How to deal with Maven projects containing several internal artifacts? - eclipse

I'm about to start working on a web-application and I'll be using Maven. I want the web-application to be an individual artifact. The web-application will end up depending on a couple of self written libraries (for example text-formatting), and each of these libraries should be an individual artifact.
What's the recommended way of achieving this separation while making it simple to code for both artifacts? I was thinking of creating one project for each artifact and import them one by one in Eclipse. However, if the pom for web-application has a dependency pointing at the self written library, I'll end up having to deploy a snapshot every time I want to see if the change I made stopped the web-application from crashing (in example).
I hope you understand what I am getting at. I'll be working with a couple more developers, and we're using Nexus to maintain our shared artifact repository.

I was thinking of creating one project for each artifact and import them one by one in Eclipse.
Yes, that's the recommended way.
However, if the pom for web-application has a dependency pointing at the self written library, I'll end up having to deploy a snapshot every time I want to see if the change I made stopped the web-application from crashing
During development, you can use "workspace resolution" i.e. configure Eclipse to resolve dependencies from the workspace. This way changes are immediately visible from the webapp. This is possible whether you are using m2eclipse or the maven eclipse plugin (and is actually the default behavior for both).
Below, an illustration for m2eclipse:

A good maven plugin for eclipse is capable of "workspace resolution", i.e. it will recognize if the dependency is also present in the workspace, and refer to the other project directly rather than adding a JAR to the build path.

Related

Import multi module project in Eclipse

I am trying to get started with Eclipse SCADA and import the projects from their git repository.
I have cloned the following projects:
org.eclipse.scada.external
org.eclipse.scada.utils
org.eclipse.scada.base
org.eclipse.scada.protocols
org.eclipse.scada.core
org.eclipse.scada.releng
For each project I did mvn verify in the parent folder and imported the projects in Eclipse. I also changed target platform. However, I still seem to have problems with their dependencies.
Any help would really be appreciated.
Actually the Eclipse SCADA java projects are not developed with "Maven first". So you should disregard maven completely while in the IDE. The maven build is basically only used to build the project unattended.
The issue with the target platform is more complex. We were a bit sloppy in providing a always working target platform (and it is actually difficult to keep them up to date, since the versions of the bundles are fix).
I made a target platform file for the current version, you can find it here: https://gist.github.com/CptMauli/ec6eda37734f0108510f
To make it work properly please download a classic eclipse put it somewhere and create an environment variable ECLIPSE_432_HOME which points to it. Alternatively you can just change the first entry in the target file and point it directly to it.
The reason behind it is, if you would use your own eclipse installation, it is possible that bundles installed there conflict with bundles provided in the target platform or from your workspace. This is actually mostly not even a problem when compiling, but as soon as you start a client or a server, Eclipse will complain about duplicated bundles.
If you have any more questions please go to our mailing list: https://dev.eclipse.org/mailman/listinfo/scada-dev
or our google group: https://groups.google.com/forum/#!forum/openscada
or write to me directly at juergen dot rose at ibh-systems dot com

How to Create a Spring+Primefaces+Hibernate (no maven) project in eclipse?

