I have added a Java project dependency in Maven dependencies however if I add the same dependency in build path it works. What is the difference between these 2 methods?
Adding your project as maven dependency would mean that
You don't have to bundle your jar with your project.
You don't check in your .classpath and .project eclipse meta files in your source control
Any other programmer in your organization will be able to build your application.
You should not manually add jar file in eclipse build path. Its an anti pattern.
Both works because eventually your application need classpath which is set both by adding dependency manually as well as adding in build path.
Related
I have a maven project that uses other small projects. And I added them to master's pom file.
So my Eclipse project properties looks like following:
>Master project
>Java Resources
>Libraries
>JRE System Library
>Maven dependencies
>smallProj1.jar
>smallProj2.jar
The thing is I do not have the all code for smallProj1 and smallProj2 and whenever add them to my workspace Eclipse overrides the maven dependencies and simply calls the two projects instead the jar files from my local maven repository and then I have all over the code those red underlines. Project properties in Eclipse looks as following after I add them to my workspace:
>Master project
>smallProj1
>smallProj2
>Java Resources
>Libraries
>JRE System Library
>Maven dependencies
>smallProj1 (not jar anymore - folder)
>smallProj2 (not jar anymore - folder)
Since I also want to have a look to smallProj1 and smallProj2 code while I am coding, I want to keep them both in my workspace. But I want my Master project to use the jar files that I provided, not the small projects in the workspace.
Any ideas on that?
You could right click on a project and set "Maven" -> "Disable Workspace Resolution". This will let Maven find the dependencies from Maven and not within the workspace. I don't think it is possible to do this on a dependency basis.
But I think in your case it would be better to fix the broken smallProjX in your workspace (as they exactly contain the code you need), so that the master project could be build correctly.
I have a project in Eclipse which I built using Maven and it has hundreds of JARs as reference libraries. Is there a way to include all these reference libraries to another project?
Since the original project involved Maven dependencies, there are two ways of doing this.
- Maven
To accomplish this in Maven style refer to this question. How to add "Maven Managed Dependencies" library in build path eclipse?
- Adding a project as dependency
The more simpler way of doing this (for beginners and testers), is to just include the original project as a dependency to the new project.
In your original project, travel to Properties > Java Build Path > Order and Export.
Select all the dependencies that you want for your new project.
In your new project, travel to Properties > Java Build Path > Projects. Now add the original project.
I have an existing eclipse project with standard dependencies in the classpath. I need to add a new dependency through maven but the rest of the dependencies need to stay there as jars bundled with the project.
I am using m2e, if I right click on the project --> maven --> enable maven, a pom file is created. At this stage I can add my new dependency through the pom file but all the existing dependencies seem to be gone from the classpath.
Hence the question: Is there a way to create a hybrid project that has both standard dependencies and maven dependencies?
You could add your legacy dependencies by using the scope "system" (and the tag "systemPath") ?
See http://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html.
I don't think you should even attempt to create such a thing, and I don't know why you would want to.
If you want to use Maven, then you should define all your dependencies in your pom so that a maven build will actually work. If all your dependencies aren't defined, how do you expect maven to build your project?
You need to decide which means of dependency resolution you want to use instead of trying to mix two together.
I have a dependency on clj-record in my CounterClockwise project. What's the best way to manage this? Copy the source code or compile to a JAR and add it as a referenced library?
There are tools to help you:
http://github.com/technomancy/leiningen <- project based
http://github.com/liebke/cljr <- dependencies not project based
http://github.com/ninjudd/cake <- alternative build tool
Assuming your dependencies are available in a Maven repo (like central or clojars), you have a couple of options.
First, if you're using Leiningen, there is an eclipse plugin for it now that will manage project dependencies for you, based on the dependencies you define in your project.clj file. The plugin is in beta now, but has been working great for me so far. (Note that it uses Leiningen 2.0 under the covers, though that detail won't matter for many (most?) simple cases.)
If you're using Maven, the m2eclipse plugin makes it so that the dependencies you declare in your Maven pom.xml are automatically added to your eclipse project's build path, and are therefore available in CCW REPLs and such.
there seems to be no pattern for specifying dependencies apart from hacking the code into your project or building a jar externally.
Of course you can, just as with any java project. While dependency resolution isn't tied into eclipse (yet), once you retrieve the deps (via one of the command line tools nickik listed), you can specify which jars are to be included in the java build path of your eclipse project:
Retrieve the deps via cake, leiningen, etc.
Refresh the eclipse project so you see the deps (usually in the lib directory)
Highlight the jars you want eclipse to know about
Right-click, select Build Path > Add to Build Path
That's it. You can fiddle with the build path by going to the Java Build Path section of the project's properties window.
I tried to add the apache vfs jar file as the runtime dependency. Even though it throws the below error:
java.lang.ClassNotFoundException: org.apache.commons.vfs.VFS
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:489)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:405)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:393)
at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:105)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
at file_explorer.View.setInput(View.java:295)
at file_explorer.View.initialize(View.java:130)
How can i resolve this, thanks in advance.
If you are looking for adding the required jars to your project classpath.Add the required files to lib directory in the project structure.Then from project click the 'run time' tab of plugin.xml and add the required jars from the lib directory to the project classpath.
The best way to include external Jar in Eclipse RCP application is to package it as a plugin and then use classic plugin dependency.
Just create a new plugin containing only your Jar. Then in the build tab of the manifest editor, add your jar to the classpath (at the bottom right) and export all its packages in this same runtime tab. Also be sure to check that you jar is checked in the Build tab.
Nevertheless you should be able to use the jar in a Given plugin source code if you only add it to the classpath as I mentioned previously.
Because some other of your plugins may be interested in using the vfs jar and for separtion of concerns matter I think you should wrap it in its own plugin
The easiest way is to find bundle in an existing OSGI bundle repository.
http://bundles.osgi.org/Main/Repository
http://www.springsource.com/repository/app/
http://www.eclipse.org/orbit/
http://www.knopflerfish.org/repo/index.html
springsource repo contains apache VFS bundle
Then you need to add the bundle to the target platform (or just copy it to the dropins folder)
In order to properly install bundle into a newer version of eclipse you should use an existing p2 repository and install bundle from p2 repository into your runtime platform. There are two ways: you could use existing one (like orbit p2 repo), or you could create your own using p2 publisher as described at https://docs.sonatype.org/display/TYCHO/How+to+make+existing+OSGi+bundles+consumable+by+Tycho
Eclipse RCP is an OSGi environment which extends the Java dependency model, so you can't simply take a jar file and hope it works. To use an external jar, you have to build it to a plugin first, which p2-maven-plugin can help, you can follow the readme document.
With the plugin ready, you should install the plugin and add it to MANIFEST.MF. Then restart Eclipse to make the plugin work.
A more easily way, you needn't install the plugin, just follow(but build the jar):
go to plugin.xml -> Runtime tab;
click Add at the classpath section, then add the plugin to classpath;
make sure there is . path in the text area, otherwise New it.