Develop Reference

Maven "process-classes" phase called for each reporting plugin (multiple executions)

I have a Maven artefact that includes data computed at compile-time
This is achieved by using the exec-maven-plugin to call the generating class.
This is correctly being executed when the artefact is built, but when reporting plugins are added, the execution is happening multiple times, slowing it down significantly.
Take the following 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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.me</groupId>
<artifactId>test</artifactId>
<version>0.0.1-SNAPSHOT</version>
<properties>
<main.class>test.Runner</main.class>
<maven.compiler.source>11</maven.compiler.source>
<maven.compiler.target>${maven.compiler.source}</maven.compiler.target>
</properties>
<reporting>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-report-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-report-plugin</artifactId>
</plugin>
</plugins>
</reporting>
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<executions>
<execution>
<phase>process-classes</phase>
<id>${main.class}</id>
<goals>
<goal>java</goal>
</goals>
<configuration>
<mainClass>${main.class}</mainClass>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-site-plugin</artifactId>
<version>3.9.1</version>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
When clean install site is run, the test.Runner is called three time - and each time a reporting plugin is added, it's run again.

Try changing the reports config to this:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-report-plugin</artifactId>
<version>${maven.surefire.plugin.version}</version>
<reportSets>
<reportSet>
<reports>
<report>report-only</report>
</reports>
</reportSet>
</reportSets>
</plugin>
This tells Maven which reports should be run. Without that reportSet config,
every reporting goal available in the plugin is rendered once
per the Maven Site plugin docs. This is important because as #khmarbaise notes, the report mojo
Invokes the execution of the lifecycle phase test prior to executing itself.

ANTLR4 CharStream class missing

I am using ANTLR4 to parse command lines for my Java Shell project.
When I run a JUnit test in VSCode, everything is fine. However, when I am building the Docker image and I try to run the shell in interactive mode, I get this error:
Error: Unable to initialize main class uk.ac.ucl.jsh.Jsh
Caused by: java.lang.NoClassDefFoundError: org/antlr/v4/runtime/CharStream
Is there any issue with my pom.xml file, or is the problem coming from somewhere else? This is my pom.xml file:
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>uk.ac.ucl.jsh</groupId>
<artifactId>jsh</artifactId>
<packaging>jar</packaging>
<version>1.0-SNAPSHOT</version>
<name>jsh</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.antlr</groupId>
<artifactId>antlr4-runtime</artifactId>
<version>4.7.2</version>
</dependency>
</dependencies>
<properties>
<maven.compiler.source>11</maven.compiler.source>
<maven.compiler.target>11</maven.compiler.target>
<argLine>-XX:MaxPermSize=512m</argLine>
</properties>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>3.0.0-M3</version>
</plugin>
<plugin>
<groupId>org.jacoco</groupId>
<artifactId>jacoco-maven-plugin</artifactId>
<version>0.8.4</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>uk.ac.ucl.jsh.Jsh</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<groupId>org.antlr</groupId>
<artifactId>antlr4-maven-plugin</artifactId>
<version>4.7.2</version>
<executions>
<execution>
<goals>
<goal>antlr4</goal>
</goals>
</execution>
</executions>
<configuration>
<visitor>true</visitor>
<listener>true</listener>
<outputDirectory>
${basedir}/src/main/java/
</outputDirectory>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
<reporting>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-pmd-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.jacoco</groupId>
<artifactId>jacoco-maven-plugin</artifactId>
<reportSets>
<reportSet>
<reports>
<!-- select non-aggregate reports -->
<report>report</report>
</reports>
</reportSet>
</reportSets>
</plugin>
</plugins>
</reporting>
</project>

This doesn't really look like an ANTLR problem. You'll need to look into how you're doing your build and how you're putting your Docker image together.
There are a couple of solutions to this.
Look into how to have Maven produce an Uber jar (i.e. a jar file that bundles up all of it's dependencies)
Ensure that your Docker image has the ANTLR runtime included and in your class path.
The first of those is probably the more "normal" solutions these days.

