Using commons-codec in a stand-alone JAR via Maven - java

I've been recently trying to create a simple CLI tool. My flow is as follows:
created the project with Maven from the default archetype
mvn archetype:generate -DgroupId=com.mycompany.app -DartifactId=my-app -DarchetypeArtifactId=maven-archetype-quickstart -DarchetypeVersion=1.4 -DinteractiveMode=false
I build the project with mvn clean install. This creates a targets folder, containing the .jar.
To run as java -jar ./someJar.jar {INPUT}, I've had to add a few things to pom.xml, e.g.,
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</plugin>
but this works fine, until I try to add an external library. For example, I've been trying to add murmur3 hashing capability via commons-codec, by adding
<dependency>
<groupId>commons-codec</groupId>
<artifactId>commons-codec</artifactId>
<version>1.15</version>
</dependency>
to the pom.xml. Source using this is as simple as it gets:
package com.someRandomString.app;
import org.apache.commons.codec.digest.MurmurHash3;
public class hasherServiceOfSorts {
public static int murmur3_hash(final String data) {
return MurmurHash3.hash32(data);
}
}
and, upon invoking mvn clean install, actually builds fine. the issue is, when running the jar. It fails when invoking this method with
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/codec/digest/MurmurHash3
indicating the origin commons-codec is not part of the baked JAR. My question is, what am I doing wrong/how does one force maven to include external JARs in the final package (if possible). I guess the alternative would be to run via java -cp some.jar some.class.app, which I'm trying to avoid (having a single "binary" is very attractive. Thanks!

As suggested by #Jesper, using https://maven.apache.org/plugins/maven-shade-plugin/ did the trick.

Related

Manually create jar for use with maven [duplicate]

Maven 2 is driving me crazy during the experimentation / quick and dirty mock-up phase of development.
I have a pom.xml file that defines the dependencies for the web-app framework I want to use, and I can quickly generate starter projects from that file. However, sometimes I want to link to a 3rd party library that doesn't already have a pom.xml file defined, so rather than create the pom.xml file for the 3rd party lib by hand and install it, and add the dependency to my pom.xml, I would just like to tell Maven: "In addition to my defined dependencies, include any jars that are in /lib too."
It seems like this ought to be simple, but if it is, I am missing something.
Any pointers on how to do this are greatly appreciated. Short of that, if there is a simple way to point maven to a /lib directory and easily create a pom.xml with all the enclosed jars mapped to a single dependency which I could then name / install and link to in one fell swoop would also suffice.
Problems of popular approaches
Most of the answers you'll find around the internet will suggest you to either install the dependency to your local repository or specify a "system" scope in the pom and distribute the dependency with the source of your project. But both of these solutions are actually flawed.
Why you shouldn't apply the "Install to Local Repo" approach
When you install a dependency to your local repository it remains there. Your distribution artifact will do fine as long as it has access to this repository. The problem is in most cases this repository will reside on your local machine, so there'll be no way to resolve this dependency on any other machine. Clearly making your artifact depend on a specific machine is not a way to handle things. Otherwise this dependency will have to be locally installed on every machine working with that project which is not any better.
Why you shouldn't apply the "System Scope" approach
The jars you depend on with the "System Scope" approach neither get installed to any repository or attached to your target packages. That's why your distribution package won't have a way to resolve that dependency when used. That I believe was the reason why the use of system scope even got deprecated. Anyway you don't want to rely on a deprecated feature.
The static in-project repository solution
After putting this in your pom:
<repository>
<id>repo</id>
<releases>
<enabled>true</enabled>
<checksumPolicy>ignore</checksumPolicy>
</releases>
<snapshots>
<enabled>false</enabled>
</snapshots>
<url>file://${project.basedir}/repo</url>
</repository>
for each artifact with a group id of form x.y.z Maven will include the following location inside your project dir in its search for artifacts:
repo/
| - x/
| | - y/
| | | - z/
| | | | - ${artifactId}/
| | | | | - ${version}/
| | | | | | - ${artifactId}-${version}.jar
To elaborate more on this you can read this blog post.
Use Maven to install to project repo
Instead of creating this structure by hand I recommend to use a Maven plugin to install your jars as artifacts. So, to install an artifact to an in-project repository under repo folder execute:
mvn install:install-file -DlocalRepositoryPath=repo -DcreateChecksum=true -Dpackaging=jar -Dfile=[your-jar] -DgroupId=[...] -DartifactId=[...] -Dversion=[...]
If you'll choose this approach you'll be able to simplify the repository declaration in pom to:
<repository>
<id>repo</id>
<url>file://${project.basedir}/repo</url>
</repository>
A helper script
Since executing installation command for each lib is kinda annoying and definitely error prone, I've created a utility script which automatically installs all the jars from a lib folder to a project repository, while automatically resolving all metadata (groupId, artifactId and etc.) from names of files. The script also prints out the dependencies xml for you to copy-paste in your pom.
Include the dependencies in your target package
When you'll have your in-project repository created you'll have solved a problem of distributing the dependencies of the project with its source, but since then your project's target artifact will depend on non-published jars, so when you'll install it to a repository it will have unresolvable dependencies.
To beat this problem I suggest to include these dependencies in your target package. This you can do with either the Assembly Plugin or better with the OneJar Plugin. The official documentaion on OneJar is easy to grasp.
For throw away code only
set scope == system and just make up a groupId, artifactId, and version
<dependency>
<groupId>org.swinglabs</groupId>
<artifactId>swingx</artifactId>
<version>0.9.2</version>
<scope>system</scope>
<systemPath>${project.basedir}/lib/swingx-0.9.3.jar</systemPath>
</dependency>
Note: system dependencies are not copied into resulted jar/war
(see How to include system dependencies in war built using maven)
You may create local repository on your project
For example if you have libs folder in project structure
In libs folder you should create directory structure like: /groupId/artifactId/version/artifactId-version.jar
In your pom.xml you should register repository
<repository>
<id>ProjectRepo</id>
<name>ProjectRepo</name>
<url>file://${project.basedir}/libs</url>
</repository>
and add dependency as usual
<dependency>
<groupId>groupId</groupId>
<artifactId>artifactId</artifactId>
<version>version</version>
</dependency>
That is all.
For detailed information: How to add external libraries in Maven (archived)
Note: When using the System scope (as mentioned on this page), Maven needs absolute paths.
If your jars are under your project's root, you'll want to prefix your systemPath values with ${basedir}.
This is what I have done, it also works around the package issue and it works with checked out code.
I created a new folder in the project in my case I used repo, but feel free to use src/repo
In my POM I had a dependency that is not in any public maven repositories
<dependency>
<groupId>com.dovetail</groupId>
<artifactId>zoslog4j</artifactId>
<version>1.0.1</version>
<scope>runtime</scope>
</dependency>
I then created the following directories repo/com/dovetail/zoslog4j/1.0.1 and copied the JAR file into that folder.
I created the following POM file to represent the downloaded file (this step is optional, but it removes a WARNING) and helps the next guy figure out where I got the file to begin with.
