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No main manifest attribute error - IntelliJ with Maven jar plugin

I'm following a tutorial found at this link (https://stackabuse.com/web-scraping-the-java-way/), but when it's time to package the project and run the jar, I get the "No main manifest attribute error" in the terminal when I use java -jar target/ApartmentHunt-1.0-SNAPSHOT.jar. My pom.xml looks like
<?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>org.example</groupId>
<artifactId>ApartmentHunt</artifactId>
<version>1.0-SNAPSHOT</version>
<name>ApartmentHunt</name>
<!-- FIXME change it to the project's website -->
<url>http://www.example.com</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.jsoup</groupId>
<artifactId>jsoup</artifactId>
<version>1.13.1</version>
</dependency>
</dependencies>
<build>
<pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
<plugins>
<plugin>
<groupId>org.apache.Maven.plugins</groupId>
<artifactId>Maven-shade-plugin</artifactId>
<version>3.2.0</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<transformers>
<transformer
implementation="org.apache.Maven.plugins.shade.resource.ManifestResourceTransformer">
<mainClass>org.example.App</mainClass>
</transformer>
</transformers>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
App.java has the main method and is located in src/main/java/org.exmaple and just contains a print statement. The code is exactly the same as the tutorial, but I get an error. I've cloned the repo from the tutorial and it works on my machine, so I'm not sure what is wrong with my project. This is my first time using maven for a project, and I used the maven quickstart archetype.
I've used various assembly plugins from other posts, but it didn't resolve my issue.

check your code main method is in App.java ？

Try it with maven-jar-plugin
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>org.example.App</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
and run mvn comand:
> mvn clean
> mvn install

Adding the following plugin to my pom.xml AND running mvn assembly:single fixed the issue. Although I do not understand why I cannot run mvn package to do the same thing when I specified in the plugin to occur during the packaging phase. In addition, I have to mvn compile after any source code changes. Code below
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>org.example.App</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<appendAssemblyId>false</appendAssemblyId>
</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>

Follow the instructions in this video.
When you get to the Artifact creation point (Ctrl + Shift + Alt + S) change the location of the manifest as shown here. (\src\main\resources)

How to make sure that "java" finds the all the required classes when IDE can?

I have a Maven project with only one dependency :
<dependency>
<groupId>net.sf.jasperreports</groupId>
<artifactId>jasperreports</artifactId>
<version>6.8.0</version>
</dependency>
I am using an IDE and it installed all the required dependencies itself. I have written a simple code that uses the classes from net.sf.jasperreports. To create a the package I did mvn package and it created the jar. When I try to run the jar as java -jar myjar.jar, I get an error saying Caused by: java.lang.ClassNotFoundException: net.sf.jasperreports.engine.JRDataSource
I cannot understand how to resolve this. The IDE is able to find the classes but when invoked from command-line, it fails to find the classes. Why is that? What should I do?
I even tried to keep the jasperreports-6.8.0.jar at /Library/Java/Extensions/ but that too did not work.
Here is how the pom.xml looks like:
<?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.suhail</groupId>
<artifactId>JasperCSVDataSource</artifactId>
<version>1.0-SNAPSHOT</version>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.0.2</version>
<configuration>
<archive>
<manifest>
<mainClass>com.suhail.main.CommandLineRunner</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>
<packaging>jar</packaging>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>net.sf.jasperreports</groupId>
<artifactId>jasperreports</artifactId>
<version>6.8.0</version>
</dependency>
</dependencies>
</project>

