I'm working on scala project, where I'm using some third party libraries and those libraries are available at centralized repository (I've a url to download those).
May I know please, how scala know from where to download dependencies ? Where I can use repo url to download dependencies in scala project ?
Like in case of java, I used to mention jars repo url in setting.xml file, from where It could fetch too dependencies.
Related
I just recently used Github, and when I was trying to upload my java project I realized that I was using some external libraries like apahce poi in this project, and these files have to be stored in libs for my application to function, do I need to upload these files because I realize that might violate some issues(maybe ?).
If yes, then what is the correct way to upload or maybe just post a link to those dependency
Use a tool that provides a dependency management system such as Maven or Gradle (these are both common choices in the Java ecosystem). Your project will then include a configuration file that Maven or Gradle will use to download dependencies so you don't need to distribute them with your project.
I have started reading and trying maven since yesterday. But its making me go crazy.
I am java developer but never came across ant or maven before.
I want to know what exactly happens with the dependency tag in POM.xml file?
Lets say, I am using camel framework and want to use camel core jars.
If one of my class file contains following line:
CamelContext context = new DefaultCamelContext();
so what exactly I need to do after that?
Do I need to include the jars myself in the class path or dependency tag will download the jar files over internet for me?
If the case is former, what dependency tag will do? & where should I place my jar files? I mean is there any specific location on my hard drive? and
if the case is lateral then during compile time I get error "cannot be resolved to a type"
And the imports are to be specified or not?
I know the question might sound silly but I am not able to find its answer.
I have tried googling alot, it didn't help me still.
Any help would be greatful, even help on maven topics which I might come across in near future would be appreciated.
Thanks in advance.
Solved. Please check https://stackoverflow.com/a/20094312/1121208 for help
dependency tag will download the jar specified in the dependency tag for you if available. Otherwise will raise a pom.xml error - could not found dependency..
Imports have nothing to do with maven. They will appear when you will you another class in your class/java file. So if you import in build path the jar by yourserf or if you put it there with maven, you will have the import.
Are you using eclipse or any other ide ?
First of all, Maven is a build tool. It doesn't run your app. It builds it. So, at runtime, the classpath needs to be set like for any oter application yo would have built with something else.
When you build an app, you depend on external libraries. The dependencies mechanism of Maven simply lets you declare wwhich libraries your ap needs. When you build your app, Maven downloads these libraries from a central repository (or sevaral ones), and stores them in a local repository on your hard drive. These jars are automatically added to the build classpath by Maven. At runtime though, depending on the kind of ap you're building, you'll have to copy or embed those jars in order to create a runnable application.
The rules of Java don't change just you build them with Maven. Meven uses the stadard Java compiler (javac). And of course, if you want to use a class by its simple name, you'll have to add an import statement for this class.
I think that, before using Maven, you should try to compile and run a simple application depending on an external library without using any IDE. You would then understand better all the steps that are required to build and run an app, the concept of build and runtime classpath, etc.
Finally got what I needed to know
Sharing it for others who may stuck up in same situation
Does dependency tag download the jar specified?
maven dependency tag actually downloads the jar files you specify in the dependency tag. It downloads and save it under .m2/repositories(local repository) folder on your hard drive (along with some information like last updated, etc)
Local repository is shared among all your projects
from where it downloads?
It downloads the jar from the central repositories. There central repositories contain almost all the open source jar files one needs in a project. It downloads based on information you provide in groupid, artifactid, etc.
http://repo1.maven.org/maven/
http://mvnrepository.com/
can be checked for correct groupid, etc
Once these jar files are downloaded, they are automatically added to the classpath and are available in your project for use.
If the jar files you are searching for, are not available in the central repository, maven may throw error, in that case you can download it manually and let maven know about it.
Without maven you need to put jars into lib folder.
With maven you specify as declaration inside <dependencies>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.17</version>
</dependency>
and when you do mvn package, maven will download required jars on your PC.
With Eclipse and m2e (maven eclipse integration) you can do that all not leaving Eclipse,
and even get sources for used libraries automatically.
Read http://maven.apache.org/ It worth it.
I want to add google analytics package/jar to a scala project with SBT. However I cannot find the URL of the project on http://mvnrepository.com/
I've also tried looking for it on google forums but to no avail.