<?xml version="1.0" encoding="UTF-8" ?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.dovetail</groupId>
<artifactId>zoslog4j</artifactId>
<packaging>jar</packaging>
<version>1.0.1</version>
<name>z/OS Log4J Appenders</name>
<url>http://dovetail.com/downloads/misc/index.html</url>
<description>Apache Log4j Appender for z/OS Logstreams, files, etc.</description>
</project>
Two optional files I create are the SHA1 checksums for the POM and the JAR to remove the missing checksum warnings.
shasum -b < repo/com/dovetail/zoslog4j/1.0.1/zoslog4j-1.0.1.jar \
> repo/com/dovetail/zoslog4j/1.0.1/zoslog4j-1.0.1.jar.sha1
shasum -b < repo/com/dovetail/zoslog4j/1.0.1/zoslog4j-1.0.1.pom \
> repo/com/dovetail/zoslog4j/1.0.1/zoslog4j-1.0.1.pom.sha1
Finally I add the following fragment to my pom.xml that allows me to refer to the local repository
<repositories>
<repository>
<id>project</id>
<url>file:///${basedir}/repo</url>
</repository>
</repositories>
This is how we add or install a local jar
<dependency>
<groupId>org.example</groupId>
<artifactId>iamajar</artifactId>
<version>1.0</version>
<scope>system</scope>
<systemPath>${project.basedir}/lib/iamajar.jar</systemPath>
</dependency>
i gave some default groupId and artifactId because they are mandatory :)
You really ought to get a framework in place via a repository and identifying your dependencies up front. Using the system scope is a common mistake people use, because they "don't care about the dependency management." The trouble is that doing this you end up with a perverted maven build that will not show maven in a normal condition. You would be better off following an approach like this.
Maven install plugin has command line usage to install a jar into the local repository, POM is optional but you will have to specify the GroupId, ArtifactId, Version and Packaging (all the POM stuff).
Using <scope>system</scope> is a terrible idea for reasons explained by others, installing the file manually to your local repository makes the build unreproducible, and using <url>file://${project.basedir}/repo</url> is not a good idea either because (1) that may not be a well-formed file URL (e.g. if the project is checked out in a directory with unusual characters), (2) the result is unusable if this project’s POM is used as a dependency of someone else’s project.
Assuming you are unwilling to upload the artifact to a public repository, Simeon’s suggestion of a helper module does the job. But there is an easier way now…
The Recommendation
Use non-maven-jar-maven-plugin. Does exactly what you were asking for, with none of the drawbacks of the other approaches.
I found another way to do this, see here from a Heroku post
To summarize (sorry about some copy & paste)
Create a repo directory under your root folder:
yourproject
+- pom.xml
+- src
+- repo
Run this to install the jar to your local repo directory
mvn deploy:deploy-file -Durl=file:///path/to/yourproject/repo/ -Dfile=mylib-1.0.jar -DgroupId=com.example -DartifactId=mylib -Dpackaging=jar -Dversion=1.0
Add this your pom.xml:
<repositories>
<!--other repositories if any-->
<repository>
<id>project.local</id>
<name>project</name>
<url>file:${project.basedir}/repo</url>
</repository>
</repositories>
<dependency>
<groupId>com.example</groupId>
<artifactId>mylib</artifactId>
<version>1.0</version>
</dependency>
What seems simplest to me is just configure your maven-compiler-plugin to include your custom jars. This example will load any jar files in a lib directory.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<includes>
<include>lib/*.jar</include>
</includes>
</configuration>
</plugin>
After having really long discussion with CloudBees guys about properly maven packaging of such kind of JARs, they made an interesting good proposal for a solution:
Creation of a fake Maven project which attaches a pre-existing JAR as a primary artifact, running into belonged POM install:install-file execution. Here is an example of such kinf of POM:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-install-plugin</artifactId>
<version>2.3.1</version>
<executions>
<execution>
<id>image-util-id</id>
<phase>install</phase>
<goals>
<goal>install-file</goal>
</goals>
<configuration>
<file>${basedir}/file-you-want-to-include.jar</file>
<groupId>${project.groupId}</groupId>
<artifactId>${project.artifactId}</artifactId>
<version>${project.version}</version>
<packaging>jar</packaging>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
But in order to implement it, existing project structure should be changed. First, you should have in mind that for each such kind of JAR there should be created different fake Maven project (module). And there should be created a parent Maven project including all sub-modules which are : all JAR wrappers and existing main project. The structure could be :
root project (this contains the parent POM file includes all sub-modules with module XML element) (POM packaging)
JAR 1 wrapper Maven child project (POM packaging)
JAR 2 wrapper Maven child project (POM packaging)
main existing Maven child project (WAR, JAR, EAR .... packaging)
When parent running via mvn:install or mvn:packaging is forced and sub-modules will be executed. That could be concerned as a minus here, since project structure should be changed, but offers a non static solution at the end
The problem with systemPath is that the dependencies' jars won't get distributed along your artifacts as transitive dependencies. Try what I've posted here: Is it best to Mavenize your project jar files or put them in WEB-INF/lib?
Then declare dependencies as usual.
And please read the footer note.
If you want a quick and dirty solution, you can do the following (though I do not recommend this for anything except test projects, maven will complain in length that this is not proper).
Add a dependency entry for each jar file you need, preferably with a perl script or something similar and copy/paste that into your pom file.
#! /usr/bin/perl
foreach my $n (#ARGV) {
$n=~s#.*/##;
print "<dependency>
<groupId>local.dummy</groupId>
<artifactId>$n</artifactId>
<version>0.0.1</version>
<scope>system</scope>
<systemPath>\${project.basedir}/lib/$n</systemPath>
</dependency>
";
A quick&dirty batch solution (based on Alex's answer):
libs.bat
#ECHO OFF
FOR %%I IN (*.jar) DO (
echo ^<dependency^>
echo ^<groupId^>local.dummy^</groupId^>
echo ^<artifactId^>%%I^</artifactId^>
echo ^<version^>0.0.1^</version^>
echo ^<scope^>system^</scope^>
echo ^<systemPath^>${project.basedir}/lib/%%I^</systemPath^>
echo ^</dependency^>
)
Execute it like this: libs.bat > libs.txt.
Then open libs.txt and copy its content as dependencies.
In my case, I only needed the libraries to compile my code, and this solution was the best for that purpose.
To install the 3rd party jar which is not in maven repository use maven-install-plugin.
