I want that a maven project can be used as a black box jar. This is needed because second project was born its way, and I don't want to integrate its code by hand. So the best way is that this project is going to save it's data on db, but it should use a service offered by the "wrapper" project to save them.
The idea is simple, the secondary project can expose just a method to which I will pass the service that offers the save method as a parameter.
The secondary project should not have configuration files, but should rely on the father application's properties.
Any idea to do this fast and almsot good? Thanks for any suggestion.
EDIT 2013/03/07: The idea behind this is that the second project should generate a classic jar library that looks a properties file into the classpath of the host project. Something like Quartz/Spring/... you import jar and you provide the properties file.
I just defined some classes to load properties from the classpath, and some interfaces to make the two projects interact.
In pom.xml of the parent project I imported the child project excluding it's dependencies to avoid conflicts.
It was a pretty easy task at the end.
Related
We have a EAR project which has a WAR project. Maven is used, so pom.xml. As typical of any project, this project also contains a big feature (say Job Scheduling "JBS") among many other features. As it is planned to retire this whole project in the near future, it is discouraged heavily to spend much on working on this project (whether bugs or enhancements).
Therefore, for the sake of running the (JBS) feature as a separate application, the whole EAR project was duplicated (also to save time/cost). As a result, all the Java packages and classes (necessary for JBS project) were duplicated. In this situation, if we update one or more classes in the main project, this (JBS) feature project/application gets outdated (and needs update).
The fact is that this JBS feature project ONLY requires many packages of Java classes (from the main EAR-WAR project), and do not require 99% of the web modules and others. I am removing all the unnecessary things from JBS project. Then I would like to create a JAR library with all the java classes, so JBS project can have a dependency on this JAR.
I do not know if it is a good idea to separate these classes out of the main project (to create another Java project). I would like to continue to have these classes as part of the main project. Then, it will be good, as and when one or more of these classes are changed, a new version of the JAR will be generated (right away). And the JBS project would then make use of this updated JAR.
How can we accomplish this? I understand, through maven, we can do a build/package jar/war/ear on a project of that nature. I am not an expert with maven (and did not learn it systematically).
But, is there a way to create one or more JARs additionally from inside WAR pom.xml? In other words: I mean pom.xml of WAR will create a WAR. In addition to creating a WAR, can maven help create additional JAR? Or can maven create two packages out of one pom.xml?
Or should I create a separate module in the main project with all these packages/classes, and have its own pom.xml to generate the necessary JAR? For this, most probably I need to modify the structure of the main project. I would like to avoid this unless there is no way out.
Can you advice?
It seems like the best thing for you would be to create a multi-module project that both contains the JAR and the other project. This way, you can easily change/build them together, but you create separate artifacts.
I'm trying to create a Spring Boot project with multiple Maven modules. I've used the tutorial at https://spring.io/guides/gs/multi-module/ .
This site recommends a directory tree like this:
parent
application
src, and other subdirectories
pom.xml
library
src, and other subdirectories
pom.xml
pom.xml
I developed this project using Visual Source Code.
Wanting to see the project in another light, I tried to import the project directories into Spring Tool Suite. I'm using a recent one, where you apply the STS plugin to an up-to-date Eclipse installation.
Well, STS doesn't really like this project.
The (File, Open projects from file system) sees the project, but the Finish button doesn't actually do anything.
The (File, Import, General, Existing Projects into Workspace) imports a project, but as a Maven project (no "J" icon). When I try the (Run, Run Configurations) it won't see my project.
How can such a project be made friendly to Spring Tool Suite?
Thanks,
Jerome.
To make multi maven projects what you can do is, simply download two separate maven projects from start.spring.io and then extract them and move both folders to one parent folder and try grabbing the parent folder to Intellij, so it automatically downloads the dependencies and other requirement for the project in which we have two maven projects in one single entity
Eclipse can be a bit confusing with several different Wizards to import projects. Ironically the wizards are supposed to make importing projects easy, and in a sense they do... but... unfortunately picking the right wizard itself can be a bit challenging / confusing. Which wizard you use depends on the type of project.
