Develop Reference

Maven - Exclude Plugin from another Plugin

I've got a plugin that I need to use in my build. This plugin, however, has a build-time dependency on another plugin and that dependency does not work post-Java-8.
Specifically, the plugin that I want to use has this in its pom.xml file
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-antrun-plugin</artifactId>
<dependencies>
<dependency>
<groupId>com.sun</groupId>
<artifactId>tools</artifactId>
<version>${javaVersion}</version>
<scope>system</scope>
<systemPath>${tools.jar}</systemPath>
</dependency>
</dependencies>
<executions>
<execution>
<phase>test-compile</phase>
......
</execution>
</executions>
</plugin>
It's set to the test-compile phase, so it's only ever run when the plugin itself is being built, and not when it's being used.
The problem is that it's got the systemPath as part of the dependency, and this is set to something that is not resolvable using Java 9+. That in turn causes the build for the project using the plugin to fail with:
[ERROR] 'dependencies.dependency.systemPath' for com.sun:tools:jar must specify an absolute path but is ${tools.jar} #
So either I need to completely ignore the maven-antrun-plugin as part of my using this plugin, or I need to at least make the dependencies for it work.
Any thoughts?
Cheers

Could not find goal 'devmode' in plugin org.codehaus.mojo

I am a beginner in GWT and Maven. I created a new GWT Application project in Eclipse. Then, I converted that project into Maven Project by right-click on Project name => Configure => Convert to Maven Project and I saw that a pom file was generated for that project. Next, I run as project as Maven build but it was not compiled since a goal was not specified there. Actually, I don't understand what exactly have I to write under that goal section, therefore, I wrote package under that and then again I built maven and it compiled successfully.
After that, I tried to run this maven project in Command Prompt on the SuperDevMode using the 2nd step mentioned on Run the GWT Project under the Setting up a new project section. But while following these steps on Command Prompt, I got an error that devmode could not be found. Here is my Command prompt log:
C:\Users\TEST>cd eclipse-workspace/MyWebApp
C:\Users\TEST\eclipse-workspace\MyWebApp>mvn war:exploded
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building MavenApp 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-war-plugin:3.1.0:exploded (default-cli) # abcdef ---
[INFO] Exploding webapp
[INFO] Assembling webapp [abcdef] in [C:\Users\TEST\eclipse-workspace\MyWebApp\target\abcdef-0.0.1-SNAPSHOT]
[INFO] Processing war project
[INFO] Webapp assembled in [63 msecs]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.920 s
[INFO] Finished at: 2017-08-30T11:24:53+05:30
[INFO] Final Memory: 12M/107M
[INFO] ------------------------------------------------------------------------
C:\Users\TEST\eclipse-workspace\MyWebApp>mvn gwt:devmode
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.301 s
[INFO] Finished at: 2017-08-30T11:25:02+05:30
[INFO] Final Memory: 8M/107M
[INFO] ------------------------------------------------------------------------
[ERROR] Could not find goal 'devmode' in plugin org.codehaus.mojo:gwt-maven-plugin:2.8.1 among available goals clean, compile, compile-report, css, debug, eclipse, eclipseTest, generateAsync, help, i18n, mergewebxml, resources, run, run-codeserver, source-jar, test -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoNotFoundException
Here 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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>MyWebApp</groupId>
<artifactId>abcdef</artifactId>
<version>0.0.1-SNAPSHOT</version>
<build>
<sourceDirectory>src</sourceDirectory>
<testSourceDirectory>test</testSourceDirectory>
<resources>
<resource>
<directory>src</directory>
<excludes>
<exclude>**/*.java</exclude>
</excludes>
</resource>
</resources>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.6.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
<name>MavenApp</name>
<description>It is a maven app</description>
</project>
I searched a lot to resolve this error but found no solution for that issue. Please help me to fix this issue as I am very confused on how to fix it.
Edit: After further study, I used mvn gwt:run as an alternative to the command mvn gwt:devmode, but still I got another error on command prompt as given below:
[ERROR] Failed to execute goal org.codehaus.mojo:gwt-maven-plugin:2.8.1:run (default-cli) on project MyWebApp: The parameters 'runTarget' for goal org.codehaus.mojo:gwt-maven-plugin:2.8.1:run are missing or invalid

Without any more information than gwt:devmode, Maven will try to find an appropriate plugin, based on its default settings. It happens that a gwt-maven-plugin exists with org.codehaus.mojo as groupId, fitting in Maven built-in plugin resolution.
But this is not the plugin you're looking for.
You are probably trying to use this one, so just add this to your pom.xml, in the <plugins> section:
<plugin>
<groupId>net.ltgt.gwt.maven</groupId>
<artifactId>gwt-maven-plugin</artifactId>
<version>1.0-rc-8</version>
<extensions>true</extensions>
<configuration>
<moduleName>com.example.app.App</moduleName>
</configuration>
</plugin>
Adapting the moduleName if needed.