Below are steps:
Download the jar file manually from the source (website)
Create a folder and place your jar file in it
Run the below command to install the 3rd party jar in your local maven repository
mvn install:install-file -Dfile= -DgroupId=
-DartifactId= -Dversion= -Dpackaging=
Below is the e.g one I used it for simonsite log4j
mvn install:install-file
-Dfile=/Users/athanka/git/MyProject/repo/log4j-rolling-appender.jar -DgroupId=uk.org.simonsite -DartifactId=log4j-rolling-appender -Dversion=20150607-2059 -Dpackaging=jar
In the pom.xml include the dependency as below
<dependency>
<groupId>uk.org.simonsite</groupId>
<artifactId>log4j-rolling-appender</artifactId>
<version>20150607-2059</version>
</dependency>
Run the mvn clean install command to create your packaging
Below is the reference link:
https://maven.apache.org/guides/mini/guide-3rd-party-jars-local.html
A strange solution I found:
using Eclipse
create simple (non-maven) java project
add a Main class
add all the jars to the classpath
export Runnable JAR (it's important, because no other way here to do it)
select Extract required libraries into generated JAR
decide the licence issues
tadammm...install the generated jar to your m2repo
add this single dependency to your other projects.
cheers,
Balint
Even though it does not exactly fit to your problem, I'll drop this here. My requirements were:
Jars that can not be found in an online maven repository should be in the SVN.
If one developer adds another library, the other developers should not be bothered with manually installing them.
The IDE (NetBeans in my case) should be able find the sources and javadocs to provide autocompletion and help.
Let's talk about (3) first: Just having the jars in a folder and somehow merging them into the final jar will not work for here, since the IDE will not understand this. This means all libraries have to be installed properly. However, I dont want to have everyone installing it using "mvn install-file".
In my project I needed metawidget. Here we go:
Create a new maven project (name it "shared-libs" or something like that).
Download metawidget and extract the zip into src/main/lib.
The folder doc/api contains the javadocs. Create a zip of the content (doc/api/api.zip).
Modify the pom like this
Build the project and the library will be installed.
Add the library as a dependency to your project, or (if you added the dependency in the shared-libs project) add shared-libs as dependency to get all libraries at once.
Every time you have a new library, just add a new execution and tell everyone to build the project again (you can improve this process with project hierachies).
For those that didn't find a good answer here, this is what we are doing to get a jar with all the necessary dependencies in it. This answer (https://stackoverflow.com/a/7623805/1084306) mentions to use the Maven Assembly plugin but doesn't actually give an example in the answer. And if you don't read all the way to the end of the answer (it's pretty lengthy), you may miss it. Adding the below to your pom.xml will generate target/${PROJECT_NAME}-${VERSION}-jar-with-dependencies.jar
<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>my.package.mainclass</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>
I alluded to some python code in a comment to the answer from #alex lehmann's , so am posting it here.
def AddJars(jarList):
s1 = ''
for elem in jarList:
s1+= """
<dependency>
<groupId>local.dummy</groupId>
<artifactId>%s</artifactId>
<version>0.0.1</version>
<scope>system</scope>
<systemPath>${project.basedir}/manual_jars/%s</systemPath>
</dependency>\n"""%(elem, elem)
return s1
This doesn't answer how to add them to your POM, and may be a no brainer, but would just adding the lib dir to your classpath work? I know that is what I do when I need an external jar that I don't want to add to my Maven repos.
Hope this helps.
What works in our project is what Archimedes Trajano wrote, but we had in our .m2/settings.xml something like this:
<mirror>
<id>nexus</id>
<mirrorOf>*</mirrorOf>
<url>http://url_to_our_repository</url>
</mirror>
and the * should be changed to central. So if his answer doesn't work for you, you should check your settings.xml
I just wanted a quick and dirty workaround... I couldn't run the script from Nikita Volkov: syntax error + it requires a strict format for the jar names.
I made this Perl script which works with whatever format for the jar file names, and it generates the dependencies in an xml so it can be copy pasted directly in a pom.
If you want to use it, make sure you understand what the script is doing, you may need to change the lib folder and the value for the groupId or artifactId...
#!/usr/bin/perl
use strict;
use warnings;
open(my $fh, '>', 'dependencies.xml') or die "Could not open file 'dependencies.xml' $!";
foreach my $file (glob("lib/*.jar")) {
print "$file\n";
my $groupId = "my.mess";
my $artifactId = "";
my $version = "0.1-SNAPSHOT";
if ($file =~ /\/([^\/]*?)(-([0-9v\._]*))?\.jar$/) {
$artifactId = $1;
if (defined($3)) {
$version = $3;
}
`mvn install:install-file -Dfile=$file -DgroupId=$groupId -DartifactId=$artifactId -Dversion=$version -Dpackaging=jar`;
print $fh "<dependency>\n\t<groupId>$groupId</groupId>\n\t<artifactId>$artifactId</artifactId>\n\t<version>$version</version>\n</dependency>\n";
print " => $groupId:$artifactId:$version\n";
} else {
print "##### BEUH...\n";
}
}
close $fh;
The solution for scope='system' approach in Java:
public static void main(String[] args) {
String filepath = "/Users/Downloads/lib/";
try (Stream<Path> walk = Files.walk(Paths.get(filepath))) {
List<String> result = walk.filter(Files::isRegularFile)
.map(x -> x.toString()).collect(Collectors.toList());
String indentation = " ";
for (String s : result) {
System.out.println(indentation + indentation + "<dependency>");
System.out.println(indentation + indentation + indentation + "<groupId>"
+ s.replace(filepath, "").replace(".jar", "")
+ "</groupId>");
System.out.println(indentation + indentation + indentation + "<artifactId>"
+ s.replace(filepath, "").replace(".jar", "")
+ "</artifactId>");
System.out.println(indentation + indentation + indentation + "<version>"
+ s.replace(filepath, "").replace(".jar", "")
+ "</version>");
System.out.println(indentation + indentation + indentation + "<scope>system</scope>");
System.out.println(indentation + indentation + indentation + "<systemPath>" + s + "</systemPath>");
System.out.println(indentation + indentation + "</dependency>");
}
} catch (IOException e) {
e.printStackTrace();
}
}

Maven , How to let dependency of local system jar be included into the output jar? [duplicate]

Maven 2 is driving me crazy during the experimentation / quick and dirty mock-up phase of development.
I have a pom.xml file that defines the dependencies for the web-app framework I want to use, and I can quickly generate starter projects from that file. However, sometimes I want to link to a 3rd party library that doesn't already have a pom.xml file defined, so rather than create the pom.xml file for the 3rd party lib by hand and install it, and add the dependency to my pom.xml, I would just like to tell Maven: "In addition to my defined dependencies, include any jars that are in /lib too."
It seems like this ought to be simple, but if it is, I am missing something.
Any pointers on how to do this are greatly appreciated. Short of that, if there is a simple way to point maven to a /lib directory and easily create a pom.xml with all the enclosed jars mapped to a single dependency which I could then name / install and link to in one fell swoop would also suffice.
Problems of popular approaches
Most of the answers you'll find around the internet will suggest you to either install the dependency to your local repository or specify a "system" scope in the pom and distribute the dependency with the source of your project. But both of these solutions are actually flawed.
Why you shouldn't apply the "Install to Local Repo" approach
When you install a dependency to your local repository it remains there. Your distribution artifact will do fine as long as it has access to this repository. The problem is in most cases this repository will reside on your local machine, so there'll be no way to resolve this dependency on any other machine. Clearly making your artifact depend on a specific machine is not a way to handle things. Otherwise this dependency will have to be locally installed on every machine working with that project which is not any better.
