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import own .jar file as dependency via Maven and have install discover and retrieve it's dependencies

So this is probably a stupid question, but I have created an own library "testlib" which I want to include in other of my own Maven projects.
This is my own librarys .pom
<?xml version="1.0" encoding="UTF-8"?>
<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.test.testlib</groupId>
<artifactId>testlib</artifactId>
<version>1.0-SNAPSHOT</version>
<name>${project.groupId}:${project.artifactId}</name>
<description>testlibrary</description>
<packaging>jar</packaging>
<properties>
<maven.compiler.source>11</maven.compiler.source>
<maven.compiler.target>11</maven.compiler.target>
</properties>
<dependencies>
<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.36</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<version>2.5</version>
<configuration>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
</plugins>
</build>
</project>
In order to include my library in another new project, I have created a local repository in my new projects .pom
...
<repositories>
<repository>
<id>data-local</id>
<name>data</name>
<url>file://${project.basedir}/repo</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>com.test.testlib</groupId>
<artifactId>testlib</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
</dependencies>
...
Installing my own library "testlib" via mvn install is working fine for testlib itself. The problem is, that Maven will not detect that "testlib" requires org.slf4j, hence won't get it when I run install.
I have checked other dependencies in my .m2 folder and saw they have a .pom file with the same name as the .jar (for log4j that'd be log4j-1.2.17.pom). I tried copying testlibs .pom next to its .jar and changed the name accordinly, but that doesn't do it.
What do I have to do in order to get the same functionality as any other library from maven central? In other words, I don't want a fat .jar that has all dependencies included. I want a Maven project that adds my library as a dependency to discover that it needs sl4j and include it when mvn install is run.

Lambda error during maven build

I am using Maven build to build my project(using Eclipse IDE).
I have put jdk1.8 as default jdk, but still, I am getting an error as the source is 1.6.
Is there a configuration problem I am missing out? Please let me know?
(use -source 8 or higher to enable lambda expressions)
1. "clean install" as goals in "Run Configurations" in Eclipse.
2.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>com.mastercard.ayman</groupId>
<artifactId>Spring_MVC</artifactId>
<version>0.0.1-SNAPSHOT</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.2.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-rest-webmvc</artifactId>
<version>3.0.7.RELEASE</version>
</dependency>
</dependencies>
<repositories>
<repository>
<id>spring-libs-release</id>
<name>Spring Releases</name>
<url>https://repo.spring.io/libs-release</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
</repositories>
</project>
Compiler is JavaSE-1.8

Either set the maven-compiler-plugin as #Horst says or set the maven.compiler.source and maven.compiler.target properties like this.
<project ...>
...
<properties>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
...
</dependencies>
<build>
...
</build>
</project>

This is something I have dealt with too many times.
Could you post the following things as an answer?
Your current build command/query.
Your pom.xml code.
Your compiler version.
With these file(s) I could help you further to resolve your problem!

Setting the JDK in eclipse is only half the story, as maven manages the compiler itself.
Try adding the maven compiler plugin to you build configuration:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.2</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>

Maven isn't working with specifying Java JDK?

I am trying to specify which Java JDK version to use in Maven/IntelliJ IDEA. I want to use JDK 7, but the source always seems to compile in JDK 8. I have done quite a few things, this is the screenshot of my Project Structure settings of IntelliJ IDEA:
http://i.stack.imgur.com/wabk2.png
This is my pom.xml. As you can see, I am using properties, and the maven compiler plugin.
<?xml version="1.0" encoding="UTF-8"?>
<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>me.staticjava</groupId>
<artifactId>VillagerMerchants</artifactId>
<version>1.0-SNAPSHOT</version>
<build>
<plugins>
<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>
</plugins>
</build>
<properties>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties>
<repositories>
<repository>
<id>spigot-repo</id>
<url>http://repo.md-5.net/content/groups/public/</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>org.spigotmc</groupId>
<artifactId>spigot-api</artifactId>
<version>1.7.9-R0.3-SNAPSHOT</version>
<type>jar</type>
</dependency>
<dependency>
<groupId>org.bukkit</groupId>
<artifactId>craftbukkit</artifactId>
<version>1.7.9-R0.3-SNAPSHOT</version>
</dependency>
</dependencies>
I am not sure why, but the code ALWAYS compiles in 1.8...
Any help?
Thanks,
~StaticJava

You need to go into Settings -> Project Settings -> Maven -> Runner and check the JRE setting.
Mine is set to Use Project JDK (1.7) but it sounds like yours is set to something different.
By the way, I guess you are aware that the "language level" in your pom (1.7) is a different setting to the actual JDK you compile with. For example you can well use JDK 1.8 but compile to language level java 7... :)
Good luck.