I am new to J2EE. I would like to create a Spring+Primefaces+Hibernate project.
I googled for it.
But I found all projects examples show in internet contains maven. My questions are
Is it possible to create a spring+primefaces+hibernate project in eclipse without Maven? If no, what is need of maven?
How to add the jar file of primefaces and spring and hibernate in eclipse?
Will the spring controller xml file (spring context or dispatcher servlet) be created automatically or manually?I mean Spring MVC.
Will the hibernate file (mapping file) also be created automatically or manually?
If possible, can anyone guide me to tutorial (preferably video) to implement the same?
I am using tomcat 7 and Eclipse - kepler.
Any help is appreciated.
If this is downvoted , do specify the reason also.
Although it's not a 'must' to use Maven or any other build tool, you should strongly consider using one.Eclipse Kepler has by default maven support but feel free to use other build tools(Gradle, Ant) or none(see 2.).Maven and the other build tools remove the headache of scaffolding, searching for dependencies(external jars like spring-mvc, hibernate, some db drivers), even deploying applications in a server.
If you chose not to use a build tool you have to manually get your project dependencies and enter them
into your project's buildpath(Right Click -> Build Path then enter their location).As you have noticed this step can be really really time consuming...
No, you have to manually create the configuration unless you use another project that already has what you need, again this might get easier with a build tool(maven archetypes for example)
The same as 3.
You won't have a hard time finding resources about these technologies, they are being used practically everywhere, and I think the Spring team has some videos in their YouTube channel.
Hope that helps a little!
1:* The fundamental difference between Maven and Ant is that Maven's design regards all projects as having a certain structure and a set of supported task work-flows (e.g., getting resources from source control, compiling the project, unit testing, etc.). While most software projects in effect support these operations and actually do have a well-defined structure, Maven requires that this structure and the operation implementation details be defined in the POM file. Thus, Maven relies on a convention on how to define projects and on the list of work-flows that are generally supported in all projects.
This design constraint resembles the way that an IDE handles a project, and it provides many benefits, such as a succinct project definition, and the possibility of automatic integration of a Maven project with other development tools such as IDEs, build servers, etc.
But one drawback to this approach is that Maven requires a user to first understand what a project is from the Maven point of view, and how Maven works with projects, because what happens when one executes a phase in Maven is not immediately obvious just from examining the Maven project file. In many cases, this required structure is also a significant hurdle in migrating a mature project to Maven, because it is usually hard to adapt from other approaches.
In Ant, projects do not really exist from the tool's technical perspective. Ant works with XML build scripts defined in one or more files. It processes targets from these files and each target executes tasks. Each task performs a technical operation such as running a compiler or copying files around. Targets are executed primarily in the order given by their defined dependency on other targets. Thus, Ant is a tool that chains together targets and executes them based on inter-dependencies and other Boolean conditions.
The benefits provided by Ant are also numerous. It has an XML language optimized for clearer definition of what each task does and on what it depends. Also, all the information about what will be executed by an Ant target can be found in the Ant script.
A developer not familiar with Ant would normally be able to determine what a simple Ant script does just by examining the script. This is not usually true for Maven.
However, even an experienced developer who is new to a project using Ant cannot infer what the higher level structure of an Ant script is and what it does without examining the script in detail. Depending on the script's complexity, this can quickly become a daunting challenge. With Maven, a developer who previously worked with other Maven projects can quickly examine the structure of a never-before-seen Maven project and execute the standard Maven work-flows against it while already knowing what to expect as an outcome.
It is possible to use Ant scripts that are defined and behave in a uniform manner for all projects in a working group or an organization. However, when the number and complexity of projects rises, it is also very easy to stray from the initially desired uniformity. With Maven this is less of a problem because the tool always imposes a certain way of doing thi
2:* You have to download all required jars file for hibernate/spring/primefaces from internet and place them in your project build path or in lib folder.
3:* Spring configuration files need to be created by you so that you can get the concept.
4:* Hibernate mapping files can be created by using reverse Engineering techniques for hibernate from where you can generates hbm files or you can use annotations if you dont want xml.
I suggest you to first create a sample java project in eclipse then download all required jars and place them in lib folder. Then configure hibernate in projects and spring integration.

Dynamic web application in eclipse using MAVEN 3.04

From past 90 hours I am trying to know how to use Maven in my web project, generate a war file and deploy it into my JBoss 4.2 Server.
I am not getting.
I am reading all kinds of blogs, googling almost all time, trying out all kinds of way to build a dynamic web project with maven, but trying out different methods make a simple thing more complex.
Few examples tell me how to run, few tell me to change the folder structure, few tell me transfer the contents of web content but nothing is matching my requirements. In some of the examples war file is getting generated, but of some big name, and it does not contain the jars inside. Uff.
I know maven is easy and makes our lives better but learning it for the first time makes it complex.
My requirement is simple.
1) Build a Dynamic web project in eclipse indigo. (Preferably in JAVA perspective )
2) Enable Maven dependencies, in eclipse.
3) Update pom.xml to add dependencies.
4) Finish the web application i want to do by writing classes, html pages, deployment descriptors.
5) Build the war file using maven "IN ECLIPSE ONLY". (the WAR file must have user specific name and not some name like "V1- Snapshot dash dash dash")
6) Deploy my war file in jboss 4.2 server deployment location. (Preferably from eclipse )
7) Run my localhost server and my application from the browser.
And Done.
By spending time on it I am understanding how beautiful is maven, but I am not able to achieve what I want.
Please help me by giving me a detailed procedure on how to use maven to meet my requirements above.
Fist I would suggest to use the newest Eclipse (Juno) with Maven support (m2e and wtp-m2e).
The first step is to define your pom with the appropriate dependencies and the correct packaging type which is in your case war.
If you really need a different naming you should leave Maven, cause maven makes assumptions about the naming of your artifacts which usually isn't a problem. The default version patterns as 1.0.0-SNAPSHOT etc.
If you wan't to deploy the war into JBoss there exist a number of possibilites to do such things and if you like to run your application locally it sounds you wan't to do some kind of testing (integration testing) which is supported by Maven (see maven-failsafe-plugin).
Furthermore you must learn if you like to use Maven to understand that not Eclipse is anymore the leader of the project configuration. This job has been moved to Maven or in other words into the pom file. If you like to use the project in Eclipse you need to import this project into Eclipse.
Apart from the above i would suggest to go to a Maven training to lear all that stuff which is more effective than learning it yourself.