Why you shouldn't apply the "System Scope" approach
The jars you depend on with the "System Scope" approach neither get installed to any repository or attached to your target packages. That's why your distribution package won't have a way to resolve that dependency when used. That I believe was the reason why the use of system scope even got deprecated. Anyway you don't want to rely on a deprecated feature.
The static in-project repository solution
After putting this in your pom:
<repository>
<id>repo</id>
<releases>
<enabled>true</enabled>
<checksumPolicy>ignore</checksumPolicy>
</releases>
<snapshots>
<enabled>false</enabled>
</snapshots>
<url>file://${project.basedir}/repo</url>
</repository>
for each artifact with a group id of form x.y.z Maven will include the following location inside your project dir in its search for artifacts:
repo/
| - x/
| | - y/
| | | - z/
| | | | - ${artifactId}/
| | | | | - ${version}/
| | | | | | - ${artifactId}-${version}.jar
To elaborate more on this you can read this blog post.
Use Maven to install to project repo
Instead of creating this structure by hand I recommend to use a Maven plugin to install your jars as artifacts. So, to install an artifact to an in-project repository under repo folder execute:
mvn install:install-file -DlocalRepositoryPath=repo -DcreateChecksum=true -Dpackaging=jar -Dfile=[your-jar] -DgroupId=[...] -DartifactId=[...] -Dversion=[...]
If you'll choose this approach you'll be able to simplify the repository declaration in pom to:
<repository>
<id>repo</id>
<url>file://${project.basedir}/repo</url>
</repository>
A helper script
Since executing installation command for each lib is kinda annoying and definitely error prone, I've created a utility script which automatically installs all the jars from a lib folder to a project repository, while automatically resolving all metadata (groupId, artifactId and etc.) from names of files. The script also prints out the dependencies xml for you to copy-paste in your pom.
Include the dependencies in your target package
When you'll have your in-project repository created you'll have solved a problem of distributing the dependencies of the project with its source, but since then your project's target artifact will depend on non-published jars, so when you'll install it to a repository it will have unresolvable dependencies.
To beat this problem I suggest to include these dependencies in your target package. This you can do with either the Assembly Plugin or better with the OneJar Plugin. The official documentaion on OneJar is easy to grasp.
For throw away code only
set scope == system and just make up a groupId, artifactId, and version
<dependency>
<groupId>org.swinglabs</groupId>
<artifactId>swingx</artifactId>
<version>0.9.2</version>
<scope>system</scope>
<systemPath>${project.basedir}/lib/swingx-0.9.3.jar</systemPath>
</dependency>
Note: system dependencies are not copied into resulted jar/war
(see How to include system dependencies in war built using maven)
You may create local repository on your project
For example if you have libs folder in project structure
In libs folder you should create directory structure like: /groupId/artifactId/version/artifactId-version.jar
In your pom.xml you should register repository
<repository>
<id>ProjectRepo</id>
<name>ProjectRepo</name>
<url>file://${project.basedir}/libs</url>
</repository>
and add dependency as usual
<dependency>
<groupId>groupId</groupId>
<artifactId>artifactId</artifactId>
<version>version</version>
</dependency>
That is all.
For detailed information: How to add external libraries in Maven (archived)
Note: When using the System scope (as mentioned on this page), Maven needs absolute paths.
If your jars are under your project's root, you'll want to prefix your systemPath values with ${basedir}.
This is what I have done, it also works around the package issue and it works with checked out code.
I created a new folder in the project in my case I used repo, but feel free to use src/repo
In my POM I had a dependency that is not in any public maven repositories
<dependency>
<groupId>com.dovetail</groupId>
<artifactId>zoslog4j</artifactId>
<version>1.0.1</version>
<scope>runtime</scope>
</dependency>
I then created the following directories repo/com/dovetail/zoslog4j/1.0.1 and copied the JAR file into that folder.
I created the following POM file to represent the downloaded file (this step is optional, but it removes a WARNING) and helps the next guy figure out where I got the file to begin with.
<?xml version="1.0" encoding="UTF-8" ?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.dovetail</groupId>
<artifactId>zoslog4j</artifactId>
<packaging>jar</packaging>
<version>1.0.1</version>
<name>z/OS Log4J Appenders</name>
<url>http://dovetail.com/downloads/misc/index.html</url>
<description>Apache Log4j Appender for z/OS Logstreams, files, etc.</description>
</project>
Two optional files I create are the SHA1 checksums for the POM and the JAR to remove the missing checksum warnings.
shasum -b < repo/com/dovetail/zoslog4j/1.0.1/zoslog4j-1.0.1.jar \
> repo/com/dovetail/zoslog4j/1.0.1/zoslog4j-1.0.1.jar.sha1
shasum -b < repo/com/dovetail/zoslog4j/1.0.1/zoslog4j-1.0.1.pom \
> repo/com/dovetail/zoslog4j/1.0.1/zoslog4j-1.0.1.pom.sha1
Finally I add the following fragment to my pom.xml that allows me to refer to the local repository
<repositories>
<repository>
<id>project</id>
<url>file:///${basedir}/repo</url>
</repository>
</repositories>
This is how we add or install a local jar
<dependency>
<groupId>org.example</groupId>
<artifactId>iamajar</artifactId>
<version>1.0</version>
<scope>system</scope>
<systemPath>${project.basedir}/lib/iamajar.jar</systemPath>
</dependency>
i gave some default groupId and artifactId because they are mandatory :)
You really ought to get a framework in place via a repository and identifying your dependencies up front. Using the system scope is a common mistake people use, because they "don't care about the dependency management." The trouble is that doing this you end up with a perverted maven build that will not show maven in a normal condition. You would be better off following an approach like this.
Maven install plugin has command line usage to install a jar into the local repository, POM is optional but you will have to specify the GroupId, ArtifactId, Version and Packaging (all the POM stuff).
Using <scope>system</scope> is a terrible idea for reasons explained by others, installing the file manually to your local repository makes the build unreproducible, and using <url>file://${project.basedir}/repo</url> is not a good idea either because (1) that may not be a well-formed file URL (e.g. if the project is checked out in a directory with unusual characters), (2) the result is unusable if this project’s POM is used as a dependency of someone else’s project.
Assuming you are unwilling to upload the artifact to a public repository, Simeon’s suggestion of a helper module does the job. But there is an easier way now…
The Recommendation
Use non-maven-jar-maven-plugin. Does exactly what you were asking for, with none of the drawbacks of the other approaches.
I found another way to do this, see here from a Heroku post
To summarize (sorry about some copy & paste)
Create a repo directory under your root folder:
yourproject
+- pom.xml
+- src
+- repo
Run this to install the jar to your local repo directory
mvn deploy:deploy-file -Durl=file:///path/to/yourproject/repo/ -Dfile=mylib-1.0.jar -DgroupId=com.example -DartifactId=mylib -Dpackaging=jar -Dversion=1.0
Add this your pom.xml:
<repositories>
<!--other repositories if any-->
<repository>
<id>project.local</id>
<name>project</name>
<url>file:${project.basedir}/repo</url>
</repository>
</repositories>
<dependency>
<groupId>com.example</groupId>
<artifactId>mylib</artifactId>
<version>1.0</version>
</dependency>
What seems simplest to me is just configure your maven-compiler-plugin to include your custom jars. This example will load any jar files in a lib directory.
