Develop Reference

ANT to Maven Migration. Maven alternative to build.xml

Background:
I am working on a open source tool called draw.io which is based on ANT build system and uses Java servelets to handle request. I am supposed to migrate it to spring boot with using same front end files. I put those files in static folder and tried to build the project. I figured that the front end js files were not getting build (i.e. were not getting converted to app.min.js, which is the main entry point for front end files), in the process and none of the js changes were getting reflected in the file.
I figured that this process was mentioned in build.xml as part of various steps which is ANT specific configuration. Now, I have to achieve the same in maven as the migration process.
How do we convert build.xml to maven or what is the maven alternative of achieving the tasks mentioned in the build.xml as part of build process?
This is the high level view of build.xml:->
I am also providing the link of build.xml here...
Please provide me with some direction.

Before migrating to maven, I hope you understand why you are moving to maven from ant.
You should try for finding alternative plugins for the relevant ant task. The below plugin might do what you are trying to achieve in ant
<plugin>
<groupId>com.github.blutorange</groupId>
<artifactId>closure-compiler-maven-plugin</artifactId>
<version>2.16.0</version>
<configuration>
<!-- Base configuration for all executions (bundles) -->
<baseSourceDir>${project.basedir}/src/main/resources</baseSourceDir>
<baseTargetDir>${project.build.directory}/generated-resources</baseTargetDir>
</configuration>
<executions>
<!-- Process all files in the "includes" directory individually-->
<execution>
<id>default-minify</id>
<configuration>
<encoding>UTF-8</encoding>
<sourceDir>includes</sourceDir>
<targetDir>includes</targetDir>
<includes>**/*.js</includes>
<skipMerge>true</skipMerge>
<closureLanguageOut>ECMASCRIPT5</closureLanguageOut>
</configuration>
<goals>
<goal>minify</goal>
</goals>
<phase>generate-resources</phase>
</execution>
</executions>
</plugin>
More details about the plugin : closure-compiler-maven-plugin
There are few cases during my ant to maven migration, I came across some custom tasks which I was not able to find appropriate plugins.
I used maven-antrun-plugin which keeps existing ant tasks in maven.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-antrun-plugin</artifactId>
<version>1.8</version>
<executions>
...
</executions>
</plugin>
More details about how to use the maven antrun plugin : See this
tutorial

For Maven, you need a pom.xml. There you need to define and configure the plugins you need. If you have a specific procedure written in Ant that you want to reuse, you can call it with the Maven Antrun Plugin.
Generally, Maven is very different from Ant. You don't write procedural code, but configure plugins running in a lifecycle.

Is there a Maven plugin that runs a non-fat jar?

Imagine a normal java maven project with a Main class that produces the artifact project-a.jar. This project has a dependency on project-b.jar.
Is there a Maven plugin that allows to run that jar by a command like that?
mvn run-plugin:run org.mygroup:project-a:3.1 <args>
The plugin would resolve the runtime dependencies (using META-INF/maven/(...)/pom.xml), install the project and its dependencies to the local maven repository (if not already there), construct the classpath and invoke
java -cp (...)/project-a-3.1.jar;(...)/project-b-2.1.jar org.mygroup.Main <args>
I know that the usual way is to build an executable (fat) jar that contains the dependencies, but that's not what I am asking for.
Actually, it is not even necesary to read the pom from the jar, because maven can download it from the repositories given the coordinates.
Why this question is different to the Maven Run Project question:
I do not want to start from having the project's source already checked out. So the usual use of the exec plugin is not applicable. The OP of the Maven Run Project question obviously assumed the presence of a source code project folder. Her purpose was testing and she accepted an answer that clearly needs a project. The wording of both questions is correct, too. There is a difference between the words "project" and "jar" and their actual meaning in their respective contexts is quite different.

You can use the appassembler-maven-plugin plugin, it creates a shell script that has the dependencies in the classpath for you. Heres an example config
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>appassembler-maven-plugin</artifactId>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>assemble</goal>
</goals>
</execution>
</executions>
<configuration>
<extraJvmArguments>-Xms256m -Xmx1536m</extraJvmArguments>
<programs>
<program>
<mainClass>com.package.MyMainClass</mainClass>
<name>TestFormattingUtils</name>
</program>
</programs>
</configuration>
</plugin>
You can find the output script in .../target/appassembler/bin You can manually inspect the script and you'll see that its doing the type of command you wanted where it adds the jars to classpath via the command line. ie java -jar (...)/project-a-3.1.jar -cp (...)/project-b-2.1.jar <args>

