I've googled on it and I've seen a lot of different sites that offers the struts2-junit-plugin.
I'm currently using struts-2.2.1.1. Should I get struts2-junit-plugin-2.2.1.1 as well?
Also, my project doesn't use Maven. When I downloaded a struts2-junit-plugin, I inspected the .jar file and found a pom.xml containing all of its dependencies. Should I separately download all these dependencies manually since I don't use Maven?
Yes, you should use the matching junit-plugin version (2.2.1.1)
Yes, but you also need to load the dependencies' dependencies, the dependencies' dependencies' dependencies ad nauseam until you're at the end.
Point 2 is why you really should be using Maven or similar mechanism.
Getting dependencies by hand is error-prone, tedious, and silly.
Related
I'm working on upgrading a legacy Java project to be compatible with jboss wildfly. As part of that process, I'm replacing our old system of managing dependencies (manually scanning for jars in a folder) with an automated system.
My first thought was to use maven, which worked well initially. The maven plugin for eclipse was able to scan my project and create a pom with most of the required dependencies. That works fine for compiling and running with eclipse, but production deployment uses an ant build script. I looked into maven-ant-resolver ( https://maven.apache.org/resolver-ant-tasks/index.html ) but as far as I can tell that project doesn't have a way to add dependencies to the classpath, the best it can do is bundle them into a jar.
The other option I looked at was Ivy. It seems better suited to integration with ant. Unfortunately, the tooling for ivy seems primitive compared to maven. From what I can tell, there is no option to generate the dependency file (ivy.xml) from an existing project. With the number of dependencies I'm dealing with, especially from jboss, creating the dependency xml from scratch is not a realistic option.
What are my options for solving this problem? Is there a way to do what I want with maven or ivy that I'm not seeing? Is there another dependency management tool out there that offers all the features I need?
The maven-assembly-pluginis what i can recommend for likely usecases. Not sure if it suits you though.
In a nutshell:
You can pack folders, jars, resources, dependencies, whatever into a jar for production deployment. This jar is packaged with the, from maven-assembly-plugin internally used and thus not needed to be referenced explicitly, maven-archiver-plugin which also stores a MANIFEST.MF with the classpath in it (not by default but with few codes of tweaking).
Useful to know though: Maven allows you to quite easily create own Plugins that completely do what you want. If its just a file with the stored classpath, this could be a clean solution.
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'm converting an existing project structure to Maven where there's EJBs and JARs contained in EARs that are deployed. My issue is with making EARs. It seems obvious to use the Maven EAR plugin, which either takes an existing application.xml or generates one on basis of configuration.modules. I feel I'm not entirely leveraging Maven if I would not use the modules configuration (although it would allow developers to reuse the existing application.xml editor), but I'm thinking about many of our developers who love to click around in RAD/Eclipse to get things configured. So I took a look at RAD/Eclipse in full expectation to see some m2e support that would allow me to point-and-pick my EAR modules, and then see the modules in the POM file being populated accordingly. But I'm not able to find such thing. I believe I installed m2e (1.3.0) and m2e-wtp (0.17.0) although it seems to bring me very little in terms of WTP/EAR support. Also I spent most of tonight googling around, to no avail. Should I forget about it and have devs just manually edit the POM file, or am I overlooking some nifty UI for this purpose? Thanks for your pointers!
Seeing a comment and an answer that drive me to elaborate. I do appreciate that when using Maven, Maven is leading. No argument there. And I know that I can take control over the application.xml back using generateApplicationXml, but that's not even what I'm after, again Maven can be leading. But as I can use the "Maven POM Editor" to edit the basic structure of the POM, would there be any UI available to edit the configuration.modules? Our devs are very acustomed to IDE-centric development, and them having to start editing POM file XML in order to manage modules is something that scares me slightly...
If you want to configure your application.xml manually you can include the file to your source folder and set the generateApplicationXml property to false so maven will not overwrite it.