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<includes>
<include>lib/*.jar</include>
</includes>
</configuration>
</plugin>
After having really long discussion with CloudBees guys about properly maven packaging of such kind of JARs, they made an interesting good proposal for a solution:
Creation of a fake Maven project which attaches a pre-existing JAR as a primary artifact, running into belonged POM install:install-file execution. Here is an example of such kinf of POM:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-install-plugin</artifactId>
<version>2.3.1</version>
<executions>
<execution>
<id>image-util-id</id>
<phase>install</phase>
<goals>
<goal>install-file</goal>
</goals>
<configuration>
<file>${basedir}/file-you-want-to-include.jar</file>
<groupId>${project.groupId}</groupId>
<artifactId>${project.artifactId}</artifactId>
<version>${project.version}</version>
<packaging>jar</packaging>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
But in order to implement it, existing project structure should be changed. First, you should have in mind that for each such kind of JAR there should be created different fake Maven project (module). And there should be created a parent Maven project including all sub-modules which are : all JAR wrappers and existing main project. The structure could be :
root project (this contains the parent POM file includes all sub-modules with module XML element) (POM packaging)
JAR 1 wrapper Maven child project (POM packaging)
JAR 2 wrapper Maven child project (POM packaging)
main existing Maven child project (WAR, JAR, EAR .... packaging)
When parent running via mvn:install or mvn:packaging is forced and sub-modules will be executed. That could be concerned as a minus here, since project structure should be changed, but offers a non static solution at the end
The problem with systemPath is that the dependencies' jars won't get distributed along your artifacts as transitive dependencies. Try what I've posted here: Is it best to Mavenize your project jar files or put them in WEB-INF/lib?
Then declare dependencies as usual.
And please read the footer note.
If you want a quick and dirty solution, you can do the following (though I do not recommend this for anything except test projects, maven will complain in length that this is not proper).
Add a dependency entry for each jar file you need, preferably with a perl script or something similar and copy/paste that into your pom file.
#! /usr/bin/perl
foreach my $n (#ARGV) {
$n=~s#.*/##;
print "<dependency>
<groupId>local.dummy</groupId>
<artifactId>$n</artifactId>
<version>0.0.1</version>
<scope>system</scope>
<systemPath>\${project.basedir}/lib/$n</systemPath>
</dependency>
";
A quick&dirty batch solution (based on Alex's answer):
libs.bat
#ECHO OFF
FOR %%I IN (*.jar) DO (
echo ^<dependency^>
echo ^<groupId^>local.dummy^</groupId^>
echo ^<artifactId^>%%I^</artifactId^>
echo ^<version^>0.0.1^</version^>
echo ^<scope^>system^</scope^>
echo ^<systemPath^>${project.basedir}/lib/%%I^</systemPath^>
echo ^</dependency^>
)
Execute it like this: libs.bat > libs.txt.
Then open libs.txt and copy its content as dependencies.
In my case, I only needed the libraries to compile my code, and this solution was the best for that purpose.
To install the 3rd party jar which is not in maven repository use maven-install-plugin.
Below are steps:
Download the jar file manually from the source (website)
Create a folder and place your jar file in it
Run the below command to install the 3rd party jar in your local maven repository
mvn install:install-file -Dfile= -DgroupId=
-DartifactId= -Dversion= -Dpackaging=
Below is the e.g one I used it for simonsite log4j
mvn install:install-file
-Dfile=/Users/athanka/git/MyProject/repo/log4j-rolling-appender.jar -DgroupId=uk.org.simonsite -DartifactId=log4j-rolling-appender -Dversion=20150607-2059 -Dpackaging=jar
In the pom.xml include the dependency as below
<dependency>
<groupId>uk.org.simonsite</groupId>
<artifactId>log4j-rolling-appender</artifactId>
<version>20150607-2059</version>
</dependency>
Run the mvn clean install command to create your packaging
Below is the reference link:
https://maven.apache.org/guides/mini/guide-3rd-party-jars-local.html
A strange solution I found:
using Eclipse
create simple (non-maven) java project
add a Main class
add all the jars to the classpath
export Runnable JAR (it's important, because no other way here to do it)
select Extract required libraries into generated JAR
decide the licence issues
tadammm...install the generated jar to your m2repo
add this single dependency to your other projects.
cheers,
Balint
Even though it does not exactly fit to your problem, I'll drop this here. My requirements were:
Jars that can not be found in an online maven repository should be in the SVN.
If one developer adds another library, the other developers should not be bothered with manually installing them.
The IDE (NetBeans in my case) should be able find the sources and javadocs to provide autocompletion and help.
Let's talk about (3) first: Just having the jars in a folder and somehow merging them into the final jar will not work for here, since the IDE will not understand this. This means all libraries have to be installed properly. However, I dont want to have everyone installing it using "mvn install-file".
In my project I needed metawidget. Here we go:
Create a new maven project (name it "shared-libs" or something like that).
Download metawidget and extract the zip into src/main/lib.
The folder doc/api contains the javadocs. Create a zip of the content (doc/api/api.zip).
Modify the pom like this
Build the project and the library will be installed.
Add the library as a dependency to your project, or (if you added the dependency in the shared-libs project) add shared-libs as dependency to get all libraries at once.
Every time you have a new library, just add a new execution and tell everyone to build the project again (you can improve this process with project hierachies).
For those that didn't find a good answer here, this is what we are doing to get a jar with all the necessary dependencies in it. This answer (https://stackoverflow.com/a/7623805/1084306) mentions to use the Maven Assembly plugin but doesn't actually give an example in the answer. And if you don't read all the way to the end of the answer (it's pretty lengthy), you may miss it. Adding the below to your pom.xml will generate target/${PROJECT_NAME}-${VERSION}-jar-with-dependencies.jar
<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>my.package.mainclass</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>
I alluded to some python code in a comment to the answer from #alex lehmann's , so am posting it here.
def AddJars(jarList):
s1 = ''
for elem in jarList:
s1+= """
<dependency>
<groupId>local.dummy</groupId>
<artifactId>%s</artifactId>
<version>0.0.1</version>
<scope>system</scope>
<systemPath>${project.basedir}/manual_jars/%s</systemPath>
</dependency>\n"""%(elem, elem)
return s1
This doesn't answer how to add them to your POM, and may be a no brainer, but would just adding the lib dir to your classpath work? I know that is what I do when I need an external jar that I don't want to add to my Maven repos.
Hope this helps.