This is the part that uses the maven shade plugin in my project, which is of course totally different from yours:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>3.2.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<shadedArtifactAttached>true</shadedArtifactAttached>
<artifactSet>
<includes>
<include>org.apache.poi:poi</include>
<include>org.apache.poi:poi-ooxml</include>
<include>org.apache.poi:poi-ooxml-schemas</include>
<include>org.apache.commons:commons-collections4</include>
<include>org.apache.xmlbeans:xmlbeans</include>
<include>org.apache.commons:commons-compress</include>
</includes>
<excludes>
<!-- Exclude main jar to avoid error 'Failed to create shaded artifact,
project main artifact does not exist' -->
<exclude>${project.groupId}:${project.artifactId}</exclude>
</excludes>
</artifactSet>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.1.1</version>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
<configuration>
<appendAssemblyId>false</appendAssemblyId>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
Please note that this part of the pom.xml goes into the <plugins> ... </plugins> section, in my case it is below the maven compiler plugin and below the maven jar plugin. You can explicitly include certain dependencies or explicitly exclude certain ones.
The result will be 2 files in your target folder, I personally use the one that has the original name, the other one will have the original name extended by shaded or similar.
If you get an error stating No main manifest attribute in ... then change your configuration of the maven jar plugin as follows:
<configuration>
<archive>
<manifestFile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestFile>
</archive>
<mainClass>com.suhail.main.CommandLineRunner</mainClass>
</configuration>

Use Maven assembly plugin instead Maven jar plugin.
see what-are-the-differences-between-maven-jar-plugin-and-maven-assembly-plugin!
Maven assembly plugin creates a fully deployable package with all dependencies packed in it.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.4.1</version>
<configuration>
<!-- get all project dependencies -->
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<!-- MainClass in mainfest make a executable jar -->
<archive>
<manifest>
<mainClass>com.suhail.main.CommandLineRunner</mainClass>
</manifest>
</archive>
</configuration>
<executions>
<execution>
<id>make-assembly</id>
<!-- bind to the packaging phase -->
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>

How do i create executable from spring maven project?

I use Spring Tool Suite 4. We have a spring-boot API and we would like to create an executable (jar or war, no clue, which one i need). We have dependencies stated in pom.xml. By default this is what we have under build if you make a clean spring-boot application:
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
So my question what do i have to add so i can actually execute maven install for my executable? As of now if i run maven install (which for me the only way i know to create executable), it gives me an AssertionError. I tried to find guides online, but none of them worked.
For now i would be happy if i could even manage to execute maven install, but my plan includes the usage of config file outside of the executable also i would like to log (log4j2) next to the jar file, so i need help with those too. How to specify these in pom.xml so i can use config file from outside and to be able to log outside?

You'll want an executable jar. Add this to your pom file:
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
<configuration>
<classifier>spring-boot</classifier>
<mainClass>
specify.your.main.Class
</mainClass>
</configuration>
</execution>
</executions>
</plugin>

So I got AssertionError, because for some reason some of my tests dont work for maven (even though if i execute them they pass).
It actually matters if jar or war. In my case it has to be a war because im making an API
Also here are the minimum you have to change in pom.xml to have a chance to create executable: (this goes before dependencies inside the pom.xml)
<packaging>war</packaging>
<properties>
<java.version>11</java.version>
<maven.compiler.source>11</maven.compiler.source>
<maven.compiler.target>11</maven.compiler.target>
<forceJavacCompilerUse>true</forceJavacCompilerUse>
</properties>
The following part goes in between <build></build>.
<pluginManagement>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>your.main.class</mainClass>
</manifest>
</configuration>
</plugin>
<plugin>
<artifactId>maven-remote-resources-plugin</artifactId>
<version>1.6.0</version>
<executions>
<execution>
<id>process-remote-resources</id>
<goals>
<goal>process</goal>
</goals>
<configuration>
<resourceBundles>
<resourceBundle>org.apache:apache-jar-resource-bundle:1.0</resourceBundle>
</resourceBundles>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</pluginManagement>
To sum up I still have no idea what most of these do, but this works.

