Basic maven plugin project not working, Mojo plugin descriptors not generating
As mentioned in the previous answer, this was a bug and it is now fixed.
You just need to tell maven it should use a newer version of the maven-plugin-plugin
.
Here is what my pom file looks like:
<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">
<!-- ...other maven config... -->
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-plugin-plugin</artifactId>
<version>3.3</version>
</plugin>
</plugins>
</build>
</project>
Simply incrementing maven plugin version to 3.3 or 3.4 won't fix any issue (as some has stated).
You have to add a minimum of default-descriptor
execution with the correct phase.
So the minimum config of build information is as follows:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-plugin-plugin</artifactId>
<version>3.1</version>
<executions>
<execution>
<id>default-descriptor</id>
<phase>process-classes</phase>
</execution>
</executions>
</plugin>
</plugins>
</build>
irrespective of maven-plugin-plugin
version. (it can be 3.1, 3.2, 3.3. 3.4 (didn't test the others)).
will yield:
...
[INFO] --- maven-plugin-plugin:3.2:descriptor (default-descriptor) @ example-maven-plugin ---
[WARNING] Using platform encoding (UTF-8 actually) to read mojo metadata, i.e. build is platform dependent!
[INFO] Applying mojo extractor for language: java-annotations
[INFO] Mojo extractor for language: java-annotations found 1 mojo descriptors.
[INFO] Applying mojo extractor for language: java
[INFO] Mojo extractor for language: java found 0 mojo descriptors.
[INFO] Applying mojo extractor for language: bsh
[INFO] Mojo extractor for language: bsh found 0 mojo descriptors.
...
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
Another option if you don't want to have build tags in your pom, you can use javadocs on your Mojo. For instance:
/**
* @goal run123
*/
@Mojo(name = "run123")
public class MyMojo extends AbstractMojo {
}
will yield:
...
[INFO] --- maven-plugin-plugin:3.2:descriptor (default-descriptor) @ example-maven-plugin ---
[WARNING] Using platform encoding (UTF-8 actually) to read mojo metadata, i.e. build is platform dependent!
[INFO] Applying mojo extractor for language: java-annotations
[INFO] Mojo extractor for language: java-annotations found 0 mojo descriptors.
[INFO] Applying mojo extractor for language: java
[INFO] Mojo extractor for language: java found 1 mojo descriptors.
[INFO] Applying mojo extractor for language: bsh
[INFO] Mojo extractor for language: bsh found 0 mojo descriptors.
...
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
Please refer to this guide for more info http://maven.apache.org/plugin-tools/maven-plugin-plugin/examples/using-annotations.html
Maybe this is related to a unresolved issue in Maven: https://issues.apache.org/jira/browse/MNG-5346
For my plugin projects, i could workaround by adding an explicit execution of the maven-plugin-plugin:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-plugin-plugin</artifactId>
<version>3.2</version>
<configuration>
<!-- see http://jira.codehaus.org/browse/MNG-5346 -->
<skipErrorNoDescriptorsFound>true</skipErrorNoDescriptorsFound>
</configuration>
<executions>
<execution>
<id>mojo-descriptor</id>
<goals>
<goal>descriptor</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
But see the comments in the JIRA issue for more elaborate solutions!
after reading the Jira Issue that Gyro posted, i added the following lines to my pom and everything compiled nicely.
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-plugin-plugin</artifactId>
<version>3.2</version>
<configuration>
<goalPrefix>mysql-jdbc-compliance</goalPrefix>
</configuration>
<executions>
<execution>
<id>default-descriptor</id>
<goals>
<goal>descriptor</goal>
</goals>
<phase>process-classes</phase>
</execution>
<execution>
<id>help-descriptor</id>
<goals>
<goal>helpmojo</goal>
</goals>
<phase>process-classes</phase>
</execution>
</executions>
</plugin>
</plugins>
</build>