What works in our project is what Archimedes Trajano wrote, but we had in our .m2/settings.xml something like this:
<mirror>
<id>nexus</id>
<mirrorOf>*</mirrorOf>
<url>http://url_to_our_repository</url>
</mirror>
and the * should be changed to central. So if his answer doesn't work for you, you should check your settings.xml
I just wanted a quick and dirty workaround... I couldn't run the script from Nikita Volkov: syntax error + it requires a strict format for the jar names.
I made this Perl script which works with whatever format for the jar file names, and it generates the dependencies in an xml so it can be copy pasted directly in a pom.
If you want to use it, make sure you understand what the script is doing, you may need to change the lib folder and the value for the groupId or artifactId...
#!/usr/bin/perl
use strict;
use warnings;
open(my $fh, '>', 'dependencies.xml') or die "Could not open file 'dependencies.xml' $!";
foreach my $file (glob("lib/*.jar")) {
print "$file\n";
my $groupId = "my.mess";
my $artifactId = "";
my $version = "0.1-SNAPSHOT";
if ($file =~ /\/([^\/]*?)(-([0-9v\._]*))?\.jar$/) {
$artifactId = $1;
if (defined($3)) {
$version = $3;
}
`mvn install:install-file -Dfile=$file -DgroupId=$groupId -DartifactId=$artifactId -Dversion=$version -Dpackaging=jar`;
print $fh "<dependency>\n\t<groupId>$groupId</groupId>\n\t<artifactId>$artifactId</artifactId>\n\t<version>$version</version>\n</dependency>\n";
print " => $groupId:$artifactId:$version\n";
} else {
print "##### BEUH...\n";
}
}
close $fh;
The solution for scope='system' approach in Java:
public static void main(String[] args) {
String filepath = "/Users/Downloads/lib/";
try (Stream<Path> walk = Files.walk(Paths.get(filepath))) {
List<String> result = walk.filter(Files::isRegularFile)
.map(x -> x.toString()).collect(Collectors.toList());
String indentation = " ";
for (String s : result) {
System.out.println(indentation + indentation + "<dependency>");
System.out.println(indentation + indentation + indentation + "<groupId>"
+ s.replace(filepath, "").replace(".jar", "")
+ "</groupId>");
System.out.println(indentation + indentation + indentation + "<artifactId>"
+ s.replace(filepath, "").replace(".jar", "")
+ "</artifactId>");
System.out.println(indentation + indentation + indentation + "<version>"
+ s.replace(filepath, "").replace(".jar", "")
+ "</version>");
System.out.println(indentation + indentation + indentation + "<scope>system</scope>");
System.out.println(indentation + indentation + indentation + "<systemPath>" + s + "</systemPath>");
System.out.println(indentation + indentation + "</dependency>");
}
} catch (IOException e) {
e.printStackTrace();
}
}

executable jar for selenium testng maven project which dont have a main class

I have a Selenium TestNG project created with maven. ``
There is no main class for this prject
Using TestNg.xml file and the same is configured in pom.xml file.
Ran 'maven test' from eclispe and the test runs successfully based on the classes defined in testng.xml. no issues here
Tried the same from command prompt using mvn test from the project folder and it ran succesfully. no issues here too.
My requirement : Now i want to package this project either to executable jar or are there are any option to make a executable file so that i can schedule the run using a batch file.
To do this I ran the 'mvn package' command and it generated the jar file in the target folder. Now when i try to run this as java -jar myproj-0.0.1-SNAPSHOT.jar i get the message as "no main manifest attribute, in myproj-0.0.1-SNAPSHOT.jar". This is expected behavior since there is no main class in my case.
So i created a main class with just one line to print "text" and added the mainClass below entry in pom.xml
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<archive>
<manifest>
<mainClass>mainPackage.MainOne</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
Then i ran mvn package and it generated the new jar.
Then went to target folder of my project and ran the command as java -jar myProj.jar mainPackage.MainOne, it ran and just printed "text". MY TestNG tests did not run. It just ran main class :(..
What should i do?
Just to let you know that i have found a solution as provided in this How to programmatically call a Maven-task
as i mentioned I did use the main class. So i did the below
-Added the maven-invoker dependency in pom.xml
<dependency>
<groupId>org.apache.maven.shared</groupId>
<artifactId>maven-invoker</artifactId>
<version>2.1.1</version>
</dependency>
Updated my main class class as below using this link- http://maven.apache.org/shared/maven-invoker/usage.html
public class MainOne {
public static void main(String[] args) {
InvocationRequest request = new DefaultInvocationRequest();
request.setPomFile( new File( "pom.xml" ));
request.setGoals( Collections.singletonList( "install" ));
Invoker invoker = new DefaultInvoker();
invoker.setMavenHome(new File(System.getenv("MAVEN_HOME")));
try {
invoker.execute( request );
} catch (MavenInvocationException e) {
e.printStackTrace();
}
}
}
Then from command prompt ran the command mvn clean package shade:shade
This created the jar in the target folder.
Copied the jar into Project folder and ran the command java -jar myproj-0.0.1-SNAPSHOT.jar, my tests starting running perfectly!!.
I did something similar with JUnit. I run my tests programmatically from main method. I don't know TestNG but you can look here how to do this - Running TestNG programmatically

When I use the maven-release-plugin to release a branch, why does it try to create the branch from revision 0?

I'm using the maven-release-plugin. I'm trying to release a branch and it's failing when it tries to execute this command:
cmd.exe /X /C "svn --non-interactive copy --file C:\Users\USER~1\AppData\Local\Temp\maven-scm-711744598.commit --parents --revision 0 https://domain/svn/app/branches/2.4.8.x https://domain/svn/app/tags/App-2.4.8.1"
It gives this error:
svn: E195012: Unable to find repository location for 'https://domain/svn/app/branches/2.4.8.x' in revision 0
I think this is happening in the prepare goal because when it fails it says:
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-release-plugin:2.5:prepare
I asked a svn expert about this, and he said:
wait, why is it trying to copy something from r0? By definition there is nothing in r0. r0 is always an empty repository, the first objects are added in r1. That's why it fails. the question is why maven tried it. If you supply a revision argument to 'svn copy' then the branch / tag you create is based on the source from the revision you specify so the source has to exist in that revision (if you don't specify, you get HEAD, i.e., the newest revision) ...and as for that, I know nothing about maven or its plugins
So why is maven trying to copy from revision 0? This is the maven command I ran:
mvn --batch-mode release:prepare release:perform
And my root pom has the maven-release-plugin defined like this:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-release-plugin</artifactId>
<version>2.5</version>
<configuration>
<autoVersionSubmodules>true</autoVersionSubmodules>
<developmentVersion>2.4.8.2-SNAPSHOT</developmentVersion>
<releaseVersion>2.4.8.1</releaseVersion>
<branchBase>https://domain/svn/app/branches</branchBase>
<tagBase>https://domain/svn/app/tags</tagBase>
</configuration>
</plugin>
Also, my scm tag looks like this:
<scm>
<connection>scm:svn:https://domain/svn/app/branches/2.4.8.x</connection>
</scm>
My svn version is 1.8.5 (r1542147)
Just wanted to add this late answer for if anyone has the same problem and the solution in the comment doesn't work.