I'm not a fan of jars-in-jar either, but I do maintain various tools with lots of dependencies. So, at one point, I decided to write an executable AppBoot jar which puts all the jars from a lib-subdirectory in a class-loader and then calls the main-method of the desired (executable) jar. This question prompted me to investigate if the exec-maven-plugin could do something similar, and it can.
The exec-maven-plugin does not require a "Java project" directory, but a pom.xml in a directory is required. The pom.xml I used is shown below, note that it can be placed in any (empty) directory and the application can be started by opening a shell/prompt in that directory and executing mvn exec:exec. Use mvn -X exec:exec to review the classpath used by the exec-maven-plugin.
<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.descartes</groupId>
<artifactId>exec-embed-demo</artifactId>
<version>1.2.2-SNAPSHOT</version>
<packaging>pom</packaging>
<!-- Start the demo using Maven repository artifacts, execute with "mvn exec:exec" -->
<properties>
<demo.version>1.2.1.GH</demo.version>
<mainclass>com.descartes.basicjsp.embed.demo.Launch</mainclass>
<appname>${project.artifactId}</appname>
<homedir>${project.basedir}/</homedir>
</properties>
<dependencies>
<dependency>
<!-- exec-maven-plugin will get all required (runtime) jar-files from this dependency. -->
<groupId>com.descartes</groupId>
<artifactId>basic-jsp-embed-demo</artifactId>
<version>${demo.version}</version>
</dependency>
</dependencies>
<build>
<!-- The "outputDirectory" is added to the classpath by the exec-maven-plugin. -->
<!-- Add this pom's directory to the classpath instead of "./target/classes". -->
<!-- The directory should contain "logback.xml" to prevent a million lines of debug output from Tomcat. -->
<outputDirectory>${homedir}</outputDirectory>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>1.4.0</version>
<!-- mvn exec:exec configuration -->
<!-- Embedded Tomcat will not stop with "ctrl-c" -->
<!-- Use http://localhost:8080/shutdown instead -->
<configuration>
<executable>java</executable>
<arguments>
<argument>-Dapp.name=${appname}</argument>
<argument>-Dapp.home.dir=${homedir}</argument>
<argument>-Dapp.conf.dir=${homedir}</argument>
<argument>-cp</argument>
<classpath/>
<argument>${mainclass}</argument>
</arguments>
</configuration>
<!-- mvn exec:java configuration -->
<!-- "ctrl-c" stops Tomcat but embedded Tomcat fails to start properly, probably a classloader issue. -->
<!--
<configuration>
<mainClass>${mainclass}</mainClass>
<systemProperties>
<systemProperty>
<key>app.name</key>
<value>${appname}</value>
</systemProperty>
<systemProperty>
<key>app.home.dir</key>
<value>${homedir}/</value>
</systemProperty>
<systemProperty>
<key>app.conf.dir</key>
<value>${homedir}/</value>
</systemProperty>
</systemProperties>
</configuration>
-->
</plugin>
</plugins>
</build>
</project>
AppBoot is part of the basic-jsp-embed project that uses embedded Tomcat and that project can be found here (to install, download the latest release, unpack the zip-file and run "mvn install" in the root directory of the multi-module project).
On a side-note: managing a jar-set is tricky, use tools like jHades to verify you will not run into trouble with multiple versions of the same class in different jar-files.

You are looking for the maven exec plugin.
mvn exec:java -Dexec.mainClass="com.example.Main" [-Dexec.args="argument1"]
would run your program

Maven can not do what you want, simply because it has no way to resolve the dependencies of project A once it has been built into a final jar.
Maven does not magically download libraries from the Internet: what makes it work are the definition of repositories inside the pom.xml. Without pom.xml, like you seem to suggest, how would it know where to download libraries from? Maven is not a downloading tool, it is a project management tool and what you have is no longer a project but a final library.
Since you have control over project A, you should really rely on Maven conventions and either build a fat jar or an assembly (with maven-assembly-plugin).
By the way, the pom.xml file located under META-INF is not guaranteed to exist, and, in fact, it is not there if you look at Spring artifacts. Take a look at Maven Archiver documentation: the presence of this pom file is controlled by the addMavenDescriptor boolean attribute. Set this attribute to false and your main artifact will not have this pom file.

Can Maven Deploy a Module to JBoss?

We have a Maven project that we are using to deploy several wars to a JBoss server. We recently noticed that one of the jars that a couple of our wars depend on, uses Xerial. When Xerial starts it tries to load up a native driver, but only the first one successfully loads the native driver and the rest fail and fall back on a pure Java implementation because the native driver is already in a classloader. We would really like to gain the performance back by being able to load the native driver on all the wars.
It looks to me like the best way to do this would be add the jar we depend on to the JBoss server as a module, and then have the services depend on it.
My question is, is there a way we can get our Maven build to do this? Or are we going about this in the completely wrong way?