Keeping Eclipse project dependencies in sync with an external build system

Here is the situation. A development team has a large number (hundreds) of Eclipse projects. The code is very much in churn - new projects are being created; projects are being renamed and project dependencies are constantly changing. The external build system is ant. It is proving extremely challenging to keep the dependencies defined in the ant build files in sync with the state of the world in Eclipse. The external ant build needs constant changes to keep up. For various reasons, using ant as the default builder in Eclipse is not an option. The developers want to continue using Eclipse as the build and edit environment for local use.
Question: Is there a tool which will allow a single set of dependencies to be maintained which can be used by Eclipse as well as an external build system like ant?
I have heard of Gradle but never used it before. Would it make sense in this context? I am pretty sure Maven wouldnt work for what is needed
The typical workflow should be:
1. Developers continue working as they currently do - creating and changing Eclipse project dependencies at will and using the default Eclipse builder to compile and test locally.
2. Some mechanism exists by which these dependencies can be carried into an external build system like ant and an external continuous build triggered on every checkin.
Appreciate your feedback - thanks!
We have been quite successful at using Gradle to tackle a similar problem. Here's the outline of the setup
Each project contains a build.gradle that defines project specific dependencies and tasks (may even be empty).
A special master project contains build.gradle that sets up common dependencies and tasks for child projects, and/or injects settings pertinent to a group of child projects.
Logically master project is the parent project, but it exists as a sibling folder so that Eclipse can be more comfortable with it.
Gradle contains a built-in Eclipse plugin which allows generation of Eclipse settings files for each of the projects from the dependencies information (including inter-project dependencies). It works nicely for simple projects, and as for more complicated ones Gradle allows you to tinker with the settings files, so you can do pretty much everything. From here you have two options:
Not to store Eclipse settings file in the repository and call the generation task every time you do a fresh check-out (I prefer this option).
Tell Gradle to use custom variables to make it generate generic settings files which can be checked-in to the repository. You'll then only need to run the generation task when dependencies or other configuration changes.
(Optional) It's a little tricky, but you can make Gradle parse existing project ivy.xml files and set up dependencies from there. I had some success with this, although I would recommend converting dependencies into Gradle format for more flexibility.
Continuous build system integrate with Gradle very well (same as ant). If you are using Jenkins (Hudson) there is a Gradle plugin.
The advantage of using Gradle is that it scales pretty well, and you can support other IDEs like IntelliJ or Netbeans at the same time without much effort (unless you have lots of crazy custom settings). An advantage and a disadvantage is that Gradle is a powerful build system which requires learning Groovy and Gradle DSL which may take some time to acquire. Also the documentation is awesome.
Gradle has a very active community with the sole purpose of tackling exactly this kind of problem.
Hope this helps, and best of luck!
How about parsing the .classpath files, generate a dependency tree and start building from the root. What you need is a convention on the layout of your projects or an generic (ant-) buildfile that could be changed in each project, if needed (e.g. different project layouts). I´m not sure if Eclipse Tycho could be used for that, since it´s a maven plugin(s) to build eclipse plugins or projects. But it´s able to resolve the bundle and project dependencies against maven repositories and eclipse update sites.

Set up an Eclipse Dynamic Web Project referencing another project

I've got a simple Dynamic Web project set up in Eclipse 3.6 Helios, but am having trouble getting it to make use of the code in another project that I've got.
I've added a reference to my other project to the build path of my web project, and I've got no problems in terms of compiling, only in terms of deploying and testing the result. The built web application doesn't have a jar in the WEB-INF/lib directory, so fair enough it can't find the code. The question is how I set this up. I've looked through the help that I can find and googled a bit but can't find anything obvious that helps out.
How do I set up my web project so that on deploying it it magically has the code from my dependent project inside it?
Thanks.
Note: Ideally I'd like a solution that doesn't involve setting up some kind of build tool. The web project deploys itself without recourse to any build tool (or at least none visible to end user), so was rather hoping that a references project could be integrated into that easily.
What goes in the deployment is determined not by the build path but by the Deployment Assembly entry in Preferences for the dynamic web project.
Use some build tool like ANT or Ivy or Maven that, on build, copies all the dependencies to WEB-INF/lib
Using a build tool is a good practice to automate build, test and deployment. You may also be interested in plug-ins like Maven Reactor.