Develop Reference

Maven not adding all dependencies to jar

I've a simple program build in IntelliJ and using maven that uses the dependency io.netty. I've added to my POM file:
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
<version>4.1.0.Beta1</version>
</dependency>
In order to compile and get a jar file I usually do:
Clean
Compile
Package
However I noticed that the dependency is not added to the jar, neither existing in the target folder (Or in any of it's sub folders) or added to the resources folder like usually happens.
In order to have the io.netty library to be added to the jar I have tried:
Setting the scope to provided and to compile.
Re-importing the pom file.
Deleting io.netty folder in the .m2/repository/ folder.
I have several other libraries linked including:
mysql-connector-java
slf4j-simple
trove4j
Thanks for reading.

For some odd reason I had changed my maven configuration a while ago. While I had not added any new libraries, the old ones still had their classes laying around therefor still being added to the jar.
I solved this issue by changing the build in my pom to:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.4</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<mainClass>com.domain.Program</mainClass>
</manifest>
</archive>
</configuration>
<executions>
<execution>
<id>make-assembly</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
Used as reference: http://mkyong.com/maven/create-a-fat-jar-file-maven-assembly-plugin/

Maven doesn't package all dependencies into a jar by default. You can use the assembly plugin to build a "jar with dependencies, as seen here:
How can I create an executable JAR with dependencies using Maven?

How to configure Maven build for Java project with external dependencies?

I'm trying to create automated solution for building with maven. My vision is to have a Maven build, which creates JAR file from my project and then just copies all the dependencies as JARs to some sub-directory in "target" folder.
I do not want to use Shade or Assembly (so I do not want to extract the content of other JARs and include it in one "super-JAR", because the project is more complicated and it breaks when I'm including all the JARs in one file).
How can I do such build POM?

I don't see here any problem. Just create maven pom.xml with <packaging>jar</packaging>
By default it should not pack into your jar all dependent libraries.
<plugin>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<phase>install</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}/lib</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>

Related with your latest comment, use this plugin to add the main class in the manifest:
<plugin>
<!-- Build an executable JAR -->
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>lib/</classpathPrefix>
<mainClass>com.test.YourMainClass</mainClass>
</manifest>
</archive>
</configuration>
</plugin>

You can use the maven-assembly-plugin to create a .zip file from a selection of other files in your directory. I have used this method to create distribution zip files for a project. There are several examples available in the maven-assembly-plugin documentation.

Maven deploy jar with dependencies to repo

I can deploy a jar by using the following in my pom.xml and running mvn deploy:
<distributionManagement>
<repository>
<id>releases</id>
<url>http://${host}:8081/nexus/content/repositories/releases</url>
</repository>
<snapshotRepository>
<id>snapshots</id>
<name>Internal Snapshots</name>
<url>http://${host}:8081/nexus/content/repositories/snapshots</url>
</snapshotRepository>
</distributionManagement>
And I can build an executable jar-with-dependencies using the following:
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<executions>
<execution>
<id>create-executable-jar</id>
<phase>deploy</phase>
<goals>
<goal>single</goal>
</goals>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<mainClass>my.company.app.Main</mainClass>
</manifest>
</archive>
</configuration>
</execution>
</executions>
</plugin>
Problem is I don't know how to stitch these together to deploy the executable jar to my Maven repo. I don't really know if this is accomplished by a new plugin or by adding a goal or other step to the existing assembly plugin.

If you bind the assembly to the packaging phase, it will install in your repository both the "regular" jar and the with-dependencies jar when you do a build:
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>my.company.app.Main</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>make-assembly</id> <!-- this is used for inheritance merges -->
<phase>package</phase> <!-- bind to the packaging phase -->
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
Then simply run mvn clean install deploy to upload both jars to your repository.

In order to build a (so-called) Über JAR and deploy it using maven, you could also use the shade plugin. The following code is taken from their website but I've made one or two projects using this feature.
<project>
...
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>2.0</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<shadedArtifactAttached>true</shadedArtifactAttached>
<shadedClassifierName>jackofall</shadedClassifierName> <!-- Any name that makes sense -->
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
...
</project>
In this configuration you get the Über JAR as one deployment besides the normal JAR. The user of your JAR can then decide to pull the all-in-one package or the JAR with dependencies based on the classifier.
I'll usually use the shade plugin to build Über JARs (or modify the JAR in a way) and use the assembly plugin to build things like installation packages (containing the JAR and possibly other things). I am unsure what the intended goals of the single plugins are however.

