Maven adding mainClass in pom.xml with the right folder path - java

I want to get a working jar file with my maven project.
The build part is:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-checkstyle-plugin</artifactId>
<version>2.14</version>
<dependencies>
<dependency>
<groupId>com.puppycrawl.tools</groupId>
<artifactId>checkstyle</artifactId>
<version>6.4.1</version>
</dependency>
</dependencies>
<configuration>
<consoleOutput>true</consoleOutput>
<configLocation>${basedir}/src/test/resources/checkstyle_swt1.xml</configLocation>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.4</version>
<configuration>
<descriptor>src/assembly/src.xml</descriptor>
</configuration>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.0</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
<archive>
<manifest>
<addDefaultImplementationEntries>true</addDefaultImplementationEntries>
<addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
<addClasspath>true</addClasspath>
<mainClass>org.jis.Main</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
So my problem right now is that I don'T know how to implement the mainclass properly into my pom.xml and later into my jar file.
The Folder Structure is: src/main/java/org/jis/Main.java
but if I add the following line
<mainClass>src.main.java.org.jis.Main</mainClass>
It doesn't work.

First, your main class doesn't include src/main/java. Look at the package declaration in that Java file. For example, package org.jis;, then add the main class to that. In other words, it's only org.jis.Main.
You need to configure the maven-jar-plugin instead the of the maven-compiler-plugin. The jar-plugin is the one which is responsible for packaging and creating the manifest.MF.
From http://maven.apache.org/shared/maven-archiver/examples/classpath.html
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
...
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>fully.qualified.MainClass</mainClass>
</manifest>
</archive>
</configuration>
...
</plugin>
</plugins>
</build>

You may mention as below if it's a spring boot application.
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<mainClass>com.test.MainClass</mainClass>
</configuration>
</plugin>
</plugins>
</build>

Basically Maven is a framework which have a collection of maven-plugin for each and every action performed to build a project.
Each Build Phase is performed by corresponding maven-plugin using project's description Project Object Model(POM)
So maven-compiler plugin is just responsible to compile the project and it won't create the manifest file.
maven-jar-plugin is responsible for creating the manifest file of the project.

Just leaving this here for individuals who were as frustrated as I was trying to get an incredibly simple example to work.
The issue I was having is that the maven jar archiver had some bad information cached, so if you are giving it the proper main class (or in my case you don't actually need to do that with the proper maven version and settings).
Try blowing away the "target" directory if you are using IntelliJ and have one. The "target" directory being the one maven default places the jar for instance.

You have to use the fully qualified name of your main class:
<mainClass>org.jis.Main</mainClass>

It seems that some time has passed since the question but I'll share the solution I've reached for future readings.
I'm using a Maven Project in the IntellJ IDE. Even using the full path copied from the operation system like: C:\Users\Rogerio\Desktop\Script\src\main\java\Controller\MainClass.java, with or without .java or even trying the com.src... approach the main class was not found while creating the jar file for my application.
The solution was putting the CDATA tag inside the mainClass tag of the maven-jar plugin, as follows:
My file structures:
[A directory imagem structure on IntelliJ][1]
[1]: https://i.stack.imgur.com/LHCWc.jpg
Inside my maven-jar plugin on pom.xml:
`<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.4</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass><![CDATA[Controller.MainClass]]></mainClass>
</manifest>
</archive>
</configuration>
`

In case, You are using Spring Boot Application. Add the below in pom.xml
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
This will add the Main-Class entry in MANIFEST.MF file.

Related

Maven deploy:deploy-file publishes all files instead of one

I am building my Java application using Maven and the Maven Assembly Plugin to create an executable jar.
As a result, the target folder contains multiple jars and other files. However, I only want to deploy the executable jar file built via the Assembly Plugin.
To do this, I have tried to use mvn deploy:deploy-file and provided it with the following properties:
file
repositoryId
url
artifactId
groupId
version
However, when I execute the command, Maven deploys all files instead of only the executable jar.
I also tried disabling the default build step:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-deploy-plugin</artifactId>
<executions>
<!-- disable standard deploy -->
<execution>
<id>default-deploy</id>
<phase>none</phase>
</execution>
</executions>
</plugin>
The build part of my pom.xml looks like this:
<build>
<!--suppress UnresolvedMavenProperty -->
<finalName>${project.artifactId}-${BUILD_DATE}</finalName>
<sourceDirectory>src</sourceDirectory>
<resources>
<resource>
<directory>src</directory>
<filtering>true</filtering>
<excludes>
<exclude>**/*.java</exclude>
</excludes>
</resource>
</resources>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>main.PAtrackMain</mainClass>
<addDefaultImplementationEntries>true</addDefaultImplementationEntries>
<addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
</manifest>
<manifestEntries>
<!--suppress UnresolvedMavenProperty -->
<Implementation-Build>${BUILD_DATE}</Implementation-Build>
</manifestEntries>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<appendAssemblyId>true</appendAssemblyId>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-deploy-plugin</artifactId>
<executions>
<!-- disable standard deploy -->
<execution>
<id>default-deploy</id>
<phase>none</phase>
</execution>
</executions>
</plugin>
</plugins>
</build>
How can I deploy only the executable jar without the other files?
That is much simpler than you might think.
There are two kinds of artifacts, produced by maven project:
main: ${artifactId}-${version}.${packaging} - this one you would like to not publish
supplemental: everything else produced by plugins (javadoc, sources, assembly, etc)
If project/module packaging is pom, that means following:
project/module may not have main artifact, only supplemental ones
some plugins are not enabled by default (https://maven.apache.org/ref/3.8.6/maven-core/default-bindings.html - compare default bindings for pom and jar packaging)
Thus, all what you need is:
switch module packaging from jar to pom
enable missing plugins: maven-compiler-plugin, maven-resources-plugin, maven-jar-plugin, etc
extra configuration of maven-deploy-plugin is not required

