CODEWITHSUNDEEP
javajava-9
MrSir
MrSir

Reputation: 596

Unable to find modules from module-info.java

I have 2 different projects in the same folder: com.jdojo.address and com.jdojo.person. The first has a simple pojo class Address and a module-info.java under default package: 

module com.jdojo.address {
    exports com.jdojo.address;
}

No errors here.

In the com.jdojo.person project I have a Person class that uses an Address attribute from the previous one. The module-info.java:

module com.jdojo.person {
    requires com.jdojo.address;
    exports com.jdojo.person;
}

I have an error in the requiresline:

module not found: com.jdojo.address

I have this issue both with NetBeans IDE Dev (Build 201708030001) and IntelliJ IDEA 2017.2.1.

├───com.jdojo.address
│   ├───.idea
│   │   └───inspectionProfiles
│   ├───nbproject
│   │   └───private
│   └───src
│       └───com
│           └───jdojo
│               └───address
├───com.jdojo.intro
│   ├───.idea
│   │   ├───inspectionProfiles
│   │   └───libraries
│   ├───build
│   │   ├───classes
│   │   │   └───com
│   │   │       └───jdojo
│   │   │           ├───address
│   │   │           ├───intro
│   │   │           └───person
│   │   ├───empty
│   │   └───generated-sources
│   │       └───ap-source-output
│   ├───dist
│   ├───nbproject
│   │   └───private
│   ├───src
│   │   └───com
│   │       └───jdojo
│   │           └───intro
│   └───test
├───com.jdojo.person
│   ├───.idea
│   │   └───inspectionProfiles
│   ├───nbproject
│   │   └───private
│   ├───src
│   │   └───com
│   │       └───jdojo
│   │           └───person
│   └───test
├───lib
├───mods
│   └───com.jdojo.intro
│       └───com
│           └───jdojo
│               └───intro
└───src
    └───com.jdojo.intro
        └───com
            └───jdojo
                └───intro

These are the module-info and java classes paths

C:\Java9Revealed\com.jdojo.address\src\module-info.java
C:\Java9Revealed\com.jdojo.address\src\com\jdojo\address\Address.java

C:\Java9Revealed\com.jdojo.person\src\module-info.java
C:\Java9Revealed\com.jdojo.person\src\com\jdojo\person\Person.java

Upvotes: 7

Views: 25924

Answers (2)

manuelvigarcia
manuelvigarcia

Reputation: 2104

Placement of the module-info.java

For me, the key was the placement of the module-info.java as well as the naming.

I am migrating a multi module maven project from Java 11 to Java 17. In Java 11, the project builds correctly until you add the module-info.java files. Then you may find different kinds of errors, ranging from "X module not visible" to "JavaDoc: no sources for module Y."

I generated automatically the module-info.java files with jdeps. This meant that the java modules were named after the maven project modules, which did not coincide with any java package name.

Renaming the module declaration to the actual java package, was a first step.

Then I tried to follow the placement of the module-info.java file according to the answers here but at the end, having one java module per maven module, was good enough to place the module-info.java inside the src/main/java directory, right where the com/company/application started for a module like com.company.application.api (instead of where the sources were, as I was told several places).

So, not src/main/java/com/company/application/api/module-info.java but src/main/java/module-info.java), for a module-info.java like this:

module com.company.application.api {
    exports com.company.application.api;
}

Upvotes: 0

Michael Easter
Michael Easter

Reputation: 24498

Per the Quick Start guide, it is convention to put the source-code in a folder named after the module. In this case, the folder structure should be:

com.jdojo.address/src/com.jdojo.address/module-info.java
com.jdojo.address/src/com.jdojo.address/com/jdojo/address/Address.java

com.jdojo.person/src/com.jdojo.person/module-info.java
com.jdojo.person/src/com.jdojo.person/com/jdojo/person/Person.java

It is illuminating to experiment using command-line tools, independent of any IDE. I have illustrated this case here.

Upvotes: 7

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