The following worked. I'm going to leave this question open a bit because I'm not positive this is best practice, but working is something.
Problems I notice are that I made up the ID name and I don't know if this is usual practice and that I have to hard code the jar name; it isn't inferred from anything else.
<plugin>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.7</version>
<executions>
<execution>
<id>deploy-executable</id>
<goals>
<goal>deploy-file</goal>
</goals>
<configuration>
<file>target/Monitoring-Client-1.0-SNAPSHOT-jar-with-dependencies.jar</file>
</configuration>
</execution>
</executions>
</plugin>

Essentially my difficulty doing this revealed the fact that my pom.xml was way off the rails already. Everything would have snapped into place on its own. I was formerly doing:
Save all the dependencies into a lib folder
Build a jar with a classpath slurping up that lib folder
Use the assembly plugin to make another deployable jar
I think there were several reasons this sort of made sense along the way, especially when my libraries were not well-factored from my applications.
However by deleting 1 and 2 all that is needed is the distributionManagement section and the deploy phase works automagically. So all in all this is an amazing case of literally adding functionality by deleting large swathes of code.

First you shouldn't do the creation of the ueber jar in the deploy phase it's better to do this in the package phase. Furthermore the created jar file is usually automatically attached to your artifact and will be transfered to the remote repository (in your case Nexus). You can check this if you simply try to do a mvn install and take a look at the output if the created jar is installed into the local repository.
To deploy the results into nexus you need to call mvn deploy.

how to use class file from another war

We have two different web application and we want to extend few controllers of one war into another war.
We are using maven to build the project.
to include war we have given its dependency as
<dependency>
<groupId>com.abc.exchange</groupId>
<artifactId>employer</artifactId>
<version>2.3.M2-SNAPSHOT</version>
<type>war</type>
<scope>compile</scope>
</dependency>
It is unable to build giving class not found exception.
Can any body help me out how to achieve this?
I am getting error maven build failed :
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (default-compile) on project agent-war: Compilation failure: Compilation failure:
[ERROR] \projects\trunk_new\agent\src\main\java\com\platform\agent\web\AgentEmployeeController.java:[22,41] cannot find symbol
[ERROR] symbol : class EmployeeController
[ERROR] location: package com..platform.employer.web

You can define the war plugin to produce a separate jar file which is available via a classifier based on the configuration:
<configuration>
..
<attachClasses>true</attachClasses>
<archiveClasses>true</archiveClasses>
</configuration>
After that you can use this as a separate dependency in other projects. But the best to make a separate jar module out of it.

What you are doing is using a WAR file overlay. Maven does support this. However...
The WAR plugin executes in the package phase. Any plugin, such as the Java compiler (which runs in the compile phase), that executes before this phase will not see any files that the WAR plugin has extracted. (here is the reference list of all Maven phases if that helps)
If you have the ability to refactor your project structure, the best way is to create a normal JAR project with your controllers and have both WARs pull this JAR in as a dependency.
If there is some reason why you can't do this, you will need to do something like:
Configure the WAR plugin to run in a phase earlier than compile, such as generate-resources and makes sure it extracts the overlay class files to ${project.build.outputDirectory}.
You could also use the Maven Dependency Plugin's unpack goal to extract classes from the dependency WAR to ${project.build.outputDirectory}.
But I do recommend if at all possible to refactor your controllers into a separate JAR, it is much easier and more maintainable.

put the controllers into a new jar project and make dependencies from your webprojects to this controllers.

Add the following plugins to your share maven war module (for creating war and jar artifact at the same time):
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.4</version>
<executions>
<execution>
<id>make-a-jar</id>
<phase>compile</phase>
<goals>
<goal>jar</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-install-plugin</artifactId>
<version>2.4</version>
<executions>
<execution>
<phase>install</phase>
<goals>
<goal>install-file</goal>
</goals>
<configuration>
<packaging>jar</packaging>
<artifactId>${project.artifactId}</artifactId>
<groupId>${project.groupId}</groupId>
<version>${project.version}</version>
<file>
${project.build.directory}/${project.artifactId}-${project.version}.jar
</file>
</configuration>
</execution>
</executions>
</plugin>
then add dependency to your dependent maven war module.

Java EE visability standards state that classes from one war shouldn't be available to classes in another war, when they're packaged as an EAR. Most containers will enforce this strictly.
You should put the code you wish to share into a JAR and include that as a dependency in the war you want to use.