Building an executable jar with maven depencies and external jars

I have an application where Im using maven dependecies and Im also using an external jar of a project which is located in my computer, the project is added to the application manually. The problem is whenever I export the project with maven, It only exports all maven dependencies, not the externatl jar that I have included manually. Is there anyway that I can export it?
Here is my pom.xml:
<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}/libs
</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>libs/</classpathPrefix>
<mainClass>
com.cristianruizblog.loginSecurity.LoginSecurityTutorialApplication
</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
Thanks for reading. If anyone can help I would be so happy!
As stated by #M. Deunum, try to get your external jar into a Maven repository to avoid enable any machine to build your jar. If this is no option, you can use the Maven system dependency scope to include the jar. Note that this is only a temporary solution as this scope has been marked as depricated.

Maven - generate war and fat jar in same module

I need generate war and fat jar (jar with all dependencies) in same pom.
I found many similar threads on this site, but still have a problem.
In my pom I set packaging to war and add the maven-war-plugin and maven-assembly-plugin:
...
<packaging>war</packaging>
....
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>2.6</version>
<configuration>
</configuration>
</plugin>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.2-beta-5</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<appendAssemblyId>false</appendAssemblyId>
</configuration>
<executions>
<execution>
<id>make-my-jar-with-dependencies</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
....
Note used maven-assembly-plugin version - 2.2-beta-5. In my tests its the only version that produce the correct jar file in this configuration. Unfortunately, it also prints many "[INFO] already added, skipping" lines and the build process takes too much time.
If I use the latest version of maven-assembly-plugin (2.6), there are no "already added" info prints and the build at least 3 times faster, but unlike in 2.2 version all my class files placed into /WEB-INF/classes/ folder (should be in root), so I cannon run any main class from this jar. All classes from dependency jars placed in root as expected.
Are there any plugin configuration parameters in the latest version that can help produce the correct jar?
You don't have to get all the classes from dependencies in your root location. Let the assembly plugin do its wonders. As far as running the main class is concerned, you can use the below code in addition to what you already have.
<project>
[...]
<build>
[...]
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.6</version>
<configuration>
[...]
<archive>
<manifest>
<mainClass>org.sample.App</mainClass> // specify your main class here.
</manifest>
</archive>
</configuration>
[...]
</plugin>
[...]
</project>

Missing JAR with Maven AddJar Plugin

When i run my jar file an it comes during runtime to access a class from a dependency (which is included by the maven-addjars-plugin), i get a java.lang.NoClassDefFoundError error.
Note: i also include some jars normaly by just specifying the dependency in the POM.xml, i only use the addjar plugin for the custom jars which i only have locally.
Part of POM.XML (If you need more information, pls tell)
<build>
<defaultGoal>install</defaultGoal>
<directory>${basedir}/target</directory>
<finalName>${project.artifactId}-${project.version}</finalName>
<pluginManagement>
<plugins>
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>Swapper</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<groupId>com.googlecode.addjars-maven-plugin</groupId>
<artifactId>addjars-maven-plugin</artifactId>
<version>1.0.5</version>
<executions>
<execution>
<goals>
<goal>add-jars</goal>
</goals>
<configuration>
<resources>
<resource>
<directory>${basedir}/my-repo</directory>
</resource>
</resources>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</pluginManagement>
</build>
....
<dependency>
<groupId>io.swagger</groupId>
<artifactId>swagger-codegen</artifactId>
<version>2.1.4-SNAPSHOT</version>
</dependency>
The swagger lib was copied into "target/com.googlecode.addjars-maven-plugin" folder which idk is the right place to have those libs since i dont see the libraries that are downloaded from maven repository. But the class is not found during runtime.
UPDATE:
When running with mvn exec instead of java -jar the program runs.
Anyone has an idea what i did wrong?

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.

Categories

Resources