Since your projects are maven projects, the best wizard to use would be the one for maven projects. You can find it at "File >> Import >> Existing Maven Projects".
So give that a try, point it at the 'parent' folder of your project and you should be presented with a relatively intuitive UI to import all 3 projects and configure them for use in Eclipse.
I need to create a Spring MVC web application where each of the services should be created as a separate JAR file. Some of the docs suggest that multiple Maven modules can be used for this. But what I understood is, that each module also needs to be created as a separate Eclipse project.
Can I have all the controllers, service and DAOs in the same Eclipse project, while still creating separate jars for each service (and a war file for the whole application) with Maven?
Short answer:
Yes, you could create multiple build targets (jar files) out of single project by using maven-jar-plugin (profiles, executions).
https://maven.apache.org/plugins/maven-jar-plugin/
Should you do it?
I believe most people will agree with me that you should not do it, you should stick to one of the most important core concepts of Maven: modularity.
Now, Have you asked yourself the question, Do I really need to create multiple modules (jar Files) for my application? Can I manage all pieces of code in one single project?
Maybe you just need some guidance about how to organize your java packages in one single project.
https://dzone.com/articles/layered-architecture-is-good - Using layered architecture
http://www.javapractices.com/topic/TopicAction.do?Id=205 - Packages by feature vs Layers
NOTE: If you think that your project will grow fast and the number of classes will be a large number, it is probably a good candidate to be a multi module application.
If you still have the feeling that you have to create multiple modules, there are several interesting posts about how to address modularity in the design of applications, in these posts they provide very interesting reasons/criteria why you should split your application into modules.
How to decompose a system into modules?
Spring Java Maven Project + Module Design
Good Luck!
What is the problem of separate modules and hence separate Eclipse projects? If you declare a Maven dependency between the modules, you'll be able to have compile dependencies between the classes in the corresponding Eclipse projects.
So I suppose that it is possible to force multiple Maven modules into one Eclipse project, but I don't know any good reason to do so.
Working in a multi-module Maven project, call it "app." I need to work on the source of one of the dependencies, call it "lib", and be able to easily test/debug "app" against my changes in "lib."
In Eclipse this is an option for its Maven and Gradle plug-ins, and is obvious since Eclipse doesn't bind the concepts of "workspace" and "project" as tightly as IntelliJ does. When I cloned the repo for "lib", IntelliJ offered to create a new project for it, but how do I force "app" to use the local working copy of "lib" for compilation and runtime?
To put it another way, can IntelliJ basically encapsulate doing build install on "lib" behind the scenes so that "app" uses the updated (snapshot) of it?
The obvious, cleanest choice would be to combine the two projects into a common Maven multi-pom project. If that is something you can't do (perhaps the projects belong to different teams etc.), then I could imagine you could fake it by using symlinks.
Create a wrapper project with just a pom file and two modules. Instead of folders for the modules, use symbolic links to the actual file locations. Obviously the reactor root pom would not be the parent pom.
Now open the wrapper pom as IntelliJ project.
I don't know if this works, but it's worth a try.
I have two web application projects in place, Project A and Project B. Project B has war dependency on Project A. Both projects have messages.properties files to handle i18n. However, the location of properties is same for both the projects. I am using maven war overlay plugin to overlay files of Project A on to Project B. If files are in the same location for these two projects, maven will not override Project B's files and leave them as is. However, this leads to maintenance problems as new text for i18n has to be added in messages.properties of both the web applications.
Is there a way to tell maven war overlay plugin to merge the properties files at the time of packaging? The logic of not overriding files when already present serves us well otherwise.
You should be able to achieve this with the Maven Cargo plugin outputting an uberwar.
http://cargo.codehaus.org/Merging+WAR+files
It doesn't know how to merge properties files out of the box, but it's super easy to implement a custom merger, all you need to do is implement org.codehaus.cargo.module.merge.MergeProcessor, and have it available on the classpath.
You probably just want to write a simple merger that can concatenate files together, unless you have duplicate properties then you might need to do something a little more fancy.