[m2e-users] resources in Java folders

[Bruno Haible <bruno.haible@xxxxxxxxxx>]

Hi,

With m2e 1.4.0.20130601 I observe that the .classpath file generated by
"Maven > Update project" leads to inconsistent behaviour between Maven and
Eclipse.

Namely, when Eclipse builds the project, it copies all files except *.java 
and *.class
from src/main/java/ to target/classes/, whereas Maven does not. This leads 
to different
runtime behaviour (regarding whether resource files will be found or not), 
and the
developer wastes time tracking this down.


How to reproduce
================

1) In Eclipse, create a new plain "Java Project".
   In its Java Build Path, set the source directory to src/main/java 
instead of src.

2) To the project's .project file, add the following code snippets:
        <buildCommand>
            <name>org.eclipse.m2e.core.maven2Builder</name>
            <arguments>
            </arguments>
        </buildCommand>
and
        <nature>org.eclipse.m2e.core.maven2Nature</nature>
3) Add a 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.example</groupId>
        <artifactId>zzztest</artifactId>
        <version>1.0-SNAPSHOT</version>
        <packaging>jar</packaging>
        <name></name>

        <properties>
        </properties>

        <dependencies>
        </dependencies>

        <build>
        </build>

</project>

4) In Eclipse, on the project, do "Refresh" (F5).

5) In Eclipse, on the project, do "Maven > Update project".

6) Create some files in the directory src/main/java/:
  $ echo 'public class main {}' > main.java
  $ touch main.xml
  $ touch main.properties
  $ touch other.class
In Eclipse, on the project, do "Refresh" (F5).

7) Execute the compilation through maven:
  $ mvn clean package; ls -1 target/classes/
  main.class

8) Execute the compilation through Eclipse:
In Eclipse, select the project, then do "Project > Clean..." (with
"Build automatically" turned on).
  $ ls -1 target/classes/
  main.class
  main.properties
  main.xml
  META-INF

As you can see, Eclipse copies resource files to target/classes, while
Maven does not.


The problem
===========

The problem is the .classpath that "Maven > Update project" generated.
It contains the line
  <classpathentry kind="src" output="target/classes" path="src/main/java">

Instead, it should contain the line
  <classpathentry including="**/*.java" kind="src" path="src/main/java"/> 
With this line, the list of resources is consistent:
  $ ls -1 target/classes/
  main.class
  META-INF


Best regards,
----------------------------------------------------------------------------
Bruno Haible                            Email: <bruno.haible@xxxxxxxxxx>
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