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.

maven: execute without actually building anything

I have a project with finalised version in pom files , lets say 12.3.45 .
I have built the code for this version some time ago already, all the built jars are in the local maven repo.
Then at some point I have run mvn clean, so all the target folders are being removed.
And now I want to execute some code, as quickly as possible, using mvn exec:java. Preferably without building anything, because why not? all the jars at some point were already built, and I know there were no code changes after that. How can I force maven to execute the code as fast as possible , not recompile anything, and just reuse the jars from the local repo?
Thanks.

If your artifacts are in a local or remote repository you can use them as dependencies.
You can use exec-maven-plugin's options includeProjectDependencies or includePluginDependencies to use them in java execution
https://www.mojohaus.org/exec-maven-plugin/java-mojo.html#includePluginDependencies. includeProjectDependencies option is enabled (true) by default.
You can execute exec-maven-plugin without building anything with mvn exec:java command
Instructions:
To run exec-maven-plugin you would need a main class to run. I assume you have one in your project. If you don't - you need to make a separate project with a main class.
Create a blank maven project.
In the project add exec-maven-plugin configuration. Set the mainClass
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<goals>
<goal>java</goal>
</goals>
<configuration>
<mainClass>pack.App</mainClass>
</configuration>
</plugin>
</plugins>
</build>
Include you artifacts as dependencies to the project
<dependencies>
<dependency>
<groupId>my.group</groupId>
<artifactId>myartifact</artifactId>
<version>12.3.45</version>
</dependency>
</dependencies>
Run mvn exec:java to execute com.my.package.MyMainClass main class from my.group.myartifact artifact
Edits:
includeProjectDependencies option is enabled (true) by default

Maven failsafe does not run tests in submodule

I have a project with a parent directory containing the following in its pom.xml:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-failsafe-plugin</artifactId>
<version>2.20.1</version>
<executions>
<execution>
<goals>
<goal>integration-test</goal>
<goal>verify</goal>
</goals>
</execution>
</executions>
</plugin>
and
<modules>
<module>submodule</module>
</modules>
The submodule subdirectory again contains a pom.xml with a reference to its parent artifact. The subdirectory also contains a number of integration tests which run fine if I move the failsafe plugin into the submodule's pom.xml and then invoke mvn verify from the parent directory but this will not work with this current (preferred) setup (There are no errors, the tests are simply not executed).
I've tried adding the submodule artifact to dependenciesToScan in the failsafe plugin's configuration but that did not solve the problem. Do I need to add the submodule as a dependency in the parent pom.xml? Because that results in a "dependency is referencing itself" error while processing the pom.xml.
Help would be appreciated.
EDIT: I have figured it out, someone else working on the project had wrapped the build section in a profile section, I did not realise this at first because the whole file is rather large and unwieldly and I had overlooked the corresponding git commit. By undoing that change and following the instructions in the link posted by Gerald Broser I managed to solve my problem (I suppose just executing the respective profile would have also done it, but that change was uncalled for anyway).

See Maven Failsafe Plugin / Usage / Usage in multi-module projects:
When you are defining a shared definition of the Failsafe Plugin in a parent pom, it is considered best practice to define an execution id in order to allow child projects to override the configuration.

try to call
mvn clean verify -P <module>

How to run a multiple module project using Maven on NetBeans [duplicate]

I am new to maven. So I have a project with pom.xml file. So I ran that with maven and the build was successful. I have glassfish. Glassfish is already running separately. So now what is the next step to run the project with Glassfish? My IDE is eclipse.

You have to first tell Maven to build the WAR, check out this plugin for that: http://maven.apache.org/plugins/maven-war-plugin/.
Then you need to tell maven how to deploy to glassfish, you can either configure a Maven execution plugin to do this (see here: https://www.mojohaus.org/exec-maven-plugin/). Or you can look around for a custom plugin devoted to integrating maven with glassfish. This one looks promising, but I have not used it: http://maven-glassfish-plugin.java.net/.
Maven provides a lot of basic functionality out of the box, but most of the cooler stuff with build automation is done through plugins.
Update
Just updating to add a very simple Pom that will do a auto-deployment. Note: if you just run a "mvn clean install", with the packaging set to 'war', maven will build the .war file for you and place it in the target/ folder. You can take this and deploy it to glassfish manually if you just want to get started.
Below is part of a very simple pom that uses the Maven execution plugin to auto-deploy to glassfish as a function of the build:
<build>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>exec</goal>
</goals>
<phase>install</phase>
</execution>
</executions>
<configuration>
<executable>${path-to-asadmin-util}</executable>
<arguments>
<argument>deploy</argument>
<argument>--user=${username}]</argument>
<argument>--passwordfile=${password-file}</argument>
<argument>--host=localhost</argument>
<argument>--port=4848</argument>
<argument>target/${project.name}</argument>
</arguments>
</configuration>
</plugin>
</plugins>
</build>
This basically just calls the deploy command on the glassfish asadmin utility[1]. You need to fill in the following variables:
${path-to-asadmin-util} --> this is the path to your asadmin utility
(normally in the glassfish_home/bin)
${username} --> glassfish admin username
${password-file} --> password file for logging into glassfish
admin[2]
${project.name} --> name of your war
If you want to get more complicated I suggest taking a look at this thread: GlassFish v3 and glassfish-maven-plugin (Mac).
[1] - http://docs.oracle.com/cd/E18930_01/html/821-2433/deploy-1.html#SJSASEEREFMANdeploy-1
[2] - http://docs.oracle.com/cd/E18930_01/html/821-2435/ghgrp.html#ghytn

Additonnaly, you should have a glance at this StackOverflow thread, dealing with maven deployement in glassifsh : https://stackoverflow.com/a/1836691/1047365.
For further understanding of Maven, you should REALLY read this (free) book : http://www.sonatype.com/books/mvnref-book/reference/. This is THE reference for Maven.
We can explain you what Maven is doing, producing, etc ... but Sonatype made a great work and you'll probably learn more reading it than we could ever do !
Regards.