Well, I was able to solve this issue by copying some dependencies, plugin, and configuration from the pom.xml file (which is generated in the project created by the webAppCreator using maven) to the pom.xml file of my project created in the Eclipse. So, this is my pom.xml file created finally:
<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>MyPersonalProject</groupId>
<artifactId>MyPersonalProject</artifactId>
<version>0.0.1-SNAPSHOT</version>
<properties>
<!-- Setting maven.compiler.source to something different to 1.8
needs that you configure the sourceLevel in gwt-maven-plugin since
GWT compiler 2.8 requires 1.8 (see gwt-maven-plugin block below) -->
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
<!-- Don't let your Mac use a crazy non-standard encoding -->
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
</properties>
<dependencyManagement>
<dependencies>
<!-- ensure all GWT deps use the same version (unless overridden) -->
<dependency>
<groupId>com.google.gwt</groupId>
<artifactId>gwt</artifactId>
<version>2.8.1</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>com.google.gwt</groupId>
<artifactId>gwt-servlet</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>com.google.gwt</groupId>
<artifactId>gwt-user</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.google.gwt</groupId>
<artifactId>gwt-dev</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<outputDirectory>${project.build.directory}/${project.build.finalName}/WEB-INF/classes</outputDirectory>
<sourceDirectory>src</sourceDirectory>
<testSourceDirectory>test</testSourceDirectory>
<resources>
<resource>
<directory>src</directory>
<excludes>
<exclude>**/*.java</exclude>
</excludes>
</resource>
</resources>
<plugins>
<plugin>
<groupId>net.ltgt.gwt.maven</groupId>
<artifactId>gwt-maven-plugin</artifactId>
<version>1.0-rc-6</version>
<executions>
<execution>
<goals>
<goal>import-sources</goal>
<goal>compile</goal>
<goal>import-test-sources</goal>
<goal>test</goal>
</goals>
</execution>
</executions>
<configuration>
<moduleName>mypackage.MyPersonalproject</moduleName>
<failOnError>true</failOnError>
<!-- GWT compiler 2.8 requires 1.8, hence define sourceLevel here if you use
a different source language for java compilation -->
<sourceLevel>1.8</sourceLevel>
<!-- Compiler configuration -->
<compilerArgs>
<!-- Ask GWT to create the Story of Your Compile (SOYC) (gwt:compile) -->
<arg>-compileReport</arg>
<arg>-XcompilerMetrics</arg>
</compilerArgs>
<!-- DevMode configuration -->
<warDir>${project.build.directory}/${project.build.finalName}</warDir>
<classpathScope>compile+runtime</classpathScope>
<!-- URL(s) that should be opened by DevMode (gwt:devmode). -->
<startupUrls>
<startupUrl>MyPersonalProject.html</startupUrl>
</startupUrls>
</configuration>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.6.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
When I run this application using maven in the Command Prompt, it ran successfully except showing 2 or 3 warnings in the Command Prompt log. Also, I noticed that the SNAPSHOT generated in the version is different for the pom.xml created by Eclipse as compared to the one created by the maven project on command prompt.

When executing proguard-maven-plugin, "CreateProcess error=206, The filename or extension is too long" occurs