How to set up a minimal Maven pom.xml file for a Heroku worker process in Java?

First off: I'm not a Java coder. I'm new to the Java/Maven tool chain. We're using a Java library for a project which we want to launch as a Heroku background worker.
This project relies on two external libraries, the mongodb Java driver which is available through Maven's central repo, and another third party library. I've seen the Heroku article on "unmanaged dependencies", but something else appears missing, as I get an error like: Could not find the main class: com.company.myproject.MyApp Program will exit. when I try to run the app locally according to Heroku's instructions on "Getting Started with Java".
I noticed that their pom.xml file contains a Maven plugin maven-dependency-plugin to copy dependencies, and when I check my target/classes folder, I don't see any of the dependencies.
Heroku also publishes a guide on building background workers in Java. That pom.xml contains a build assembly plugin, which seems more complex.
I'm a bit lost in all this ceremony (especially coming from Rails), and I'd like to stat with the simplest possible pom.xml to get this running. Is there a Maven archetype file for Java workers on Heroku? I'm also using NetBeans as IDE, and it would be great to use the IDE tools for this, if available, but it's a secondary priority.
Below my pom.xml so far:
<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.myproject</groupId>
<artifactId>myproject</artifactId>
<version>0.1</version>
<packaging>jar</packaging>
<name>myproject</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.mongodb</groupId>
<artifactId>mongo-java-driver</artifactId>
<version>2.7.3</version>
</dependency>
<dependency>
<groupId>org.thirdparty</groupId>
<artifactId>thirdparty</artifactId>
<version>0.2.9</version>
<scope>provided</scope>
</dependency>
</dependencies>
<repositories>
<repository>
<id>project-local</id>
<name>Project-local Repo</name>
<url>file:${project.basedir}/repo</url>
</repository>
</repositories>
</project>

You definitely need to use the maven-dependency-plugin to copy all of the dependencies into the target/dependency directory:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.4</version>
<executions>
<execution>
<id>copy-dependencies</id>
<phase>package</phase>
<goals><goal>copy-dependencies</goal></goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
Then your Procfile needs to include those dependencies in the classpath:
foo: java -cp target/classes:target/dependency/* com.myproject.Main
Where com.myproject.Main is the class name of the Java class you want to run (which must contain a public static void main method. Note that this also adds the Java classes which are compiled from src/main/java into the target/classes dir.

maven support for android projects?

I want to start a project for Android but i really like to build it using Maven. Does Google provide support for Maven or plan to support it? It would be great if anybody know at least an archetype for Maven that I can use meanwhile. Thanks in advance.

Seems like there is a maven plugin for that :-)

What I really wanted was an article like this, but i found it after the question was answered.
Update:
People at SpringSource did a Spring Android project that supports the usage of the Spring Framework in an Android environment and have Maven support. I will give it a try.
Here is an article about Spring Android and Maven using Eclipse 3.6 and Android SDK 9, split in two parts:
First part
Second part

The Android Maven plugin has been updated to support changes made in the Android SDK r14 release. You will need to adjust your POM to use the new version. I experienced an out of memory error with the new version when building my app, so note the dex jvmArguments section to allow for more available memory.
<plugin>
<groupId>com.jayway.maven.plugins.android.generation2</groupId>
<artifactId>android-maven-plugin</artifactId>
<version>3.0.0-alpha-13</version>
<configuration>
<sdk>
<platform>${android-platform}</platform>
</sdk>
<dex>
<jvmArguments>
<jvmArgument>-Xms256m</jvmArgument>
<jvmArgument>-Xmx512m</jvmArgument>
</jvmArguments>
</dex>
<deleteConflictingFiles>true</deleteConflictingFiles>
<undeployBeforeDeploy>true</undeployBeforeDeploy>
</configuration>
<extensions>true</extensions>
</plugin>
The latest version of the Android Configurator (m2e-android) for Eclipse also supports the changes in r14. Lastly, I've posted a follow up blog on the SpringSource site called Updated Maven Support for Android Projects, which goes over these updates to the tools.