In the war project pom.xml include
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.1.1</version>
<configuration>
<attachClasses>true</attachClasses>
</configuration>
</plugin>
This will create your-project-0.0.1-SNAPSHOT-clases.jar in the target folder along with the war.
In the dependent project pom.xml include
<dependency>
<groupId>com.yourproject</groupId>
<artifactId>you-project</artifactId>
<version>0.0.1-SNAPSHOT</version>
<classifier>classes</classifier>
</dependency>
This worked for me. Hope it helps.
Edit: If we want only some class files into the jar then add this to pom.xml
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.4</version>
<executions>
<execution>
<id>make-a-jar</id>
<phase>compile</phase>
<goals>
<goal>jar</goal>
</goals>
<configuration>
<classifier>classifier_name</classifier>
<includes>
<include>com/../..</include>
</includes>
</configuration>
</execution>
</executions>
</plugin>
In the dependent project pom.xml include
<dependency>
<groupId>com.yourproject</groupId>
<artifactId>you-project</artifactId>
<version>0.0.1-SNAPSHOT</version>
<classifier>classifier_name</classifier>
</dependency>
note: the classifier name must be same in both pom.xml files

log4j configuration file in a multi-module Maven project

I am working on a multi-module Maven project, whose structure is like this:
war-module
jar-module
The war-module depends on the jar-module, and will add the jar artifact into the webapp's lib directory after packaging.
And both the war-module and jar-module use Apache log4j for logging, and share the same log4j configuration file (log4j.xml), which locates in jar-module project at present. And this log4j.xml will be packaged into jar-module.jar file, however, I would like to make it into WEB-INF/classes directory in the war package rather than in the jar file so that users will be easy to find this configuration file and modify it if necessary (it is very hard for them to find it if this file is in the WEB-INF/lib/jar-module.jar because there are many other jars under that directory).
My question is: what is the Maven way to solve this problem?
Update:
My real project is a bit more complex, and there is a ear-module which depends on the jar-module too (aka. the jar-module can be used independently in several different projects, and I cannot just put the file into war-module/src/main/resources directory to fix this problem). And I don't want to duplicate some configuration files such as log4j.xml (and other configuration files such as myapp.properties) across the several projects.

I found the answer via some more searching on the web.
Generally, there are three ways to share resources in a multi module Maven project:
Cut and paste them.
Use Assembly and Dependency plugins
Use the maven-remote-resources-plugin
Here's a blog post from Sonatype, the company behind Maven, on sharing resources across projects in Maven, and it is the exact answer I need:
http://www.sonatype.com/people/2008/04/how-to-share-resources-across-projects-in-maven/

In the jar module, exclude the file from the jar:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.3.1</version>
<configuration>
<excludes>
<exclude>log4j.xml</exclude>
</excludes>
</configuration>
</plugin>
Use the buildhelper plugin to attach the log4j.xml to the build as a separate artifact
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>build-helper-maven-plugin</artifactId>
<version>1.5</version>
<executions>
<execution>
<id>attach-artifacts</id>
<phase>package</phase>
<goals>
<goal>attach-artifact</goal>
</goals>
<configuration>
<artifacts>
<artifact>
<file>${project.build.outputDirectory}/log4j.xml</file>
<type>xml</type>
<classifier>log4j</classifier>
</artifact>
</artifacts>
</configuration>
</execution>
</executions>
</plugin>
Now in your war artifact, copy the xml to the output directory:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<id>copy</id>
<phase>prepare-package</phase>
<goals>
<goal>copy</goal>
</goals>
<configuration>
<artifactItems>
<artifactItem>
<groupId>${project.groupId}</groupId>
<artifactId>your.jar.project.artifactId</artifactId>
<version>${project.version}</version>
<type>xml</type>
<classifier>log4j</classifier>
<outputDirectory>${project.build.outputDirectory}
</outputDirectory>
<destFileName>log4j.xml</destFileName>
</artifactItem>
</artifactItems>
</configuration>
</execution>
</executions>
</plugin>
But of course it would be easier to just put the file in [web-artifact]/src/main/resources in the first place :-)

From my experience this can be implemented in an easy way , just :
Make the log4j configuration resource at the parent module.
Call the dependency of log4j in all pom modules.
Detailed steps:
Create a project with common-config
In the src/main/resources folder put the log4j or logback config file
Install the artifact in the local Maven repository to be used by other projects
Add the dependency as a normal Maven dependency in the subsequent projects
<dependency>
<groupId>com.your.group.id</groupId>
<artifactId>common-config</artifactId>
<scope>provided</scope>
</dependency>
I prefer to use the scope provided and provide the file from a classpath config folder at runtime.