We are developing our own Eclipse plugin jars used by our Eclipse-based application. We are currently using proguard-maven-plugin version 2.0.8 to obfuscate them. However, when running mvn install on some plugins, we are currently encountering the following error:
[INFO] ---------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ---------------------------------------------------------------------
[INFO] Total time: 1:34.297s
[INFO] Finished at: Tue Apr 21 16:03:51 SGT 2015
[INFO] Final Memory: 88M/210M
[INFO] ---------------------------------------------------------------------
[ERROR] Failed to execute goal com.github.wvengen:proguard-maven-plugin:2.0.8:proguard (default) on project com.x.y: Execution default of goal com.github.wvengen:proguard-maven-plugin:2.0.8:proguard failed: java.io.IOException: Cannot run program "C:\Program Files (x86)\Java\jdk1.7.0_55\jre\bin\java.exe": CreateProcess error=206, The filename or extension is too long -> [Help 1]
Has anyone ever encountered this? If so, how did you solve the problem?
Note that I have actually seen this question and other related questions before deciding to ask but the answer by Brad Mace is not applicable to my case as the "CreateProcess error=206, The filename or extension is too long" is generated by Proguard and not by Javadoc. Initially, I think (correct me if I'm wrong) that either 1 of the 7 options given by espinchi or a variation of them might work but I'm not sure which one. Just to let you know my constraints in determining the solution:
I'm not sure if all of the classpaths in this particular plugin are
valid since this has been developed by someone else many, many years
ago so I don't think I can still contact the developer. This makes
me hesitant to reduce the classpaths for fear that it might actually
do more harm than good.
I cannot use the switch to "use IntelliJ" option since this problem occurred on the Windows command line when doing mvn install
and not in Eclipse IDE.
I think the other options are too tedious for me. I'm hoping there's a simpler solution.
For reference, below is the Proguard-related snippet from my pom file:
<build>
<plugins>
<plugin>
<groupId>com.github.wvengen</groupId>
<artifactId>proguard-maven-plugin</artifactId>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>proguard</goal>
</goals>
</execution>
</executions>
<configuration>
<maxMemory>1024m</maxMemory>
<proguardInclude>${basedir}/proguard.conf</proguardInclude>
<libs>
<lib>${java.home}/lib/rt.jar</lib>
</libs>
<exclusions>
<exclusion>
<groupId>com.company.package</groupId>
</exclusion>
</exclusions>
</configuration>
</plugin>
</plugins>
</build>

If you have a huge list of dependencies the list of -libraryjars the resulting command line to execute ProGaurd could become too long. On Windows the error message could look like CreateProcess error=206, The filename or extension is too long.
<putLibraryJarsInTempDir>true</putLibraryJarsInTempDir>
in plugin configuration makes the plugin copy all the library jars to a single temporary directory and pass that directory as the only -libraryjars argument to ProGuard. Build performance will be a bit worse, but the command line will be much shorter.
for detailed information about proguard maven plugin usage please refer their here

The reason to that is that generally maven repo is in user’s directory and that path adds on for every jar on the ‘classpath’ which makes it big enough for windows to handle.
The solution is that you need to move your maven repo to a shorter path – say C:. To do that you will need to edit maven settings.xml and add a tag as shown in the image link below. Once you do this, you can run maven clean install. This should solve the issue.
Maven Issue

Somehow, for our case, the ff. steps eliminated the error:
Compare the dependencies in the component's pom.xml and the dependencies identified by proguard-maven-plugin. In our case, we noticed that proguard-maven-plugin identified some dependencies that are not really need by the component. In fact, these dependencies are not even specified in the component's pom.xml.
After performing Step 1, modify the component's pom.xml such that it will exclude the unnecessary dependencies that Proguard has identified (i.e., use the exclusion parameter). Below is a sample snippet:
<build>
<plugins>
<plugin>
<groupId>com.github.wvengen</groupId>
<artifactId>proguard-maven-plugin</artifactId>
<version>2.0.10</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>proguard</goal>
</goals>
</execution>
</executions>
<configuration>
<maxMemory>1024m</maxMemory>
<proguardInclude>${basedir}/proguard.conf</proguardInclude>
<libs>
<lib>${java.home}/lib/rt.jar</lib>
<lib>${java.home}/lib/jce.jar</lib>
</libs>
<!-- For some reason, these components are included by the plugin even if they are not dependencies of SES components so we need to explicitly indicate to proguard-maven-plugin to exclude them. -->
<exclusions>
<exclusion>
<groupId>p2.eclipse-plugin</groupId>
<artifactId>org.apache.geronimo.specs.geronimo-jms_1.1_spec</artifactId>
</exclusion>
<!-- other exclusions here -->
</exclusions>
</configuration>
<dependencies>
<dependency>
<groupId>net.sf.proguard</groupId>
<artifactId>proguard-base</artifactId>
<version>5.2</version>
<scope>runtime</scope>
</dependency>
</dependencies>
</plugin>
</plugins>
</build>

Apparently this issue was solved in newer versions of the plug-in:
https://github.com/wvengen/proguard-maven-plugin/issues/113
Use this newly added config option, solved our case:
<configuration>
<generateTemporaryConfigurationFile>true</generateTemporaryConfigurationFile>
</configuration>

Maven sonar misconfiguration, maybe missing source directory?