After a few days of looking, and talking to a couple of people who were much more familiar with JBoss-Maven interaction than me, it turns out the answer to my question is that it cant currently be done. There is no Maven plugin capable of deploying a Module to JBoss. This is largely in part to the fact that the modules are only loaded by JBoss when it starts, although if anyone is feeling particularly ambitious and wants to write their own Maven plugin, it could theoretically be worked around.
The answer #Robert Scholte left is a good one, and I learned from it, however it didn't actually answer my question.

First and most of all Apache Maven is a build management tool. It will "package" a project and will normally upload it to a repository so it can be used by other projects.
However, there are plugins available, which can deploy to JBoss:
http://mojo.codehaus.org/jboss-maven-plugin/ (maybe combined with http://mojo.codehaus.org/jboss-packaging-maven-plugin/ )
http://cargo.codehaus.org/
The first is JBoss specific, the latter a generic Java EE-container deploy plugin

I'd suggest to put your jar in the lib folder of the jboss server. This way, the jar is loaded in the shared classpath when the server starts. This will definitively serve the purpose.
Here is the jboss folder structured expleained.
http://docs.jboss.org/jbossas/guides/installguide/r1/en/html/dirs.html

I know this question has been marked as answered and the answer is that this currently is not possible, but I want to provide an alternative view. I am currently deploying Jboss modules to EAP 6.1 with Maven at my job. What we have done is use the maven-wagon plugin to scp the module to the tmp directory on the jboss server. I then use the maven-wagon plugin to issue a ssh command to the server to call the jboss-cli.sh script and tell it to perform a module installation. Here is a sample config:
<profile>
<id>uat</id>
<activation>
<activeByDefault>false</activeByDefault>
<property>
<name>switchEnv</name>
<value>uat</value>
</property>
</activation>
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>wagon-maven-plugin</artifactId>
<version>1.0-beta-5</version>
<executions>
<execution>
<id>upload-file-qa-server-one</id>
<phase>deploy</phase>
<goals>
<goal>upload-single</goal>
</goals>
<configuration>
<fromFile>${project.build.directory}/${project.build.finalName}.${project.packaging}</fromFile>
<url>scp://jboss#jboss-server-1/tmp/</url>
<toFile>${project.name}.${project.packaging}</toFile>
</configuration>
</execution>
<execution>
<id>upload-file-qa-server-two</id>
<phase>deploy</phase>
<goals>
<goal>upload-single</goal>
</goals>
<configuration>
<fromFile>${project.build.directory}/${project.build.finalName}.${project.packaging}</fromFile>
<url>scp://jboss#jboss-server-2/tmp/</url>
<toFile>${project.name}.${project.packaging}</toFile>
</configuration>
</execution>
<execution>
<id>install-module-qa-server-one</id>
<phase>deploy</phase>
<goals>
<goal>sshexec</goal>
</goals>
<configuration>
<serverId>jboss-server-1</serverId>
<url>scp://jboss#jboss-server-1/tmp</url>
<commands>
<command>/opt/jboss/bin/jboss-cli.sh -c --command="module add --name=${project.name} --resources=/tmp/${project.name}.${project.packaging} --dependencies=javax.api,javax.transaction.api"</command>
<command>sleep 5</command>
<command>rm -f /tmp/${project.build.finalName}.${project.packaging}</command>
</commands>
</configuration>
</execution>
<execution>
<id>install-module-qa-server-two</id>
<phase>deploy</phase>
<goals>
<goal>sshexec</goal>
</goals>
<configuration>
<serverId>jboss-server-2</serverId>
<url>scp://jboss#jboss-server-2/tmp</url>
<commands>
<command>/opt/jboss/bin/jboss-cli.sh -c --command="module add --name=${project.name} --resources=/tmp/${project.name}.${project.packaging} --dependencies=javax.api,javax.transaction.api"</command>
<command>sleep 5</command>
<command>rm -f /tmp/${project.build.finalName}.${project.packaging}</command>
</commands>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
</profile>
<profile>

It´s not possible beause you have to use an OSGI approach.
To use maven try to work with OSGI within EAP, but it depends what you looking for. OSGI is supported since JBoss EAP 6.1.
If you are trying to work with EAI try to work with JBoss Fuse instead of EAP.
Then you will work with maven repositories, nexus or similar, hot deploy and all OSGI bundles stuff.

Disable maven build number plugin

Currently we are working on the big maven project that has about 100 modules, some of them have submodules as well.
Some of modules use Maven Build Number plugin. The project is hosted under subversion.
Recently we started to use git locally in our development team.
After cloning subversion repo and trying to build the Project, we received following well known error:
The svn command failed.
Command output:
svn: ‘.’ is not a working copy
Unfortunately in our case it is not an option to create a new profile or just remove plugin definition from POM (this will follow to messing up hundreds of POM files).
I found the following article http://abstractionextraction.wordpress.com/2012/09/27/git-svn-vs-maven-build-number-plugin/ but honestly, it's not something that I would really like to do...
Is there any smart way to disable this plugin. Like command-line parameter?