Probleme to make a JAR using External JAR with MAVEN [duplicate]

This question already has answers here:
How can I create an executable/runnable JAR with dependencies using Maven?
(33 answers)
Closed 6 years ago.
With a friend we work on a project for our school and we are at the end.
The Probleme is that with Eclipse, our java program work correctly, and with the JAR generated by eclipse too. But we need to, when you exec the command mvn package, to generate a JAR. This JAR don't find classes of External JAR, it's the first time we use Maven so can you please help me to make a good pom.xml that when we do mvn package it generat a JAR using External JAR ?
There is the pom :
<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>coo.project</groupId>
<artifactId>COO-DONJON</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>
<name>COO-DONJON</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>4.12</version>
</dependency>
<dependency>
<groupId>javazoom</groupId>
<artifactId>jlayer</artifactId>
<version>1.0.1</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<id>copy-dependencies</id>
<phase>prepare-package</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}</outputDirectory>
<overWriteReleases>true</overWriteReleases>
<overWriteSnapshots>true</overWriteSnapshots>
<overWriteIfNewer>true</overWriteIfNewer>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-javadoc-plugin</artifactId>
<version>2.10.4</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.0.2</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>coo.project.App</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>
</project>

You will have to use the Maven Assembly Plugin.
What you need is an executable jar which should contain all your dependencies. Check below for a sample code.
<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<mainClass>coo.project.App</mainClass> // your main class here.
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>
This will produce two jars. One of them will be a regular jar, and the second one will be a fat jar with -jar-with-dependencies appended to its name. This is the jar that you should be using now. This fat jar will include your code as well as all the dependencies that your code needs.
If you do this, I don't think you will have to configure the maven-dependency plugin as well as the maven jar-plugin as done in your pom.xml. You can ignore that.

You need to use Maven shade plugin to add all dependencies inside jar by creating uber/fat jar.
Check this http://howtodoinjava.com/maven/maven-shade-plugin-create-uberfat-jar-example/

Building executable jar with maven?

I am trying to generate an executable jar for a small home project called "logmanager" using maven, just like this:
How can I create an executable JAR with dependencies using Maven?
I added the snippet shown there to the pom.xml, and ran mvn assembly:assembly. It generates two jar files in logmanager/target: logmanager-0.1.0.jar, and logmanager-0.1.0-jar-with-dependencies.jar. I get an error when I double-click on the first jar:
Could not find the main class: com.gorkwobble.logmanager.LogManager. Program will exit.
A slightly different error when I double-click the jar-with-dependencies.jar:
Failed to load Main-Class manifest attribute from: C:\EclipseProjects\logmanager\target\logmanager-0.1.0-jar-with-dependencies.jar
I copied and pasted the path and classname, and checked the spelling in the POM. My main class launches fine from an eclipse launch configuration. Can someone help me figure out why my jar file won't run? Also, why are there two jars to begin with? Let me know if you need more information.
Here is the full pom.xml, for reference:
<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.gorkwobble</groupId>
<artifactId>logmanager</artifactId>
<name>LogManager</name>
<version>0.1.0</version>
<description>Systematically renames specified log files on a scheduled basis. Designed to help manage MUSHClient logging and prevent long, continuous log files.</description>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.2</version>
<!-- nothing here -->
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.2-beta-4</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<mainClass>com.gorkwobble.logmanager.LogManager</mainClass>
</manifest>
</archive>
</configuration>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.6</source>
<target>1.6</target>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<!-- commons-lang -->
<dependency>
<groupId>commons-lang</groupId>
<artifactId>commons-lang</artifactId>
<version>2.4</version>
</dependency>
<!-- Quartz scheduler -->
<dependency>
<groupId>opensymphony</groupId>
<artifactId>quartz</artifactId>
<version>1.6.3</version>
</dependency>
<!-- Quartz 1.6.0 depends on commons collections -->
<dependency>
<groupId>commons-collections</groupId>
<artifactId>commons-collections</artifactId>
<version>3.1</version>
</dependency>
<!-- Quartz 1.6.0 depends on commons logging -->
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.1</version>
</dependency>
<!-- Quartz 1.6.0 requires JTA in non J2EE environments -->
<dependency>
<groupId>javax.transaction</groupId>
<artifactId>jta</artifactId>
<version>1.1</version>
<scope>runtime</scope>
</dependency>
<!-- junitx test assertions -->
<dependency>
<groupId>junit-addons</groupId>
<artifactId>junit-addons</artifactId>
<version>1.4</version>
<scope>test</scope>
</dependency>
<!-- junit dependency; FIXME: make this a separate POM -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.1</version>
</dependency>
</dependencies>
<dependencyManagement>
</dependencyManagement>
</project>

