As of Java 11 it is necessary to get JAXB from a separate library, not from the JDK. There are plenty of tutorials on the Web showing how to do that, but they all use Maven. The project I need to fix is an Eclipse RCP application. There does not seem to be an easy to make that work with Maven, as Maven essentially takes over most of what Eclipse would do but doesn't have RCP development capabilities.
Sooner or later Maven gets the required libraries. I would like to find another way to get and use whatever libraries are needed, just without using Maven. It should be possible. I just haven't found it.
Thanks.
I did what I wanted by downloading the needed JARs from https://mvnrepository.com/.
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I am a total beginner at maven, I have read about it online but I am still confused how it can be used. I have eclipse Oxygen version installed and when I open projects I can see maven project option is already there. I was even able to create a maven project using YouTube tutorial. But now then I saw popular plugin called m2eclipse but I am not able to comprehend why is it actually used; when my application ran without it.
I am learning maven to get started with spring boot but I am finding it really overwhelming where to begin with, and many of the tutorial sites state to download maven (But maven already comes along with eclipse?)
Please explain.
Apache Maven is a build tool - a tool for compiling the source code of a project into a program that you can run (for example a jar file, or a war file that can be deployed on a Java EE application server). Besides automating all the tasks for building a project, it also gives you a standard way to organize your project and to keep track of dependencies (libraries that your project needs).
Why do you need such a tool?
When you write a small program that consists of one, or maybe a few source files, it's easy enough to compile it by hand on the command line, by directly using the Java compiler javac that comes with the JDK.
But when your project becomes more complex, and you have hundreds or even thousands of source files in multiple modules, it becomes really hard to keep track of everything and cumbersome to compile the files using javac. If your program needs libraries, it becomes even more complex, because you have to make sure that all the libraries are on the classpath, and some libraries need other libraries, which also have to be on the classpath.
A tool such as Maven helps you to compile all the source files in the right order and to keep track of all the libraries. Maven can automatically download libraries from the web and add them to your project, and downloading everything and building the whole project can be done with one simple command such as mvn clean package.
Spring Boot is part of the Spring Framework, which is a huge framework with tons of useful functionality for developing projects in Java. A Spring Boot project typically needs dozens of libraries, and it would be very hard to use if you'd have to keep track of all those libraries by hand - so that's why it uses Maven to manage all of this for you.
A Maven project is configured using a file named pom.xml - in that file, you describe your project and you put a list of libraries that your project needs. When you build your project, Maven will read the pom.xml file and figure out automatically what source files need to be compiled, and what libraries need to be downloaded.
m2eclipse comes preinstalled in Eclipse (at least when selecting "Eclipse for Java developers" or "Eclipse for Java EE developer"), thats why you were able to use Maven by default.
Still you probably want a command line Maven, because that's most likely how it will eventually run on the CI server, sometimes Eclipse Maven installation can produce different result than the command line install.
I've been looking for the answer to this for a few days and have turned up empty.
I'm devving a Confluence plugin that integrates with a 3rd party app. This 3rd party app has a nice REST API and they even provide a Java SDK (yay!). Except.....the Java SDK has bundled a version of Jersey (1.18) that conflicts with Confluence's forked version of Jersey (1.8-atlassian_15). The SDK was not released as a Maven jar (or at least there's no pom.xml included). There ARE other pom.xml in the jar's META-INF for the dependencies it uses, but the SDK itself is just released as a jar download by the vendor.
So as I've done in the past, I mvn install:install-file the sucker with my own groupId and artifactId, thinking it'd be fine. Intellij recognized the library, everything compiled nicely, and then I tried my test call to the REST API. This is when it threw an error that made it evident that there's a conflict between the versions.
SOOOO. Is there anyway to get around this? Can I "sandbox" the SDK jar in a way the executes code in its own deal without being exposed to the nasties of Confluence's builtin version of libraries the SDK uses? I have a feeling that even after the Jersey dependency is resolved (if that's even possible) there will be other issues....The SDK also bundles the specific version of Jackson, Swagger, etc. with it.
