I have a project that devided into three pieces, PCommon, PWebapp and PAdminConsole. PWebapp and PAdminConsole are dynamic web project in eclipse, PCommon is java project, and both two web project will use the api in PCommon as a jar file in lib folder.
In the past,I added import project in build path, I used Ant to compile and build PWebapp and PAdminConsole and in both build.xml file there is
<ant antfile="${common}/../build.xml" inheritAll="false"></ant>
to make PCommon into a jar file.
Now I will change all my projects to Maven Project. But I don't know how to make two web projects contain one public module, and how to package my PCommon into a jar file automaticlly when I run package maven command to package one web project.
Now I always deploy my PCommon.jar on nexus server. and then add dependcy in pom.xml in web projects. But I think there is no sense to deploy the jar on the public server, so I think it isn't the right way to archieve this goal. Is there any way that is more convenient?
I know I can make a parent project with a parent pom.xml. But I have two web project need the module, the pom.xml in PCommon can only extends one parent, can't it?
The common way to resolve dependencies in Maven is using a repository. The first time a dependency is needed, it is downloaded from your repository and installed in the repository on your local machine. If a dependency is not available in the remote repository it has to be installed to your local one in some other way. There are a few other ways to resolve depenencies without using the repositories but I wouldn't suggest to use the.
To make this a little more convenient, you can use a proper IDE. I use Eclipse with the m2e plugin. It supports something called "workspace resolution", which should be enabled by default. It scans your workspace for other Maven projects before falling back to the repository lookup. This has the advantage that every change you make in your common project is immediatly available in the other projects. I think it also gets installed to your local repository in the background but I'm not sure. Anyway you don't have to worry about it yourself.
Something similar works with IntelliJ IDEA but I don't have that much experience with it. I'm sure Netbeans has some kind of Maven support too.
Related
I'm trying to add Maven to already existing java project. It's been quite an adventure. I've read many questions here but I don't quite get it. The app I'm building is kinda modular so I'm loading many classes from URL so that the need of replacing the .exe (wrapped jar) file is at its minimum (Cuz once opened by any user I'cant update - replace the app (.exe)).
Since I'm using wide variety of libraries and the app Jar, hense the .exe, became too large - ~80MB, and slow to open from fileshare. Hense the need of Maven (or so I think). Since I installed Maven I had to add package statement at the top of every class, because before then there was not such thing, nor the need for it. Maven found the dependencies online and for the most part the process was not so time consuming, but the goal is to load the libraries from the project(app) folder /lib/. There I have all the libraries in jar files that I need. My question is: Is there a need of installing the libraries to local m2 directory (as I've read) since the app should always load them from the app folder? How do I configure the POM so the project/lib/ directory is recognized as a repo (or even is this the right approach), and load the libraries from the relative path of the project folder?
Thanks in advance to anyone able and willing to help!
Maven's core objective is to manage dependencies. You can add a dependency to your project, by configuring it in pom.xml, maven will download the dependency from the maven central repository & when building the project, maven can help you create a runnable JAR that have all your dependencies & code compiled.
Let's say in your current project if all of the dependencies are absolutely necessary, then even after migrating the project to maven, you're runnable JAR will remain the same size. There won't be any reduction in your application size. However, I would highly recommend migrating your project to any build tool like gradle or maven to manage project dependencies.
I have a project based on Spring which is running successfully. Now I have created another project based on Jersey which I want to integrate with spring project in Jersey.
I have gone through internet and I added spring project in the build-path of the Jersey project.
Here the problem is whenever I run my Jersey project, it has to execute the Spring project first.
How to configure spring project in Jersey?
You should consider using a dependency management/build tool such as Maven or Gradle.
This way each of your projects will be a module, which can be referenced from the other project as a dependency. You can still use the first project alone and the two-dependent projects alone as wall. Then the tool lets you just simply package the resulting project in a artifact such as WAR with all the dependencies.
Here is a quick maven tutorial - Maven in 5 Minutes
It is a good idea to use such a tool in any case as it has many additional advantages:
Lets you manage also your third party dependencies without needing to manually download the libraries and add them to the classpath
It is much easier to use such a project in cases like continuous integration.
You can run all your tests automatically during the build process to make sure everything works
It resolves transitive dependencies (dependencies of your dependencies)
It builds resulting archive file for you
You can have multiple profiles for different environments
...
Make both of your projects modules of one Maven parent pom project. This way you can build them both at the same time.
I'm using eclipse with the m2eclipse plugin now I just want to resolve a - imho - easy problem: I've got two maven projects, I want to add project A as dependency to project B.
Well how do I achieve this in a manner way? If I add the project A to the build path of project B eclipse recognizes the classes but this project isn't resolved by eclipse on build time.
I got it working by installing project A to my local repo and adding this as dependency to my pom. This works but is cumbersome because I always have to install a new version of project A when something changed.
Shouldn't the plugin handle such a situation for me?
Providing that you have both maven projects open in your workbench then make sure you have the "Enable Workspace Resolution" option enabled in the Maven context menu.
