Yay, my thesis is done! Now that the pressure is off and I've had my fill of playing Skyrim, I'm converting the code I wrote for my thesis from a chaotic directory built with ant to a nice maven project.
I originally had a bin directory with about 20 bash scripts that ran the various java and ruby programs used in my thesis, including the final jruby/sinatra-based web server. I am planning on moving my scripts to src/main/scripts, but I need to figure out how to handle the classpath.
I had previously just hardcoded paths in my scripts to the manually-downloaded dependencies. However, now that maven is downloading and storing all the jars I need, what's the best way to reference them from my scripts:
Should I just get the scripts to reference the full paths of various jars in the local repository like before?
Should I make the local repository directory a configuration option for my scripts and use relative paths to this directory?
Should I build a big hairy jar with all the dependencies using the maven assembly plugin and access this via the script-relative path ../../../target/*-jar-with-dependencies.jar?
Is there some better option I haven't thought of?
In your script, use the exec:java plugin to run Java classes. It will sort out the classpath based on the defined dependencies. Then you don't need to worry about it.
Relook at all the scripts that you have. Potentially you could achieve the functionality of some of them using maven exec plugin.
Besides assembly and shade plugins, you may want to look at the functionalities provided by maven dependency plugin as well.
In my project (Soluvas fb-tools/fbcli), because I use Java 6 and later (which supports wildcard classpaths), here's what I do:
#!/bin/bash
# Must run first: mvn package dependency:copy-dependencies
java -cp 'target/dependency/*:target/fbcli-1.0.0-SNAPSHOT.jar' org.jboss.weld.environment.se.StartMain "$#"
No need for manual generation of classpaths. :)
There are quite some plugin doing similar things you mentioned. Assembly plugin you mentioned is doubtless one of them (and the way you suggested is also a neat working solution).
You may want to take a look in AppAssembler and Shade. They all provide some mechanism to bundle the dependencies and produce a directly executable package.
Here is CLI example using Maven plugin exec:java as mentionned by #artbristol in another comment:
mvn exec:java -Dexec.mainClass="mypackage.MyClassWithMain" -Dexec.args="arg1 arg2"
Related
I have a project in which I am using maven-release-plugin to make periodic releases. I also have some script files like start.sh and stop.sh which helps in starting up the project with multiple steps using just one command. The script contains commands like, (but not limited to)
java -jar module-0.0.1-SNAPSHOT.jar
My problem is, when I run release plugin it updates all the POM files but does nothing to this script file. I want to update these script files as well along with POM files. These script files contain the version number exactly the same as pom file and the way I mentioned.
Currently, I am updating these files manually after each release.
Any help will be greatly appreciated.
Maven release plugin is indeed all about releasing the maven version. Maven as a build tool, builds the artifact and releases it.
It has nothing to do with various script files. So you should decide first of all:
Whether its a maven responsibility at all to deal with these scripts.
If so, you can create your own plugin that will do the changes. Or alternatively you can use filtering feature, Maven build helper plugin to get the access to the versioning information and assembly plugin to prepare the distribution.
Otherwise, I see 2 possible options:
Alternative 1
Rename the versioned artifact with something generic that doesn't really include any maven related versioning information.
In this case the script will always be the same and will run: java -jar my-module.jar
Alternative 2
Complicate the script so that it will find the file and resolve the version dynamically. Then it will memorize the path to the file in some variable and will run java -jar $here_is_the_resolved_file_with_version.jar
I'm new to Gradle. I see that Gradle lib already has a file 'groovy-all-2.4.12.jar' in lib folder and I don't seem to have any issues with tasks and or dependencies. Still, is it necessary in any scenario to install Groovy on my system on top of it?
Reason why I ask is that, when I do 'gradle -v' in command prompt, I see few warnings. Please see attached screenshot.
With gradle it is strongly recommended to use the Gradle wrapper committed into the project you are building instead of a system-wide gradle distribution (that is gradlew and not gralde). This guarantees the matching version of Gradle your project has been tested with.
With the Gradle wrapper you do not need to care about any dependencies that Grade itself needs, such as groovy and you really do not need to install anything of Gradle at all as the wrapper in your project will download all it needs on the first run.
The minimum setup for the Gradle wrapper is:
/gradlew - unix shell script
/gradlew.bat - windows batch script
/gradle/wrapper/gradle-wrapper.properties -- the properties file defining the version
/gradle/wrapper/gradle-wrapper.jar -- the minimal jar (50Kb) that takes care about the rest
The above files must be committed into your project and this is what 99% of all gradle projects do. You will find further details here https://docs.gradle.org/current/userguide/gradle_wrapper.html
I am learning about Jenkins and I have to explore some existing build jobs that others wrote (in the company that I'm working).
So I am trying to understand a job which uses mvn command.
So under the build part (inside the job), I see these details:
Maven version: 3.0.5
Root POM: pom:xml
Goals and options: clean install -U -Pnotest,docs
I'm trying to understand what this mvn command means?