We had the same problem in a multi module application, only our parent POM had the SCM tag (which worked perfectly in our other applications). We got the same error but could solve it by adding the corresponding SCM tag to each child POM. We never found out why this was...
As I said as a comment above:
I cleaned up EVERYTHING and ran just release:prepare by itself and it succeeded without issue. Perhaps this is a bug where running release:prepare and release:perform together will cause this
I have not run into this issue since running these commands separately.
I also had this problem. In the affected project I had a custom search and replace of some files during the validate phase and I wanted to check in the changes to Svn before tagging so I added a custom check-in action like this:
<plugin>
<artifactId>maven-release-plugin</artifactId>
<configuration>
<preparationGoals>clean verify scm:checkin -Dmessage="perform release"</preparationGoals>
</configuration>
</plugin>
This had the consequences that when the release plugin tried to check in the changes in the pom file, there were no changes since they were already committed by the custom action. Thus causing this error.
I added a "includes" file list to my custom scm:checkin which only included the files that I had been tampering with and this fixed the problem for me.
The resulting configuration looked like this:
<plugin>
<artifactId>maven-release-plugin</artifactId>
<configuration>
<preparationGoals>clean verify scm:checkin -Dmessage="perform release" -Dincludes="TwogWebUtilsGrailsPlugin.groovy,plugin.xml" -DconnectionType="connection"</preparationGoals>
</configuration>
</plugin>
The reason for my custom replace action is because the project is a Grails plugin and I was following the guidelines in this blog post.
LATE EDIT: After upgrading to maven 3.2, this solution seems to break. I am back to where I started.

Retrieve version from maven pom.xml in code

What is the simplest way to retrieve version number from maven's pom.xml in code, i.e., programatically?
Assuming you're using Java, you can:
Create a .properties file in (most commonly) your src/main/resources directory (but in step 4 you could tell it to look elsewhere).
Set the value of some property in your .properties file using the standard Maven property for project version:
foo.bar=${project.version}
In your Java code, load the value from the properties file as a resource from the classpath (google for copious examples of how to do this, but here's an example for starters).
In Maven, enable resource filtering. This will cause Maven to copy that file into your output classes and translate the resource during that copy, interpreting the property. You can find some info here but you mostly just do this in your pom:
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
You can also get to other standard properties like project.name, project.description, or even arbitrary properties you put in your pom <properties>, etc. Resource filtering, combined with Maven profiles, can give you variable build behavior at build time. When you specify a profile at runtime with -PmyProfile, that can enable properties that then can show up in your build.
The accepted answer may be the best and most stable way to get a version number into an application statically, but does not actually answer the original question: How to retrieve the artifact's version number from pom.xml? Thus, I want to offer an alternative showing how to do it dynamically during runtime:
You can use Maven itself. To be more exact, you can use a Maven library.
<dependency>
<groupId>org.apache.maven</groupId>
<artifactId>maven-model</artifactId>
<version>3.3.9</version>
</dependency>
And then do something like this in Java:
package de.scrum_master.app;
import org.apache.maven.model.Model;
import org.apache.maven.model.io.xpp3.MavenXpp3Reader;
import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
import java.io.FileReader;
import java.io.IOException;
public class Application {
public static void main(String[] args) throws IOException, XmlPullParserException {
MavenXpp3Reader reader = new MavenXpp3Reader();
Model model = reader.read(new FileReader("pom.xml"));
System.out.println(model.getId());
System.out.println(model.getGroupId());
System.out.println(model.getArtifactId());
System.out.println(model.getVersion());
}
}
The console log is as follows:
de.scrum-master.stackoverflow:my-artifact:jar:1.0-SNAPSHOT
de.scrum-master.stackoverflow
my-artifact
1.0-SNAPSHOT
Update 2017-10-31: In order to answer Simon Sobisch's follow-up question I modified the example like this:
package de.scrum_master.app;
import org.apache.maven.model.Model;
import org.apache.maven.model.io.xpp3.MavenXpp3Reader;
import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Application {
public static void main(String[] args) throws IOException, XmlPullParserException {
MavenXpp3Reader reader = new MavenXpp3Reader();
Model model;
if ((new File("pom.xml")).exists())
model = reader.read(new FileReader("pom.xml"));
else
model = reader.read(
new InputStreamReader(
Application.class.getResourceAsStream(
"/META-INF/maven/de.scrum-master.stackoverflow/aspectj-introduce-method/pom.xml"
)
)
);
System.out.println(model.getId());
System.out.println(model.getGroupId());
System.out.println(model.getArtifactId());
System.out.println(model.getVersion());
}
}
Packaged artifacts contain a META-INF/maven/${groupId}/${artifactId}/pom.properties file which content looks like:
#Generated by Maven
#Sun Feb 21 23:38:24 GMT 2010
version=2.5
groupId=commons-lang
artifactId=commons-lang
Many applications use this file to read the application/jar version at runtime, there is zero setup required.
The only problem with the above approach is that this file is (currently) generated during the package phase and will thus not be present during tests, etc (there is a Jira issue to change this, see MJAR-76). If this is an issue for you, then the approach described by Alex is the way to go.
There is also the method described in Easy way to display your apps version number using Maven:
Add this to pom.xml
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>test.App</mainClass>
<addDefaultImplementationEntries>
true
</addDefaultImplementationEntries>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>
Then use this:
App.class.getPackage().getImplementationVersion()
I have found this method to be simpler.
If you use mvn packaging such as jar or war, use:
getClass().getPackage().getImplementationVersion()
It reads a property "Implementation-Version" of the generated META-INF/MANIFEST.MF (that is set to the pom.xml's version) in the archive.
To complement what #kieste has posted, which I think is the best way to have Maven build informations available in your code if you're using Spring-boot: the documentation at http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#production-ready-application-info is very useful.
You just need to activate actuators, and add the properties you need in your application.properties or application.yml
Automatic property expansion using Maven
You can automatically expand info properties from the Maven project using resource filtering. If you use the spring-boot-starter-parent you can then refer to your Maven ‘project properties’ via #..# placeholders, e.g.
project.artifactId=myproject
project.name=Demo
project.version=X.X.X.X
project.description=Demo project for info endpoint
info.build.artifact=#project.artifactId#
info.build.name=#project.name#
info.build.description=#project.description#
info.build.version=#project.version#
When using spring boot, this link might be useful: https://docs.spring.io/spring-boot/docs/2.3.x/reference/html/howto.html#howto-properties-and-configuration
With spring-boot-starter-parent you just need to add the following to your application config file:
# get values from pom.xml
pom.version=#project.version#
After that the value is available like this:
#Value("${pom.version}")
private String pomVersion;
Sometimes the Maven command line is sufficient when scripting something related to the project version, e.g. for artifact retrieval via URL from a repository:
mvn help:evaluate -Dexpression=project.version -q -DforceStdout
Usage example:
VERSION=$( mvn help:evaluate -Dexpression=project.version -q -DforceStdout )
ARTIFACT_ID=$( mvn help:evaluate -Dexpression=project.artifactId -q -DforceStdout )
GROUP_ID_URL=$( mvn help:evaluate -Dexpression=project.groupId -q -DforceStdout | sed -e 's#\.#/#g' )
curl -f -S -O http://REPO-URL/mvn-repos/${GROUP_ID_URL}/${ARTIFACT_ID}/${VERSION}/${ARTIFACT_ID}-${VERSION}.jar
Use this Library for the ease of a simple solution. Add to the manifest whatever you need and then query by string.