See for details: http://maven.apache.org/plugins/maven-ear-plugin/generate-application-xml-mojo.html#generateApplicationXml
I have inherited a big project with several subprojects.
all of them use several jar files, all of them located under each project's lib directory. I want to take all the projects and migrate them to maven, but dependencies are a problem (too many of them), some of them are commonly used libraries (apache projects, xerces, jms, etc) and others are not.
is there a way to autogenerate maven dependencies for those jars that can be found on public maven repositories. for example, see that my project use the spice-jndikit-1.2.jar file and automatically get the appropiate depedency with group, artifact and (if possible) version?
thank you
I wrote a groovy script to generate a starting set of Apache ivy files.
https://github.com/myspotontheweb/ant2ivy
In my case, I wanted to "Maven-ize" my ANT builds without switching completely away from ANT.
It is feasible to extend this code to generate a Maven POM, if people were interested in this feature.
You can convert a project to Maven using the m2e plugin, but this erases your jar references, and should not be used.
I doubt that such a thing exists since typical jars (unless themselves built with Maven) don't have the necessary information to correlate the groupId, artifactId and version back to a repository to get the proper path.
You might be able to write something that parses the file name for the name and version, but you still have the package-based path to figure out.
If you're building using Ant, you might also consider using Apache Ivy, and its file-system based resolution (very fast and easy to configure), to get you started, and slowly role over to the Maven repos for the artifacts, this way you're not spending a lot of time up-front finding Maven dependencies.
I have a library that I wrote in Scala that uses Bouncy Castle and has a whole bunch of dependencies. When I roll a jar, I can either roll a "fat" jar that has all the dependencies (including scala), which weighs in around 19 MB, or I can roll a skinny jar, which doesn't have dependencies, but is only a few hundred KB.
The problem is that I need to include the Bouncy Castle classes/jar with my library, because if its not on the classpath at runtime, all kinds of exceptions get thrown.
So, I think the ideal situation is if there is some way that I can get either Maven or SBT to include some but not all dependencies in the jar that gets rolled. Some dependencies are needed at compile-time, but not at run time, such as the Scala standard libraries. Is there some way to get that to happen?
Thanks!
I would try out the sbt proguard plugin from https://github.com/nuttycom/sbt-proguard-plugin . It should be able to weed out the classes that are not in use.
If it is sufficient to explicitly define which dependencies should be added (one the artifact-level, i.e., single JARs), you can define an assembly (in case of a single project) or an additional assembly project (in case of a multi-module project). Assembly descriptors can explicitly exclude/include artifacts from the dependencies.
Here is some good documentation on this topic (section 8.5.4), here is the official documentation.
Note that you can include all artifacts that belong to one group by using the wildcard notation in dependecySets, e.g. hibernate:*:jar would include all JAR files belonging to the hibernate group.
Covering maven...
Because you declare your project to be dependent upon bouncy castle in your maven pom, anybody using maven to depend upon your library will by default pull in bouncy castle as a transitive dependency.
You should set the appropriate scope on your dependencies, e.g. compile for stuff needed at compile and runtime, test for dependencies only needed in testing and provided for stuff you expect to be provided by the environment.
Whether your library's dependencies are packaged into dependent projects when they are built is a question of how those are projects configured and setting the scopes will influence the default behaviour.
For example, jar type packaging by default does not include dependencies, whereas war will include those in compile scope (but not test or provided). The design aim here was to have packaging plugins behave in the most commonly required way without needing configuration, but of course packaging plugins in maven can be configured to have different behaviour if needed. The plugins themselves which do packaging are well documented at the apache maven site.
If users of your library are unlikely to be using maven to build their projects, an option is to use the shade plugin which will allow you to produce an "uber-jar" which contains all the dependencies you wish. You can configure particular includes or excludes.
This can be a problematic way to deliver, for example where your library includes dependencies which version clash with the direct dependencies of projects using it, i.e. they use a different version of the same libraries yours does.
However if you can it is best that you leave this to maven to manage so that projects using your library can decide whether they want your dependencies or to specify particular versions giving them more flexibility. This is the idiomatic approach.
For more information on dependencies and scopes in maven, see the reference guide published by Sonatype.
I'm not a scala guy, but I have played around with assembling stuff in Java + Maven.
Have you tried looking into creating your own assembly descriptor for the assembly plugin? https://maven.apache.org/plugins/maven-assembly-plugin/assembly.html
You can copy / paste the jar-with-dependencies descriptor then just add some excludes to your < dependencySet >. I'm not a Maven expert, but you should be able to configure it so different profiles kick off different assembly builds.
EDIT: Ack, didn't see my HTML got hidden