Create a fat Jar file Maven Shade Plugin

By：Roy.LiuLast updated：2019-08-17

In this tutorial, we will show you how to use Maven Shade Plugin to create a Jar together with its dependency Jars into a single executable Jar file, so called fat Jar or uber Jar.

Note
Maven Shade plugin is a better plugin to create fat/uber jar, if compare with assembly plugin, because it provides class relocating feature, to avoid same class name conflict in the classpath.

1. Review a Java project

Previous Java project (dateutils) will be reused, see following folder structure

Note
This project has a single dependency – joda-time.jar

2. Pom.xml

Read below comment for self-explanatory.

pom.xml

<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.mkyong.core.utils</groupId>
    <artifactId>dateUtils</artifactId>
    <packaging>jar</packaging>
    <version>1.0-SNAPSHOT</version>
    <name>dateUtils</name>
    <url>http://maven.apache.org</url>
    <properties>
        <jdk.version>1.7</jdk.version>
        <jodatime.version>2.5</jodatime.version>
        <junit.version>4.11</junit.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>${junit.version}</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>joda-time</groupId>
            <artifactId>joda-time</artifactId>
            <version>${jodatime.version}</version>
        </dependency>
    </dependencies>
    <build>
        <finalName>dateutils</finalName>
        <plugins>
            <!-- download source code in Eclipse, best practice -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-eclipse-plugin</artifactId>
                <version>2.9</version>
                <configuration>
                    <downloadSources>true</downloadSources>
                    <downloadJavadocs>false</downloadJavadocs>
                </configuration>
            </plugin>
            <!-- Set a compiler level -->
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <source>${jdk.version}</source>
                    <target>${jdk.version}</target>
                </configuration>
            </plugin>
        <!-- Maven Shade Plugin -->
        <plugin>
          <groupId>org.apache.maven.plugins</groupId>
          <artifactId>maven-shade-plugin</artifactId>
          <version>2.3</version>
          <executions>
             <!-- Run shade goal on package phase -->
            <execution>
            <phase>package</phase>
            <goals>
                <goal>shade</goal>
            </goals>
            <configuration>
              <transformers>
                <!-- add Main-Class to manifest file -->
                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                    <mainClass>com.mkyong.core.utils.App</mainClass>
                </transformer>
              </transformers>
            </configuration>
              </execution>
          </executions>
        </plugin>
        </plugins>
    </build>
</project>

3. Package It

To produces the final Jar, just package it :

$ mvn package
[INFO] 
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ dateUtils ---
[INFO] Building jar: /Users/mkyong/dateUtils/target/dateutils.jar
[INFO] 
[INFO] --- maven-shade-plugin:2.3:shade (default) @ dateUtils ---
[INFO] Including joda-time:joda-time:jar:2.5 in the shaded jar.
[INFO] Replacing original artifact with shaded artifact.
[INFO] Replacing /Users/mkyong/dateUtils/target/dateutils.jar with /Users/mkyong/dateUtils/target/dateUtils-1.0-SNAPSHOT-shaded.jar
[INFO] Dependency-reduced POM written at: /Users/mkyong/dateUtils/dependency-reduced-pom.xml
[INFO] Dependency-reduced POM written at: /Users/mkyong/dateUtils/dependency-reduced-pom.xml
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 3.594s
[INFO] Finished at: Tue Oct 21 15:24:28 MYT 2014
[INFO] Final Memory: 17M/42M
[INFO] ------------------------------------------------------------------------

Two jar files will be created in the target folder.

dateutils.jar – Project and dependency classes in a single jar, this is what you want.
original-dateutils.jar – Only your project classes

P.S The generated dependency-reduced-pom.xml is for reference only, just ignore it.

4. Review It

List out the content of dateutils.jar

$ jar tf target/dateutils.jar 
META-INF/MANIFEST.MF
META-INF/
com/
com/mkyong/
com/mkyong/core/
com/mkyong/core/utils/
com/mkyong/core/utils/App.class
META-INF/maven/
META-INF/maven/com.mkyong.core.utils/
META-INF/maven/com.mkyong.core.utils/dateUtils/
META-INF/maven/com.mkyong.core.utils/dateUtils/pom.xml
META-INF/maven/com.mkyong.core.utils/dateUtils/pom.properties
META-INF/LICENSE.txt
META-INF/NOTICE.txt
org/
org/joda/
org/joda/time/
org/joda/time/base/
org/joda/time/base/AbstractDateTime.class
org/joda/time/base/AbstractDuration.class
//...
org/joda/time/Weeks.class
org/joda/time/YearMonth$Property.class
org/joda/time/YearMonth.class
org/joda/time/YearMonthDay$Property.class
org/joda/time/YearMonthDay.class
org/joda/time/Years.class
META-INF/maven/joda-time/
META-INF/maven/joda-time/joda-time/
META-INF/maven/joda-time/joda-time/pom.xml
META-INF/maven/joda-time/joda-time/pom.properties

MANIFEST.MF

Manifest-Version: 1.0
Build-Jdk: 1.7.0_05
Built-By: mkyong
Created-By: Apache Maven 3.1.1
Main-Class: com.mkyong.core.utils.App
Archiver-Version: Plexus Archiver

Run it

$ java -jar target/dateutils.jar

2014-10-21

References

From：一号门

Tags: fat-jar maven

Previous:Java Read a text file line by line

Next:Gradle Spring 4 MVC Hello World Example

COMMENTS