I tried to google it: "clean install -U"
But I didn't find what the parameter U means.
And I don't know what is "-Pnotest,docs".
can you guide me regarding how I can find what's it? (maybe "-Pnotest,docs" is from a xml file or it's from the artifactory etc..)
Thanks a lot!!!!
-U Forces a check for miss releases and updated snapshots on remote repositories
If Maven is regularly used in your company, and you will have to work with it on a day-to-day basis, I would advise you to find a mentor (any colleague that knows the tool well and is ready to share its knowledge with you) and work with them. Maven, when you first look at it, can be quite of a mouthful and you'll learn it more efficiently with their help.
For the problem at hand, Elarbi Mohamed Aymen's answer already tells you what the -U flag corresponds to. As for -P, it is used to activate profiles (in your case notest and docs). These profiles are usually defined in the pom.xml of the project being build.
See Running Apache Maven for the basic commands, and as advised on that page run mvn -h to have the complete list of flags the command can use.
Maven is one of the mechanism how to handle the build process and check project dependencies, especially for Java.
One of the option can be to have physically included dependencies (artifacts / libs) in the project, but its not so useful- in case of new version, you have to replace the file, sometimes you are using same lib in more apps, ten you have to handle it manually in all projects.
Except this, there is the maven- it has a global repository with shared artifacts / libs , which are common used- ref. https://repo1.maven.org/maven2/.
Except this, you can make your own libs/ artifacts in this case, its a modules / applications which are reusable, then you are storing it in private repository- this is the artifactory.
When you want to build your project, in case of maven project you have pom.xml , which is like manual for maven what to do / how to build.
clean and install are common goals, clean will wipe your local maven repository, install will download them again, with parameter -U it force to download them.
You can define your own goals in pom file, eg. to "tree build"- build some dependent modules, then build parent project.
Eg. with -D you pass parameters to the maven eg.
mvn archetype:generate -DgroupId=com.mycompany.app -DartifactId=my-app
- that will generate new project, based on given archetype- "template", with the given groupID and artifactID- groupID can be eg. company name, artifactID is then the name of specific app / component.
-P,--activate-profiles <arg> Comma-delimited list of profiles
to activate
-D,--define <arg> Define a system property
I apologize if this sounds to simple (or the fact that there are other links that define this problem) - but I'm a complete beginner to Maven and even Java.
All that I'm trying to do is to run this code to see what it does:
https://github.com/semanticvectors/semanticvectors/wiki/GettingStarted
The Wiki says that uses can either download the .jar file or use the maven repo. I downloaded their .jar file and tried to run it but failed. I use this code:
java -jar /home/user/semanticvectors-5.6.jar
That .jar file didn't work for me and from other stackoverflow links, it seems that either the .jar file is not setup properly or I have a non-compatitble java version.
In any case, I've decided to try using Maven to get this running. I've installed Maven using:
sudo apt-get install maven
It seems to be working as everything was successful in setup. But now I'm not too sure what to do after. This Wiki (linked above) as go to this Maven repo site (https://oss.sonatype.org/#nexus-search;quick%7Esemanticvectors). To my understanding (and correct me if I'm wrong) I thought Maven is a super repository for developers and testers to work from the same code, so I thought I could use Maven as an alternative to running to program. Anyways, I'm open to any suggestions to get the program running to see what it does, thanks.
If you're interested in knowing more about me: I'm running a 16.04 Ubuntu system with Java 8.
The idea is that you can either build the JAR yourself - get the source from SVN and build it (using maven commands, as maven is a build tool), or you can use the existing JAR that is already "prepared" and ready for use in the maven-repository (nexus, in this case).
The result should be the same - if you use the JAR as a dependency in your code (add it to your pom.xml) or if you build it yourself.
You can learn more about Maven and things will be much clearer...
This looks like exactly what I would like:
http://d.hatena.ne.jp/Yoshiori/20081125/1227615261
(in Japanese, but should be apparent what it does from the commands and output)
Unfortunately, when I try those steps, it seems the plugin no longer exists at that location. Googling for it elsewhere also failed.
In short, what I'd like is to launch a jython shell with all of the pom file dependencies available on the Jython class path (hope I got that terminology right). I have a project with a rather complex and changing set of dependencies defined in maven. If I can just launch Jython from the same pom file, then I can experiment with and script all of those classes.
Other suggestions for easily loading maven dependencies into a jython shell?
Have a look at the maven-jython-compile-plugin. This plugin allows you to deploy a standalone project that includes jython with libraries. There is a demo project that shows how to use this plugin. Specifically, look at AbstractInitJython and InitJython in the code repository on how to launch a python/jython console. It will have all the libraries of the project, all pom dependencies and all the python libraries requested.
The sourceforge umbrella project is http://mavenjython.sourceforge.net/