>empirecl-service</name>  <dependencies>     <dependency>         <groupId>com.netsol</groupId>         <artifactId>empirecl-dao</artifactId>         <version>0.0.1-SNAPSHOT</version>         <type>jar</type>     </dependency> ------------------------------------------ 

The Dao module maven clean and install successfully, but when i trying to use service module, it will generate an following exception:

[ERROR] Failed to execute goal on project empirecl-service: Could not resolve dependencies for project com.netsol:empirecl-service:jar:0.0.1-SNAPSHOT: Failed to collect dependencies at com.netsol:empirecl-dao:jar:0.0.1-SNAPSHOT: Failed to read artifact descriptor for com.netsol:empirecl-dao:jar:0.0.1-SNAPSHOT: Could not find artifact com.netsol:empirecl:pom:0.0.1-SNAPSHOT -> [Help 1] org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal on project empirecl-service: Could not resolve dependencies for project com.netsol:empirecl-service:jar:0.0.1-SNAPSHOT: Failed to collect dependencies at com.netsol:empirecl-dao:jar:0.0.1-SNAPSHOT 

I am trying the find to solution from web, but still the solution is not found. In eclipse when i open the Dependency Hierarchy of service module, it shown the DAO module as a folder not jar. below is the screen shot of Dependency Hierarchy of service module.

Answer 1

In case anybody comes back to this, I think the problem here was failing to install the parent pom first, which all these submodules depend on, so the Maven Reactor can't collect the necessary dependencies to build the submodule.

So from the root directory (here D:\luna_workspace\empire_club\empirecl) it probably just needs a:

mvn clean install 

(Aside: <relativePath>../pom.xml</relativePath> is not really necessary as it's the default value).

Answer 2

In my case I forgot it was packaging conflict jar vs pom. I forgot to write

<packaging>pom</packaging> 

In every child pom.xml file