When I do a mvn clean package locally everything works fine. When I do a mvn clean package on the jenkins server I get errors. I am running Jenkins 1.596, Maven 3.2.5, SonarQube 4.5.1, Maven plug-in 2.4 is defined in the Jenkins sonar settings.
This is the output from the Jenkins job.
[INFO] --- sonar-maven-plugin:2.4:sonar (default-cli) # myproject ---
[INFO] SonarQube version: 4.5.1
INFO: Work directory: /var/lib/jenkins/workspace/myporject/target/sonar
[INFO] [22:48:12.147] Base dir: /var/lib/jenkins/workspace/myproject
[INFO] [22:48:12.148] Working dir: /var/lib/jenkins/workspace/myproject/target/sonar
[INFO] [22:48:12.148] Source paths: src
[INFO] [22:48:12.148] Test paths: src/test/java
[INFO] [22:48:12.148] Binary dirs: target/classes
[INFO] [22:48:12.148] Source encoding: UTF-8, default locale: en_US
[INFO] [22:48:12.148] Index files
[ERROR] File [relative=src/test/java/com/blah/web/service.java, abs=/var/lib/jenkins/workspace/myproject/src/test/java/com/blah/web/service.java] can't be indexed twice. Please check that inclusion/exclusion patterns produce disjoint sets for main and test files
[ERROR] Failed to execute goal org.codehaus.mojo:sonar-maven-plugin:2.4:sonar (default-cli) on project myproject: File [relative=src/test/java/com/blah/web/service.java, abs=/var/lib/jenkins/workspace/myproject/src/test/java/com/blah/web/service.java] can't be indexed twice. Please check that inclusion/exclusion patterns produce disjoint sets for main and test files -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.codehaus.mojo:sonar-maven-plugin:2.4:sonar (default-cli) on project myproject: File [relative=src/test/java/com/blah/web/service.java, abs=/var/lib/jenkins/workspace/myproject/src/test/java/com/blah/web/service.java] can't be indexed twice. Please check that inclusion/exclusion patterns produce disjoint sets for main and test files
It appears that something is missing from my Sonar plug-in settings but I'm not sure what or where to define it.
Here are some snippets from 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>com.blah</groupId>
<artifactId>myproject</artifactId>
<version>99</version>
<packaging>war</packaging>
<name>myproject</name>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<routePath>${pom.project.build.directory}/routes</routePath>
<spring.release.version>3.2.4.RELEASE</spring.release.version>
<rabbitmq.version>3.1.4</rabbitmq.version>
<spring.amqp.version>1.2.0.RELEASE</spring.amqp.version>
</properties>
<build>
<finalName>myproject</finalName>
<sourceDirectory>src</sourceDirectory>
<scriptSourceDirectory>src/main/java</scriptSourceDirectory>
<testSourceDirectory>src/test/java</testSourceDirectory>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.2</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
<compilerId>groovy-eclipse-compiler</compilerId>
</configuration>
<dependencies>
<dependency>
<groupId>org.codehaus.groovy</groupId>
<artifactId>groovy-eclipse-compiler</artifactId>
<version>2.8.0-01</version>
</dependency>
<dependency>
<groupId>org.codehaus.groovy</groupId>
<artifactId>groovy-eclipse-batch</artifactId>
<version>2.1.8-01</version>
</dependency>
</dependencies>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<version>2.9</version>
<configuration>
<additionalProjectnatures>
<projectnature>org.eclipse.jdt.groovy.core.groovyNature</projectnature>
</additionalProjectnatures>
<classpathContainers>
<classpathContainer>org.eclipse.jdt.launching.JRE_CONTAINER</classpathContainer>
<classpathContainer>GROOVY_DSL_SUPPORT</classpathContainer>
</classpathContainers>
<sourceIncludes>
<sourceInclude>**/*.groovy</sourceInclude>
</sourceIncludes>
</configuration>
</plugin>
<plugin>
<artifactId>maven-failsafe-plugin</artifactId>
<version>2.18.1</version>
<dependencies>
<dependency>
<groupId>org.apache.maven.surefire</groupId>
<artifactId>surefire-junit47</artifactId>
<version>2.18.1</version>
</dependency>
</dependencies>
<executions>
<execution>
<goals>
<goal>integration-test</goal>
</goals>
<configuration>
<includes>
<include>**/integration/**/*.class</include>
</includes>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>

The problem seems to be that your source folder is a prefix of your test folder. In other words, if you say that your test folder is src/test/java/, your source folder should be src/main/java, not src since this causes the plugin to find the same class twice, which is what causes the error
Removing <sourceDirectory>src</sourceDirectory> should do the trick since it will use maven's default (src/main/java). While you're at it, remove also testSourceDirectory since you are setting it to the default value, so you don't need it. In general the pom should be as simple as possible since maven is all about convention over configuration