I attempted to decompile the jar and include the decompiled code in my project, but that just had all of issues I'd rather not deal with ever again.
I have reached out the SDK devs to see if they could release a more maven-friendly release, but I'm not hopeful this will be done at all, and even it is, their release cycle is much different than my own requirements (read: I need a solution now). This is my last-ditch effort before rewriting the REST client from scratch.
Can I "sandbox" the SDK jar in a way the executes code in its own deal without being exposed to the nasties of Confluence's builtin version of libraries the SDK uses?
Sure you can. Often-used way to do this is to use Maven shade plugin that transforms an existing jar to a shaded jar, using another package hierarchy and getting rid of the package naming conflict. See also the documentation about relocating packages. I suggest you use that - that's what I've done in cases like this (though I haven't done confluence plugin development, but it should be the same thing as with other platforms).
Has anyone got the Acceleo Maven build to work?
If so what combination of Maven, Tycho, Eclipse, Acceleo, UML2/ecore worked for you?
And as a supplementary question do you still need to adjust the Java classes and config files before running the build (as was required for the old ANT build)?
To be clearer tycho does not like Maven 3.3, Maven 3.3 is the default with Luna. Every version of Eclipse has a different version of the ecore/uml model built in so migrating the Acceleo templates to another version of eclipse requires changes in all "module" definitions and hacking the version inside the UML models, so, its tedious trying to work out which versions are compatible.
I just wondered if someone had a working setup where all the components worked together.
After much trial and error:-
Eclipse Luna
Comes with Eclipse m2e 1.5
ecore uml2 version 5.0.2
Acceleo 3.5.1
Maven 3.0.5
org.eclipse.acceleo:org.eclipse.acceleo.maven:3.5.0-SNAPSHOT
All work together without the usual class not found and missing jars.
However I have yet to build a working pom that actually generates some
template output.
Interestingly the ANT build seems to work fine.
In the end it was just easier to knock up a .bat script to run
the generate and build.
You can have a look at the UML to Java generator of the Eclipse Foundation for the configuration of the pom.xml. For additional information on the use of maven with Acceleo, look at the dedicated page on the wiki.
You do not need to modify any Java class or configuration file now.
There is a lot of talk about maven being the dependency resolution engine of choice (or Aether more specifically). What is the result of this change from an application development perspective? Going forward am I meant to use an external pom file to capture my dependencies rather than BuildConfig? Do I run create-pom on legacy projects upgraded to 2.3x? Is there a recommended approach?
The recommended approach is to express your dependencies in BuildConfig.groovy and let Grails take care of it from there. You don't need to generate a pom file unless you are trying to integrate your Grails build as part of some other build (like a Maven build). The normal thing to do, unless you have some specific reason to do otherwise, is to use the Grails build system which by default in recent versions will use aether to do the resolution, but that is largely an implementation detail and all you typically have to interact with is BuildConfig.groovy.
I hope that helps.
How do you download Spring Framework jars if you can't stand Maven or any of the other build management tools. From what I can tell it seems you have to spend many frustrating hours on Google to find out how to do this. I thought Spring was supposed to be easy. All I'm trying to do is to write a simple Hello World application using Eclipse and Tomcat. Why is it so difficult with Spring 3?
go there
http://repo.spring.io/release/org/springframework/spring/
you can see all versions, like old school
Why can't you stand Maven? I like Maven, but I really like Gradle.
Either way, if you only build with your IDE, you can't automate your build (so no chance at continuous integration/delivery), and it's tough to integrate new members of your team. Specifically with this question about Spring dependencies, it is a lot easier to automate management of transitive dependencies rather than download them all yourself--and figuring out which new jars to download by tracing through one NoClassDefFoundError after another.
I think the Spring guys can't imagine why anyone would want to endure all these downsides. But it's your project and you should do what you think is right.
So if you must, grab the jars starting with this one from Maven Central yourself and have some fun.
That's funny. It seems everyone wants you to use a dependency management tool. You can always browse a maven repository and download the parts you need:
http://mvnrepository.com/artifact/org.springframework