Yes Eclipse handle this situations.
You can add both the Projects A and B in the same work-space.
I could help you creating a simple work-space from the scratch.
I am assuming that you have already installed the MAVEN plugin M2Eclipse for Eclipse.
Start a new Eclipse in a blank Work-space
Right click on Project Explorer --> Go to Import dialog and add a Maven Module.
Locate the POM directory and add that directory.
It will list all the projects in all the sub folders.
Add as many as Maven Based modules in a single work-space.
By doing this you dont need to install the dependencies. Any change will be reflected on the derived module.
Hope that will help you.
The way you did it is correct, because it assumes that project B will be using the dependency of project A that will be in the artifactory, so you can develop both independently.
And anyway, for the project A, if you are using maven, don't you use maven clean install for compiling and deploying? That way you are sure you always have the latest version
The other option is, in case both of the are more dependent of each other, you should consider make one of them as a module of the other, or maybe make a project C that contains both modules, but that would mean both of them are part of the same project (like an ear containing two jars), depends on the situation
I've been asked to apply Maven to a project. After browsing a dozen sites it appears that it's quite vast and I'm not familiar as I'd like with similar tools like Ant. Why is it used/preferred and what does it offer over a standard Eclipse project? Also, how could it be added to an existing project?
Why is it used/preferred and what does
it offer over a standard Eclipse
project?
It is a build tool which can build your project without the need for an IDE like Eclipse. It can create a jar or war or other artifacts from the source, performing a bunch of steps like compilation, running unit tests, etc.
Where maven scores over ant is in managing third-party dependencies and in convention over configuration (which mean less lines of build script if you follow convention).
Also, how could it be added to an
existing project?
You start by creating a new maven project, following the step here.
Place it in the root folder of your project
If your source and resource files do not follow maven folder convention, update maven properties suitably referring to this documentation.
Run mvn package
It will fail if it needs any third party dependencies, which you can add as specified in the doc
With some trial and error, you should have your project running with maven, possibly, much quicker than if you were to set up the same with ant.
Others are already provided sufficient resources to read more about maven.
I suggest to start reading here:
http://www.sonatype.com/books/mvnref-book/reference/public-book.html
Maven is a great tool when you know how to use it. Maven (at core) is a dependency manager.
You include in your pom.xml (similar in function to the build.xml from Ant) all the librairies your project depends on (example : apache commons) along with their version and Maven get them directly from a repository (by default, the central maven repository)
Then you do not have to manually install any jar to make your project work. All is downloaded and cached on your local machine. You can even create an enterprise repository where you put all the jars needed by your company
Maven uses the concept of artifacts which are pre-built library projects with their own dependencies
To mavenize a project, you'll have to write a pom.xml describing your project (examples are numerous), get rid of your libs directory (or whatever classpath you described under Eclipse) and add all your dependencies to your pom.xml
You could also check Mavenizer for a first-start
But Maven is a lot more what i've just said. Read the docs, read poms from librairies and you'll get used to it quickly ;-)
If you use the M2Eclipse plugin from Sonatype, it's just a matter of right clicking the project in the package explorer and choosing Enable Dependency Management in the Maven menu. You are also advised to adjust the directories that contain the sources to the Maven standard directory layout but if you absolutely can't, you can configure that later.
Apart from that: Well, look for tutorials and documentation (for example there is the free book Better builds with Maven. Maven is very complex (yes, I don't think it is simple) and very powerful.
I have a java project that is composed of 3 sub projects that generate a .jar artifact each (and have sub-dependencies among them).
In addition there is a web projects that depends on the first 3 projects and generate a war file. The war file is my final artifact, i.e. what I ship my customers.
Additionally I have a parent module that encompasses all the other projects:
<modules>
<module>../core</module>
<module>../commons</module>
<module>../api</module>
<module>../web</module>
</modules>
I generate eclipse files (mvn eclipse:eclipse) and work with eclipse. The problem is if I modify one of the non-web projects I must manually install it before deploying the web project to my web container. How can I make that the web project depends directly on the source code of the others and not on the version installed in the repository.
In your web application properties (right clic on the project in the Package explorer, then "properties"), add the three modules (core, commons and api) in the "J2EE Module Dependencies" (the others modules must be opened in the Eclipse workspace).
Do you want to add a dependency on the source jars deployed to the repository?
If so you can do it by adding the sources classifier to the dependency. See this answer for more details.
If not, can you clarify further please.
I think your problem is that you are just building just the war project. If you are building it from the command line, then what you have to build is the parent module. "mvn package" in the directory that contains the parent module should be enough. Of course this means that you have to build all the packages every time, but that is the way maven works.
The dependency:tree goal by itself will look things up in the repository rather than the reactor. You can work around this by mvn installing, as previously suggested, or doing something less onerous that invokes the reactor, such as
mvn compile dependency:tree
Works for me.
Edit: D'oh! Posted this answer to the wrong question. Was meant to be answering this