I found this tutorial useful: http://tshikatshikaaa.blogspot.com/2012/05/introduction-to-maven-concepts-crash.html

Maven – Always download sources and javadocs

Is there a way I can configure maven to always download sources and javadocs? Specifying -DdownloadSources=true -DdownloadJavadocs=true everytime (which usually goes along with running mvn compile twice because I forgot the first time) becomes rather tedious.

Open your settings.xml file ~/.m2/settings.xml (create it if it doesn't exist). Add a section with the properties added. Then make sure the activeProfiles includes the new profile.
<settings>
<!-- ... other settings here ... -->
<profiles>
<profile>
<id>downloadSources</id>
<properties>
<downloadSources>true</downloadSources>
<downloadJavadocs>true</downloadJavadocs>
</properties>
</profile>
</profiles>
<activeProfiles>
<activeProfile>downloadSources</activeProfile>
</activeProfiles>
</settings>
Edit: As mentioned by Jingguo Yao, this works with Eclipse IDE only - the same can also be configured in your IDE of choice. In Elcipse via Window -> Preferences -> Maven menu, though this probably has to done at every workspace level and for fresh Eclipse installations.
Alternatively configure the maven-dependency-plugin in your pom.xml in a separate profile and run it as required - keeping it in the main build will lead to build times (needlessly elongating (not to mention space) at places like your build nodes that don't need either sources or java docs. Preferable this should configured in some org or division parent pom.xml, otherwise it has be repeated everywhere in different places

In my case the "settings.xml" solution didn't work so I use this command in order to download all the sources:
mvn dependency:sources
You also can use it with other maven commands, for example:
mvn clean install dependency:sources -Dmaven.test.skip=true
To download all documentation, use the following command:
mvn dependency:resolve -Dclassifier=javadoc

Just consolidating and prepared the single command to address source and docs download...
mvn dependency:sources dependency:resolve -Dclassifier=javadoc

Answer for people from Google
In Eclipse you can manually download javadoc and sources.
To do that, right click on the project and use
Maven -> Download JavaDoc
Maven -> Download Sources

I am using Maven 3.3.3 and cannot get the default profile to work in a user or global settings.xml file.
As a workaround, you may also add an additional build plugin to your pom.xml file.
<properties>
<maven-dependency-plugin.version>2.10</maven-dependency-plugin.version>
</properties>
<build>
<plugins>
<!-- Download Java source JARs. -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>${maven-dependency-plugin.version}</version>
<executions>
<execution>
<goals>
<goal>sources</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>

On NetBeans :
open your project explorer->Dependencies->[file.jar] rightclick->Download Javadoc

As #xecaps12 said, the simplest/efficient approach is to change your Maven settings file (~/.m2/settings.xml) but if it is a default settings for you, you can also set it like that
<profile>
<id>downloadSources</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
<properties>
<downloadSources>true</downloadSources>
<downloadJavadocs>true</downloadJavadocs>
</properties>
</profile>

In Netbeans, you can instruct Maven to check javadoc on every project open :
Tools | Options | Java icon | Maven tab | Dependencies category | Check Javadoc drop down set to Every Project Open.
Close and reopen Netbeans and you will see Maven download javadocs in the status bar.

To follow up on the answer from kevinarpe this does both sources and Javadocs:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>3.1.1</version>
<executions>
<execution>
<goals>
<goal>sources</goal>
<goal>resolve</goal>
</goals>
</execution>
</executions>
<configuration>
<classifier>javadoc</classifier>
</configuration>
</plugin>
</plugins>
</build>

I think it can be done per plugin. See this chapter from the Maven book.
You might be able to configure the dependency plugin to download sources (even though I haven't tried it myself :-).

Simply modify file mvn (or mvn.cmd if in windows) and add whatever command line switches you need (as mentioned by other answers). If you don't want to modify the install files (which I'd recommend), create a mymvn (or mymvn.cmd) wrapper that invokes the regular mvn with the parameters.

Not sure, but you should be able to do something by setting a default active profile in your settings.xml
See
See http://maven.apache.org/guides/introduction/introduction-to-profiles.html

I had to use KeyStore to Download the Jars. If you have any Certificate related issues you can use this approach:
mvn clean install dependency:sources -Dmaven.test.skip=true -Djavax.net.ssl.trustStore="Path_To_Your_KeyStore"
If you want to know how to create KeyStores, this is a very good link:
Problems using Maven and SSL behind proxy

For the sources on dependency level ( pom.xml) you can add :
<classifier>sources</classifier>

For intellij users, inside the pom.xml file, right click anywhere and select Maven -> Download sources and Documentation.