Here is what I did to add maven support to an existing android project in Eclipse. I installed the 'm2e' plugin via the Eclipse market place. Then I installed the 'm2e-android' plugin. At the moment it is called 'Android Configurator for M2E' in Eclipse market place. After installing the two plugins and restarting Eclipse, right click on an existing android project-->Configure-->Convert to Maven Project. Choose a unique group id and an artifact id for your project then click finish. Copy the following contents to the pom.xml of the project and replace all the existing contents. Change the value of the 'version' tag under 'dependencies' to the SDK version you are using. Also change the value of the 'platform' tag near the end of the file to the value of your platform. Do not forget to also change the groupId, artifactId and name of the xml.
<?xml version="1.0" encoding="UTF-8"?>
<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>org.myproject</groupId>
<artifactId>MyProject</artifactId>
<version>0.1.0-SNAPSHOT</version>
<packaging>apk</packaging>
<name>MyProject</name>
<dependencies>
<dependency>
<groupId>com.google.android</groupId>
<artifactId>android</artifactId>
<version>2.3.3</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<finalName>${project.artifactId}</finalName>
<sourceDirectory>src</sourceDirectory>
<pluginManagement>
<plugins>
<plugin>
<groupId>com.jayway.maven.plugins.android.generation2</groupId>
<artifactId>android-maven-plugin</artifactId>
<version>3.3.0</version>
<extensions>true</extensions>
</plugin>
</plugins>
</pluginManagement>
<plugins>
<plugin>
<groupId>com.jayway.maven.plugins.android.generation2</groupId>
<artifactId>android-maven-plugin</artifactId>
<configuration>
<sdk>
<!-- platform or api level (api level 4 = platform 1.6)-->
<platform>10</platform>
</sdk>
</configuration>
</plugin>
</plugins>
</build>
</project>
After that right click on the project-->Maven-->Update Project. If Eclipse is complaining about errors in the xml, you may want to install maven then run
mvn clean install
from the console in the folder that contains the pom.xml file.

as #Riduidel said before, you can use com.jayway.maven.plugins.android.generation2 plugin. Note, that you don't need download any plugins, you need to have just the maven for using this plugin.
How I did it:
manually add pom.xml to your android project (to the root of project).
download apache-maven-3.1.1 and add your bin folder ( ex D:\java\apache-maven-3.1.1\bin;) to path in Environment Variables.
configure settings.xml in [Your_maven_path]\conf with next:
<pluginGroups>
<pluginGroup>com.jayway.maven.plugins.android.generation2</pluginGroup>
</pluginGroups>
Add content to pom.xml. My example:
<?xml version="1.0" encoding="UTF-8"?>
<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>com.example.ENumbers</groupId>
<artifactId>ENumbers</artifactId>
<version>1.0</version>
<packaging>apk</packaging>
<name>MainApp</name>
<properties>
<platform.version>2.2.1</platform.version>
</properties>
<dependencies>
<dependency>
<groupId>com.google.android</groupId>
<artifactId>android</artifactId>
<version>${platform.version}</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.simpleframework</groupId>
<artifactId>simple-xml</artifactId>
<version>2.7.1</version>
<scope>provided</scope>
<exclusions>
<exclusion>
<artifactId>xpp3</artifactId>
<groupId>xpp3</groupId>
</exclusion>
<exclusion>
<artifactId>stax-api</artifactId>
<groupId>stax</groupId>
</exclusion>
<exclusion>
<artifactId>stax</artifactId>
<groupId>stax</groupId>
</exclusion>
<exclusion>
<artifactId>spring-web</artifactId>
<groupId>org.springframework</groupId>
</exclusion>
<exclusion>
<artifactId>commons-logging</artifactId>
<groupId>commons-logging</groupId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<build>
<sourceDirectory>src</sourceDirectory>
<plugins>
<plugin>
<groupId>com.jayway.maven.plugins.android.generation2</groupId>
<artifactId>android-maven-plugin</artifactId>
<version>3.8.1</version>
<configuration>
<androidManifestFile>${project.basedir}/AndroidManifest.xml</androidManifestFile>
<assetsDirectory>${project.basedir}/assets</assetsDirectory>
<resourceDirectory>${project.basedir}/res</resourceDirectory>
<nativeLibrariesDirectory>${project.basedir}/src/main/native</nativeLibrariesDirectory>
<sdk>
<path>
D:\Program Files\Android\android-sdk
</path>
<platform>22</platform>
</sdk>
<undeployBeforeDeploy>true</undeployBeforeDeploy>
</configuration>
<extensions>true</extensions>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.6</source>
<target>1.6</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
Look at important <packaging>, <build> nodes, it's content and com.google.android dependency.
Now you can open Maven window in your IDE. For Intellij Idea I do it next:
Edit->Tool Windows->Maven and add your pom.xml for initializing maven directory.
That's all.