I'm thinking of downloading the jar and adding it to sbt as an unmanaged jar. I think a jar is found at https://code.google.com/p/google-api-java-client/source/browse/com/google/apis/google-api-services-analytics/v3-1.3.3-beta?repo=mavenrepo&r=5f31c0ad06088b1762f414890cef93ba177ad4b8
but this is a maven repository. Now, instead of downloading the jar, I'd like to let SBT handle downloading of libs, but for this I need the URL of the maven repository that I just posted the link to where the google code is.
Question
Is there a way to figure out the URL to the maven repository where google analytics jar is stored (from the URL above)? Any other repository that has a copy of google analytics will also do.
I think this is what you want: http://mvnrepository.com/artifact/com.google.apis/google-api-services-analytics
In this case I just googled the artifact name ("google-api-services-analytics") but the structure of maven repositories tends to be very predictable. If you go one level up in the google code page you linked and check out maven-metadata.xml, that will tell you the group and artifact to look for in a repository.
I have moved to Maven recently, and since it works fine for resources up to date in some repositories, it's not obvious for non-maven ones.
I have something very simple to achieve (in the idea), but that I am unable to express so far:
I need to compile my code with a jar that can be found here:
https://hudson.eclipse.org/hudson/view/WTP/job/cbi-wtp-wst.xsl.psychopath/ws/sourceediting/plugins/org.eclipse.wst.xml.xpath2.processor/target/
What do I have to put in my pom.xml to make Maven downloading the .jar + the java source + the javadoc, and eventually the other dependencies (actually IBM ICU, Xerces, JavaCup) that are mentionned in the supplied MANIFEST ?
I have read lots of documents, including those with a plugin called Tycho, but nothing helpfull for that simple task.
Thanks for your help.
Maven only works well if all artifacts needed for a build are contained in the local or a configured remote repository. So you have to do the following jobs:
Find out if eclipse plugins are deployed in a Maven2-style repository, and what the URL of that repository is.
Then find out which version of that plugin (artifact) you need.
Maven allows you to configure what will be copied locally: jar file, sources and api doc if you want to.
Maven should then be responsible to download as well all needed artifacts for the plugin you want to use.
After looking at the contents of the URL you gave us (especially the file p2content.xml), it looks like there should be a repository. I searched for the maven repository for org.eclipse.wst.xml.xpath2 and found the URL http://maven.eclipse.org/nexus/content/repositories/testing/org/eclipse/wst/org.eclipse.wst.xml.xpath2/1.1.0/org.eclipse.wst.xml.xpath2-1.1.0.pom
So the repository you are searching for is located at http://maven.eclipse.org/nexus. Just open it, search for example for xpath2, and Nexus, the repository software used there will you show the available artifacts. Depending on what was deployed to that repository, it may contain only the library, or have even sources and JavaDoc bundled with it. For the example above (xpath2), there seems to be only the POM itself and the library (the jar). If you take as example junit, you will find all versions and variants, even with sources.jar and javadoc.jar.
After you have found the needed artifact, you can include it in the dependency section of your POM. And you have to add http://maven.eclipse.org/nexus as a remote repository in the configuration of your Maven installation.
The question and its answer Get source JARs from Maven repository explain how to fetch sources and JavaDoc (if they are available).
You need a maven repository which contains this artifacts (i don't know, if Eclipse hosts a repository for their projects). You can also deploy manually the artifacts to a local repository on your computer.
Is it possible to specify sources and/or javadocs to be included in dependency JAR's with the Play Framework?
I want to be able to browse the source and javadocs for 3rd party libraries in Eclipse. The Maven Eclipse plugin can apparently be configured to provide this functionality as seen here, I'm wondering if Play provides similar facilities as well.
Have you looked at the Maven plugin? http://www.playframework.org/modules/maven
It explicitly mentions source and javadocs in its description.
Expected behavior this module:
Allow declaration dependencies in pom.xml, without putting
explicitly unless the transitive dependency does not work (for older
version or depending on undesirable big jar file)
Able to download all dependencies not provided by Play into lib
folder, with src and javadoc
Able to download source/javadoc artifiacts to depsrc folder for
declared or transitive dependency which is provided by Play, for
easier debugging (using command mvn:play-src)