I've got a couple of java projects that depend on the same piece of code. Lets call them:
Project A
Project B
ComponentX.java
The projects are set up like this:
Project A > ComponentX.java
Project B > ComponentX.JAR
This set up where Project B contains ComponentX's jar file is inconvenient. Any time I make a change to ComponentX.java, I need to remember to export the Jar to Project B. It also makes debugging Project B difficult. There has to be a better way, I just don't know what to google. I'm using Eclipse. I use Maven so any solution using that would be Ok, although I'm hoping that there is a simple Eclipse based solution.
I'm guessing I'll need to move componentX into its own project and somehow make the other two depend on it.
You most likely want to create a new library project that will be used by both Project A and Project B as a standard Maven <dependency>.
There are few guides available online. If your projects are all part of the same multi-module Maven build you can take a look at Creating a Multi Module Project guide on spring.io.
So I had a lightbulb moment. Any maven project can be imported into any other maven project the exact same way you'd import any other dependency. Seems obvious now but I've only ever imported libraries other people wrote.
So if you've got three projects:
WebApp
DesktopApp
Dependency
Where both WebApp and Desktop need to reference Dependency. This could also apply in a case where there is repeated code in two projects, just pull that out into it's own project and remove it from both.
Simply make Dependency project a Maven project by right clicking > Configure > Convert to Maven Project. You'll get a .pom file with something like this at the top:
<groupId>Dependency</groupId>
<artifactId>Dependency</artifactId>
<version>0.0.1-SNAPSHOT</version>
Then all you have to do is add that as a dependency to any other project's .pom that needs access to it:
<dependency>
<groupId>Dependency</groupId>
<artifactId>Dependency</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
That's it
Related
Currently, I have a maven project that has a server running (using Jersey REST API). I also have a java project, I need to move all the contents of the java project into the maven project. The maven project is a subset of the java project. However, the maven project only displays the parts of the java project. However, I want a project that allows me to use maven and displays all of the other details from the java project.
I would've copied and pasted however I'm using git so I want to also preserve history.
I was thinking it would be easier to nest the maven project inside the java project but I don't know if that's possible.
Here's a picture of my package explorer to help explain everything.
Package explorer showing the maven project being a subset of the java project.
What I've tried is converting the java project into a maven project and then updating the pom.xml but then it doesn't link to the web.xml. Also, it tries to run the server with the name of the project name TeamProject. When infact it should run the url with the name client_server
I was considering just copying and pasting all the code into the maven project (from the Teamproject java project).
Actually nesting the java project inside the Maven project makes more sense, as it is the purpose of Maven to handle a project lifecycle. (also by default Maven will look for sources in the src/ folder which should ease the task of putting your Java project inside Maven's hands)
There are several possibilities I would see:
Copy your java project in the src/ of your client project and update maven accordingly (within the pom.xml)
Make your Java project a Maven project and aggregate the two projects in a parent pom (see Multi module maven project example)
Make your Java project a Maven project, and decide of a "Master" project between it and the client and compose one with the other (not sure that's a great solution)
Nesting your Maven project inside the Java project would not be so great because Maven could only handle the client and not your Java project, and then you'd miss on numerous functionalities offered by Maven (just look at how simple it is to get dependencies compared to downloading a jar and including it on the build path manually)
I have 3 projects, A->B->C in that dependency order. Currently everytime I make a change to B or C I have to go to the directory and do a mvn clean install in order to install it into the local repository. It is troublesome if I have to do this every time the projects updates.
How can I do it such that every time I do a mvn clean package on A, it will automatically build and install my dependent projects B and C into the local repository?
Create a parent project for all your projects A,B,C and then add all your child project on the parent pom.xml file something like this
<modules>
<module>A</module>
<module>B</module>
<module>C</module>
</modules>
Its called maven multi module project mentioned by #khmarbaise
Here are some example for this
How do I create a multi-module project in Eclipse?
Maven Multi module tutorial
Guide to Working with Multiple Modules
By use of multi module project you will get plenty of benefits like
Anytime you can add any new project with all of the current project
Separation of project is good for code cleanup
You can build Single project or You can build all project in one go.
Duplicacy of jar can be easily ignore .
Maven take care of the build order for you.
One single Jenkins job to build everything.
Plenty of other benefits.But remember if there will some pros then cons also there,its totally now what you want to use .
You can follow the solution I provided to the question Maven 2 Projects, since it is the pattern I usually use when building project with a certain complexity.
Summarizing you would have to create a main Maven project which has three submodules, say master, platform and parent.
The main project has simply the order in which the other projects will be evaluated by Maven
The master pom contains the list of project to be built and their order (aka Reactor order)
The platform pom contains all information about your platform, like JDK version, maven plugin versions, encoding and so on.
The parent pom has the platform pom as a parent and contains all global GAV information about the dependencies you are going to use in your project (Spring, CXF, junit, log4j etc.)
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.
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 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