System.out.println("JAR was created by " + Manifests.read("Created-By"));
http://manifests.jcabi.com/index.html
<build>
<finalName>${project.artifactId}-${project.version}</finalName>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-war-plugin</artifactId>
<version>3.2.2</version>
<configuration>
<failOnMissingWebXml>false</failOnMissingWebXml>
<archive>
<manifest>
<addDefaultImplementationEntries>true</addDefaultImplementationEntries>
<addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
Get Version using this.getClass().getPackage().getImplementationVersion()
PS Don't forget to add:
<manifest>
<addDefaultImplementationEntries>true</addDefaultImplementationEntries>
<addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
</manifest>
Step 1: If you are using Spring Boot, your pom.xml should already contain spring-boot-maven-plugin. You just need to add the following configuration.
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<id>build-info</id>
<goals>
<goal>build-info</goal>
</goals>
</execution>
</executions>
</plugin>
It instructs the plugin to execute also build-info goal, which is not run by default. This generates build meta-data about your application, which includes artifact version, build time and more.
Step2: Accessing Build Properties with buildProperties bean. In our case we create a restResource to access to this build info in our webapp
#RestController
#RequestMapping("/api")
public class BuildInfoResource {
#Autowired
private BuildProperties buildProperties;
#GetMapping("/build-info")
public ResponseEntity<Map<String, Object>> getBuildInfo() {
Map<String, String> buildInfo = new HashMap();
buildInfo.put("appName", buildProperties.getName());
buildInfo.put("appArtifactId", buildProperties.getArtifact());
buildInfo.put("appVersion", buildProperties.getVersion());
buildInfo.put("appBuildDateTime", buildProperties.getTime());
return ResponseEntity.ok().body(buldInfo);
}
}
I hope this will help
I had the same problem in my daytime job. Even though many of the answers will help to find the version for a specific artifact, we needed to get the version for modules/jars that are not a direct dependency of the application. The classpath is assembled from multiple modules when the application starts, the main application module has no knowledge of how many jars are added later.
That's why I came up with a different solution, which may be a little more elegant than having to read XML or properties from jar files.
The idea
use a Java service loader approach to be able to add as many components/artifacts later, which can contribute their own versions at runtime. Create a very lightweight library with just a few lines of code to read, find, filter and sort all of the artifact versions on the classpath.
Create a maven source code generator plugin that generates the service implementation for each of the modules at compile time, package a very simple service in each of the jars.
The solution
Part one of the solution is the artifact-version-service library, which can be found on github and MavenCentral now. It covers the service definition and a few ways to get the artifact versions at runtime.
Part two is the artifact-version-maven-plugin, which can also be found on github and MavenCentral. It is used to have a hassle-free generator implementing the service definition for each of the artifacts.
Examples
Fetching all modules with coordinates
No more reading jar manifests, just a simple method call:
// iterate list of artifact dependencies
for (Artifact artifact : ArtifactVersionCollector.collectArtifacts()) {
// print simple artifact string example
System.out.println("artifact = " + artifact);
}
A sorted set of artifacts is returned. To modify the sorting order, provide a custom comparator:
new ArtifactVersionCollector(Comparator.comparing(Artifact::getVersion)).collect();
This way the list of artifacts is returned sorted by version numbers.
Find a specific artifact
ArtifactVersionCollector.findArtifact("de.westemeyer", "artifact-version-service");
Fetches the version details for a specific artifact.
Find artifacts with matching groupId(s)
Find all artifacts with groupId de.westemeyer (exact match):
ArtifactVersionCollector.findArtifactsByGroupId("de.westemeyer", true);
Find all artifacts where groupId starts with de.westemeyer:
ArtifactVersionCollector.findArtifactsByGroupId("de.westemeyer", false);
Sort result by version number:
new ArtifactVersionCollector(Comparator.comparing(Artifact::getVersion)).artifactsByGroupId("de.", false);
Implement custom actions on list of artifacts
By supplying a lambda, the very first example could be implemented like this:
ArtifactVersionCollector.iterateArtifacts(a -> {
System.out.println(a);
return false;
});
Installation
Add these two tags to all pom.xml files, or maybe to a company master pom somewhere:
<build>
<plugins>
<plugin>
<groupId>de.westemeyer</groupId>
<artifactId>artifact-version-maven-plugin</artifactId>
<version>1.1.0</version>
<executions>
<execution>
<goals>
<goal>generate-service</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>de.westemeyer</groupId>
<artifactId>artifact-version-service</artifactId>
<version>1.1.0</version>
</dependency>
</dependencies>
Feedback
It would be great if maybe some people could give the solution a try. Getting feedback about whether you think the solution fits your needs would be even better. So please don't hesitate to add a new issue on any of the github projects if you have any suggestions, feature requests, problems, whatsoever.
Licence
All of the source code is open source, free to use even for commercial products (MIT licence).
It's very easy and no configuration is needed if you use Spring with Maven.
According to the “Automatic Property Expansion Using Maven” official documentation you can automatically expand properties from the Maven project by using resource filtering. If you use the spring-boot-starter-parent, you can then refer to your Maven ‘project properties’ with #..# placeholders, as shown in the following example:
project.version=#project.version#
project.artifactId=#project.artifactId#
And you can retrieve it with #Value annotation in any class:
#Value("${project.artifactId}#${project.version}")
private String RELEASE;
I hope this helps!
With reference to ketankk's answer:
Unfortunately, adding this messed with how my application dealt with resources:
<build>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
But using this inside maven-assemble-plugin's < manifest > tag did the trick:
<addDefaultImplementationEntries>true</addDefaultImplementationEntries>
<addDefaultSpecificationEntries>true</addDefaultSpecificationEntries>
So I was able to get version using
String version = getClass().getPackage().getImplementationVersion();
Preface: Because I remember this often referred-to question after having answered it a few years ago, showing a dynamic version actually accessing Maven POM infos dynamically (e.g. also during tests), today I found a similar question which involved accessing module A's Maven info from another module B.
I thought about it for a moment and spontaneously had the idea to use a special annotation, applying it to a package declaration in package-info.java. I also created a multi-module example project on GitHub. I do not want to repeat the whole answer, so please see solution B in this answer. The Maven setup involves Templating Maven Plugin, but could also be solved in a more verbose way using a combination of resource filtering and adding generated sources directory to the build via Build Helper Maven. I wanted to avoid that, so I simply used Templating Maven.
Accepted answer worked for me once in the step #2 I changed ${project.version} to ${pom.version}

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