I think you may skip failure on obtain revision without change project pom.xml - buildnumber-maven-plugin has option revisionOnScmFailure which you may use like:
mvn -Dmaven.buildNumber.revisionOnScmFailure=no-scm package
In that case value no-scm will be used if scm call was unsuccessful. Off course you may change it and provide any other string.

Per the mojo documentation, you could use the revisionOnScmFailure property.
However, it doesn't have a command line option. You'll have to modify those pom.xml files.
See "Defining Parameters Within a Mojo" in the Maven Java Plugin Development Guide

One approach would be to use a property in your pom to specify the execution phase of the build number plugin, as shown below.
<project>
..
<properties>
<buildnumber.plugin.phase>validate</buildnumber.plugin.phase>
..
</properties>
..
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>buildnumber-maven-plugin</artifactId>
<version>1.2</version>
<executions>
<execution>
<phase>${buildnumber.plugin.phase}</phase>
<goals>
<goal>create</goal>
</goals>
</execution>
</executions>
<configuration>
..
</configuration>
</plugin>
</plugins>
..
</project>
Then provide the property on the command line to disable the plugin, as shown in the following example.
mvn install -Dbuildnumber.plugin.phase=none

How to create Eclipse plugin with Spring support?

I have a problem when creating even simple Eclipse plugin with Spring support.
My main goal is to develop multi-module Eclipse plugin project using Apache Camel framework. That's why I'm trying to use Spring as IoC container(Camel has good Spring DSL) and Apache Maven as a build tool.
Now I have very simplified sub-goal: create simple Maven project for Eclipse plugin (like HelloWorld), which can create Spring's ApplicationContext by bundle-context.xml file, get some simple dependency from there, and, for instance, print it to console.
I started with spring-osgi-bundle-archetype archetype. I'm trying to use maven-bundle-plugin but without success. Currently, I have following configuration in pom.xml:
<plugin>
<groupId>org.apache.felix</groupId>
<artifactId>maven-bundle-plugin</artifactId>
<version>2.3.4</version>
<extensions>true</extensions>
<configuration>
<manifestLocation>META-INF</manifestLocation>
<ignoreMissingArtifacts>true</ignoreMissingArtifacts>
<instructions>
<Bundle-SymbolicName>${bundle.symbolicName}; singleton:=true</Bundle-SymbolicName>
<Bundle-Version>${pom.version}</Bundle-Version>
<!-- | assume public classes are in the top package, and private classes
are under ".internal" -->
<Export-Package>!${bundle.namespace}.internal.*,${bundle.namespace}.*;version="${pom.version}"</Export-Package>
<Private-Package>${bundle.namespace}.internal.*</Private-Package>
<Import-Package>.,*;resolution:=optional</Import-Package>
<Bundle-Activator>${bundle.namespace}.Activator</Bundle-Activator>
<Bundle-ActivationPolicy>lazy</Bundle-ActivationPolicy>
<Require-Bundle>org.eclipse.ui,org.eclipse.core.runtime</Require-Bundle>
<Bundle-RequiredExecutionEnvironment>JavaSE-1.6</Bundle-RequiredExecutionEnvironment>
<Embed-Dependency>*;scope=compile|runtime;inline=false</Embed-Dependency>
<Embed-Directory>target/dependency</Embed-Directory>
<Embed-StripGroup>true</Embed-StripGroup>
<Embed-Transitive>true</Embed-Transitive>
</instructions>
</configuration>
</plugin>
This configuration couse MANIFEST.MF generation with a lot of imported packages, all dependencies from pom.xml are embedded into target/dependency and declared in MANIFEST's Bundle-Classpath.
But plugin still doesn't work: there are errors like
NoClassDefFound: org.springframework.context.ApplicationContext
or
No available bundle exports package 'org.springframework.context'
(If I try to add this package to Import-Package forcingly).
But archive with this dependency (spring-context-3.0.5-RELEASE.jar) exists in target/dependency and in Bundle-Classpath.
I'm not very experienced in OSGi technology, so I even cannot understand whether this is a issue with Maven or with OSGi.
Does anyone has experience on creation Eclipse plugins with Spring support? Any advice and comments are welcome. Also it would be great to see some OpenSource Eclipse plugin with Spring support.

I would suggest you go with a manifest first build for your eclipse project, so you can use all the tools from eclipse for plugin stuff, see tycho and at the end of the page the examples.
EDIT: The links on the tycho page are broken, get the examples via github insteat, its the demo folder

Workaround was to add in pom.xml following code:
<plugin>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<id>copy-dependencies</id>
<phase>package</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
</execution>
</executions>
</plugin>
and call mvn package before Run/Debug plugin in Eclipse PDE.