Maven site (Maven 3) generates empty site folder

I'm attempting to create a basic maven site using the maven site plugin. So I added this to my pom:
<reporting>
<plugins>
<!--JavaDoc setup-->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-javadoc-plugin</artifactId>
<version>2.7</version>
<configuration>
<defaultAuthor>Leon Blakey</defaultAuthor>
<defaultVersion>${project.version}</defaultVersion>
<links>
<link>http://download.oracle.com/javase/6/docs/api</link>
</links>
</configuration>
</plugin>
</plugins>
</reporting>
And ran mvn site --errors
[INFO] Error stacktraces are turned on.
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building pircbotx 1.3-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-site-plugin:2.0.1:site (default-site) # pircbotx ---
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.688s
[INFO] Finished at: Wed Jan 12 18:08:00 EST 2011
[INFO] Final Memory: 5M/13M
[INFO] ------------------------------------------------------------------------
W:\programming\pircbot-hg>
Hmm, odd that there's no output. So when I check target/site, its empty. The only folders are images/ , css/ , and WEB-INF/ , filled with some generic pictures. No javadoc and no site.
This is reproducible with mvn site:site and mvn org.apache.maven.plugins:maven-site-plugin:2.2:site (apparently maven only wants to use 2.0.1 by default)
Whats strange is that I can go back to maven 2.2.1 and successfully generate a site. But when I use 3.0.1-RC1 (happens to come with Netbeans), it fails.
What am I doing wrong that would make the site plugin fail in 3.0.1 but not 2.2.1?

Perhaps you can try using Maven Site Plugin 3.x. You can do that by adding the following in your pom.xml
<build>
...
<plugins>
...
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-site-plugin</artifactId>
<version>3.0-beta-3</version>
</plugin>
</plugins>
</build>

I was having the same problem. I found a blog post about the topic.
Quoting the blog (emphasis mine):
If you have been using the reporting section of the pom.xml file to generate code quality metrics, javadoc reports, and so forth, you may have a little work to do to migrate this feature into Maven 3. Indeed, the reporting and reportSets sections have been deprecated (it won't cause an error with Maven 3, it will just be ignored), and have been replaced by a reportPlugins section in the configuration block of the maven-site-plugin itself.
Ignoring the old <reporting> without any warning about it being deprecated seems a bit rude, but anyway...
So you are basically just moving your old reporting plugins into the configuration section of the new maven-site-plugin.
A section of the maven-plugin-site explains that they removed of all reporting logic from the core of Maven to "decouple the Maven core from Doxia and to allow arbitrary reporting systems to be developed." Makes sense.

Use of the Site Plugin ( http://maven.apache.org/plugins/maven-site-plugin/ ) with Maven 3 finally seems to be resolved. The (non-beta) version has been released, and the ability to use the version 2 style <reporting> structure in the pom.xml declaration has been added back.
Although it is (as usual) hard to navigate the substantial but unorganized and overlapping documentation about Maven 3 and the site plugin, one page - http://maven.apache.org/plugins/maven-site-plugin/maven-3.html - states that the old style is now recommended over the new "plugin to site plugin" style:
Note: In Maven 3, the new format does not support report plugins configuration inheritance: see MSITE-484. This format was technically necessary to remove reporting logic from Maven 3, but a new inheritance mechanism still needs to be added to Maven 3 to make it as flexible as the old format. So the new format is not ready for direct use for now.
The example page http://maven.apache.org/plugins/maven-site-plugin/examples/configuring-reports.html for configuring reports doesn't even mention the "new" formatting method.
Not sure if this is in a "best practice" form, but an example pom reporting section that works for me with a couple of extra reports is as follows; select your own plugins as desired.
...
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-site-plugin</artifactId>
<version>3.0</version>
</plugin>
</plugins>
</build>
<reporting>
<plugins>
<!-- Default Site Pages -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-project-info-reports-plugin</artifactId>
<version>2.4</version>
</plugin>
<!-- Java Documentation -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-javadoc-plugin</artifactId>
<version>2.8</version>
</plugin>
<!-- Source Code Cross-Reference -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jxr-plugin</artifactId>
<version>2.3</version>
</plugin>
...
</plugins>
</reporting>
As an aside, If you use the m2e plugin in Eclipse to edit your POMs, then you can use code completion in the version section of a plugin to give you a list of its current versions. Very handy.