将Maven项目导入Eclipse 3.7（m2e 1.0），但是src / main / java未显示为源包

Question

I have a maven (3.0.4) multi-module build project which works on command line perfect.

mvn clean package

build successful.

I've tried to import that project into Eclipse

with m2e 1.0.

but after it's ready i can't see a package folder nor the icon for src-folders (like src/main/java etc).

But i would have expected to see something like the following:

Does someone has a hint what problem might be? Or ideas where to look for?

Update

After boiling this down it might be caused by using a Java 1.7. compiler which i have configurate like the following:

 <pluginManagement>
      <plugins>
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>2.5.1</version>
          <configuration>
            <source>${maven.compiler.source}</source>
            <target>${maven.compiler.target}</target>
            <executable>C:/Programme/Java/jdk1.7.0_05/bin/javac</executable>
            <fork>true</fork>
          </configuration>
        </plugin>
        ...

Someone with experience in this area?

Answer 1

It looks like your project doesn't have a Java nature. You can change this by right-clicking the project and going to

Properties -> Project Facets -> Convert to faceted form

From there you can add a Java facet, which should do the job. I often find with this sort of thing that it's easier to just edit Eclipse's .project and .classpath files manually (make sure to back them up before you do though!) instead. You'll probably want to check that your project's .project file includes something like this:

<?xml version="1.0" encoding="UTF-8"?>
<projectDescription>
    ...
    <buildSpec>
        <buildCommand>
            <name>org.eclipse.jdt.core.javabuilder</name>
            <arguments>
            </arguments>
        </buildCommand>
        <buildCommand>
            <name>org.eclipse.m2e.core.maven2Builder</name>
            <arguments>
            </arguments>
        </buildCommand>
    </buildSpec>
    <natures>
        <nature>org.eclipse.jdt.core.javanature</nature>
        <nature>org.eclipse.m2e.core.maven2Nature</nature>
    </natures>
</projectDescription>

Then make sure your .classpath looks something like this:

<?xml version="1.0" encoding="UTF-8"?>
<classpath>
    ...
    <classpathentry kind="src" output="target/classes" path="src/main/java"/>
    <classpathentry excluding="**" kind="src" path="src/main/resources"/>
    <classpathentry kind="src" output="target/test-classes" path="src/test/java"/>
    <classpathentry excluding="**" kind="src" output="target/test-classes" path="src/test/resources"/>
    <classpathentry kind="con" path="org.eclipse.m2e.MAVEN2_CLASSPATH_CONTAINER"/>
    <classpathentry kind="output" path="target/classes"/>
</classpath>

Once you've got all this stuff ready to go, update your project configuration like Michal said and refresh.

Answer 2

After long fiddling around i've found the problem which solves it for me:

I had a wrong lifecycle mapping for the maven-compiler-plugin (2.5.1) in my configuration which caused the problems. After removing it it works as expected no need to change the facets manually just import the project and it works.

Answer 3

In your eclipse, it might be pointing to JRE instead of JDK . Go to window->preference->java->Installed JRE . Add JDK here, and set it to default. You may need to restart eclipse.