Could not find or load main class : Executable JAR from Maven

I am trying to create an executable JAR from Maven with maven-assembly-plugin. My Jars are getting created but without my source code. I have already mentioned goal as single in POM and creating jar with this command: "mvn clean package assembly:single". But I am still getting this error: "Error: Could not find or load main class com.som.bau.report.MainClass".
Please see below my 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>VFIE_SOM_BAU_Report</groupId>
<artifactId>SOM_BAU_Report</artifactId>
<version>0.0.1-SNAPSHOT</version>
<properties>
<jdk.version>1.7</jdk.version>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<version>2.9</version>
<configuration>
<downloadSources>true</downloadSources>
<downloadJavadocs>false</downloadJavadocs>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.2</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.4.1</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<mainClass>com.som.bau.report.MainClass</mainClass>
</manifest>
</archive>
</configuration>
<executions>
<execution>
<id>make-assembly</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
<dependencies>
<!-- Dependencies code goes here ---!>
</dependencies>
</project>

You should append packaging type to root element.
...
<modelVersion>4.0.0</modelVersion>
<groupId>VFIE_SOM_BAU_Report</groupId>
<artifactId>SOM_BAU_Report</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
...

I found the solution for it.
Need to add this tag under build tag.
<sourceDirectory>src</sourceDirectory>

Settting up line separator in Maven

We are working on a multi module Maven project where in one sub project we have some resources file (free marker template files). When we create EAR out of the project depending on Operating System Maven is updating line separator in template files.
If we run mvn install on windows it keeps line separator as and when we run it on linux it changes line separator to .
Template are created on Windows machine and have default separator as , we don't want Maven to changes to even if we build project on windows / linux. As code is always deployed on Windows machine and fails when encounters linux line separator.
Is there any way to tell Maven not to mess up with line separators?
Project POM looks like
<project>
<parent>
<groupId>com.xyz</groupId>
<artifactId>Foo</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<artifactId>FooBatch</artifactId>
<packaging>jar</packaging>
<properties>
<spring-version>4.1.4.RELEASE</spring-version>
</properties>
<dependencies>
<dependency>
<groupId>org.freemarker</groupId>
<artifactId>freemarker</artifactId>
<version>2.3.21</version>
</dependency>
// and more dependencies
</dependencies>
</project>
and here is the Parent POM
<project>
<modelVersion>4.0.0</modelVersion>
<groupId>com.xyz</groupId>
<artifactId>Foo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>pom</packaging>
<modules>
<module>FooBatch</module>
<module>FooEJB</module>
<module>FooEAR</module>
</modules>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<!-- http://maven.apache.org/plugins/maven-compiler-plugin/ -->
<source>1.6</source>
<target>1.6</target>
</configuration>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.18.1</version>
<configuration>
<!-- skips surefire tests without skipping failsafe tests. Property
value seems to magically default to false -->
<skipTests>${skipUnitTests}</skipTests>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-failsafe-plugin</artifactId>
<version>2.18.1</version>
<executions>
<execution>
<goals>
<goal>integration-test</goal>
<goal>verify</goal>
</goals>
<configuration>
<reportsDirectory>${project.build.directory}/surefire-reports</reportsDirectory>
<argLine>${jacoco.agent.arg}</argLine>
</configuration>
</execution>
</executions>
<configuration>
<!-- skips failsafe tests without skipping surefire tests. Property
value seems to magically default to false -->
<skipITs>${skipITTests}</skipITs>
</configuration>
</plugin>
<plugin>
<groupId>org.jacoco</groupId>
<artifactId>jacoco-maven-plugin</artifactId>
<version>0.7.2.201409121644</version>
<executions>
<execution>
<id>jacoco-initialize</id>
<goals>
<goal>prepare-agent</goal>
</goals>
</execution>
<execution>
<id>jacoco-site</id>
<phase>package</phase>
<goals>
<goal>report</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>

Try to add the following to your parent pom.
<project>
...
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>