Actually, I think that the answer given in the question you mentioned is just wrong (UPDATE - 20101106: someone fixed it, this answer refers to the version preceding the edit) and this explains, at least partially, why you run into troubles.
It generates two jar files in logmanager/target: logmanager-0.1.0.jar, and logmanager-0.1.0-jar-with-dependencies.jar.
The first one is the JAR of the logmanager module generated during the package phase by jar:jar (because the module has a packaging of type jar). The second one is the assembly generated by assembly:assembly and should contain the classes from the current module and its dependencies (if you used the descriptor jar-with-dependencies).
I get an error when I double-click on the first jar:
Could not find the main class: com.gorkwobble.logmanager.LogManager. Program will exit.
If you applied the suggested configuration of the link posted as reference, you configured the jar plugin to produce an executable artifact, something like this:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>com.gorkwobble.logmanager.LogManager</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
So logmanager-0.1.0.jar is indeed executable but 1. this is not what you want (because it doesn't have all dependencies) and 2. it doesn't contain com.gorkwobble.logmanager.LogManager (this is what the error is saying, check the content of the jar).
A slightly different error when I double-click the jar-with-dependencies.jar:
Failed to load Main-Class manifest attribute from: C:\EclipseProjects\logmanager\target\logmanager-0.1.0-jar-with-dependencies.jar
Again, if you configured the assembly plugin as suggested, you have something like this:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
With this setup, logmanager-0.1.0-jar-with-dependencies.jar contains the classes from the current module and its dependencies but, according to the error, its META-INF/MANIFEST.MF doesn't contain a Main-Class entry (its likely not the same MANIFEST.MF as in logmanager-0.1.0.jar). The jar is actually not executable, which again is not what you want.
So, my suggestion would be to remove the configuration element from the maven-jar-plugin and to configure the maven-assembly-plugin like this:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.2</version>
<!-- nothing here -->
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.2-beta-4</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<mainClass>org.sample.App</mainClass>
</manifest>
</archive>
</configuration>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
Of course, replace org.sample.App with the class you want to have executed. Little bonus, I've bound assembly:single to the package phase so you don't have to run assembly:assembly anymore. Just run mvn install and the assembly will be produced during the standard build.
So, please update your pom.xml with the configuration given above and run mvn clean install. Then, cd into the target directory and try again:
java -jar logmanager-0.1.0-jar-with-dependencies.jar
If you get an error, please update your question with it and post the content of the META-INF/MANIFEST.MF file and the relevant part of your pom.xml (the plugins configuration parts). Also please post the result of:
java -cp logmanager-0.1.0-jar-with-dependencies.jar com.gorkwobble.logmanager.LogManager
to demonstrate it's working fine on the command line (regardless of what eclipse is saying).
EDIT: For Java 6, you need to configure the maven-compiler-plugin. Add this to your pom.xml:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.6</source>
<target>1.6</target>
</configuration>
</plugin>

The answer of Pascal Thivent helped me out, too.
But if you manage your plugins within the <pluginManagement>element, you have to define the assembly again outside of the plugin management, or else the dependencies are not packed in the jar if you run mvn install.
<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>
<version>1.0.0-SNAPSHOT</version>
<packaging>jar</packaging>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.6</source>
<target>1.6</target>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.4</version>
<configuration>
<archive>
<manifest>
<mainClass>main.App</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>make-assembly</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</pluginManagement>
<plugins> <!-- did NOT work without this -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
</plugin>
</plugins>
</build>
<dependencies>
<!-- dependencies commented out to shorten example -->
</dependencies>
</project>

If you don't want execute assembly goal on package, you can use next command:
mvn package assembly:single
Here package is keyword.

Right click the project and give maven build,maven clean,maven generate resource and maven install.The jar file will automatically generate.