Ensure test jars are named correctly

I'm setting up our system to do dual building for different versions of java artifacts based on the jdk used. There are 4 jars to build: artifact, artifact-tests, artifact-sources, and artifact-test-sources. Here is the output of the build
[INFO] Installing /Users/carlos/workspace/svn/Libraries/artifact-name/trunk/pom.xml to /Users/carlos/.m2/repository/package-path/artifact-name/1.0.8-SNAPSHOT/artifact-name-1.0.8-SNAPSHOT.pom
[INFO] Installing /Users/carlos/workspace/svn/Libraries/path/artifact-name-1.0.8-SNAPSHOT-java6.jar to /Users/carlos/.m2/repository/package-path/artifact-name/1.0.8-SNAPSHOT/artifact-name-1.0.8-SNAPSHOT-java6.jar
[INFO] Installing /Users/carlos/workspace/svn/Libraries/path/artifact-name-1.0.8-SNAPSHOT-sources.jar to /Users/carlos/.m2/repository/package-path/artifact-name/1.0.8-SNAPSHOT/artifact-name-1.0.8-SNAPSHOT-sources.jar
[INFO] Installing /Users/carlos/workspace/svn/Libraries/path/artifact-name-1.0.8-SNAPSHOT-test-sources.jar to /Users/carlos/.m2/repository/package-path/artifact-name/1.0.8-SNAPSHOT/artifact-name-1.0.8-SNAPSHOT-test-sources.jar
[INFO] Installing /Users/carlos/workspace/svn/Libraries/path/artifact-name-1.0.8-SNAPSHOT-tests.jar to /Users/carlos/.m2/repository/package-path/artifact-name/1.0.8-SNAPSHOT/artifact-name-1.0.8-SNAPSHOT-tests.jar
You can see the main artifact is built with java6 and has the appropriate classifier. I'm assuming the test classifier is overwriting the java6 classifier, but I'm unsure. Is there a way to get it to be named explicitly for both tests and the jdk? Something like -1.0.8-SNAPSHOT-tests-java6.jar. I'de like to refrain from doing manual changes to the final.name if possible and just use stock functionality like I did for the main artifact.
Here are the relevant parts of the pom.
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>${maven.jar.version}</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>${maven.compiler.version}</version>
<configuration>
<source>${jdk.version}</source>
<target>${jdk.version}</target>
<forceJavacCompilerUse>true</forceJavacCompilerUse>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-source-plugin</artifactId>
<version>${maven.source.version}</version>
</plugin>
</plugins>
</pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.9</version>
<executions>
<execution>
<id>analyze</id>
<goals>
<goal>analyze-only</goal>
</goals>
<configuration>
<failOnWarning>true</failOnWarning>
<ignoreNonCompile>true</ignoreNonCompile>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.4</version>
<!--<configuration>-->
<!--<skip>true</skip>-->
<!--</configuration>-->
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>${jdk.version}</source>
<target>${jdk.version}</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-source-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>jar</goal>
<goal>test-jar</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<classifier>${jdk.version.display}</classifier>
</configuration>
<executions>
<execution>
<goals>
<goal>test-jar</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
<profiles>
<profile>
<id>java6</id>
<activation>
<activeByDefault>false</activeByDefault>
<jdk>1.6</jdk>
</activation>
<properties>
<jdk.version>1.6</jdk.version>
<jdk.version.display>java6</jdk.version.display>
</properties>
</profile>
<profile>
<id>java7</id>
<activation>
<activeByDefault>false</activeByDefault>
<jdk>1.7</jdk>
</activation>
<properties>
<jdk.version>1.7</jdk.version>
<jdk.version.display>java7</jdk.version.display>
</properties>
</profile>
<profile>
<id>java8</id>
<activation>
<activeByDefault>false</activeByDefault>
<jdk>1.8</jdk>
</activation>
<properties>
<jdk.version>1.8</jdk.version>
<jdk.version.display>java8</jdk.version.display>
</properties>
</profile>
</profiles>

The -sources, -tests and -test-sources JARs are themselves using classifiers. So e.g. in the case of sources, you would need to override the maven-source-plugin's <classifier> configuration option (see also Maven deploy + source classifiers). I doubt that doing this is well tested across all the tool sets that consume -sources artifacts. For example, will Eclipse still download the sources for your java6 classifier artifact if you call the classifier java6-sources? And what about the tests, test-sources and (if you need it later) javadoc classifiers—will you complicate your POM further to generate all of those differently as well? Perhaps you could make it all work, but rather than trod down that path, it would be easier to simply use two different artifactIds, one for java6 and one for java7, and leave classifiers out of the equation.