I’m trying to embed some JARs into single OSGi bundle using the feature of maven-bundle-plugin
The thing that worries me is that all packages of embedded JARs are put into the Import-Package header of the generated MANIFEST.MF.
If I specify explicitly to use only the packages I need, like in the following snippet:
Import-Package: org.osgi.framework
The build fails with BND error (unresolved references).
So, the question here is how can I build the bundle with embedded JARs with "Import-Package" header I need?
All the packages that are imported in your classes will be imported by bnd. Perhaps you do not want those packages imported because you know that at runtime you won't be needing them. If you cannot stop bnd from importing them, you can make them optional so that your bundle will still resolve even if they are not supplied by another bundle (at wire time). Try to add this:
<Import-Package>*;resolution:=optional<Import-Package>
To your maven bnd configuration in maven.
One possible reason why you are seeing "unexpected" packages in Import-Package header is the following:
A general good practice that supports collaboration model in OSGi is to import all packages that you export -- see this blog post by Peter Kriens for detailed explanation why. Bnd (and hence also maven-bundle-plugin) follows this practice by default and automatically imports all exported packages. Therefore you should first check your Export-Package header and make sure that you export only the packages you want.
Also if you want to export packages from the embedded dependencies then you should be careful to avoid duplication inside your bundle -- see section Embed-Dependency and Export-Package of the maven-bundle-plugin documentation.
You should use Bundle-ClassPath if you want to make classes available inside a bundle that contains JARs e.g.
Bundle-ClassPath: foo.jar,other.jar
Import-Package: org.osgi.framework,org.other.imported
You'll need to list the classes that foo.jar and other.jar import/use, but you won't need to list any of the packages in foo.jar or other.jar unless you're actually exporting them.
You can remove some packages from import-package scope when you embed a JAR into your bundle:
<Import-Package>![package_name9]<Import-Package>
inside pom.xml or if you use external *.bnd files:
Import-Package: ![package_name]
Related
I want to use the import javax.ide in IntelliJ, specifically exploring MetaClass and seeing what it can do. I've downloaded the JAR (198) from https://download.oracle.com/otndocs/jcp/standard_extension_ide-1.0-fr-oth-JSpec/, and I know I'm supposed to somehow add it to dependencies under Project Settings -> Modules -> Dependencies, but I'm not sure what exactly I'm supposed to add from the downloaded folder. The folder containing javax/ide itself is somewhat buried, but I tried adding different levels of directories and none of them worked. The actual folder doesn't even contain java files, it contains a bunch of htmls so I might just be downloading the wrong thing. Thanks for the consideration
I've downloaded the JAR (198) from
It is not a JAR. This is a .zip archive and it does not contain compiled classes in a form of a JAR. It has only source files.
If you are working with a JAR - you need to add such a jar file which contains the needed for your classes into the module's dependencies.
If you do not have the JAR but only have sources - you can create a separate module from these sources and then use it as a module dependency to the module where you want to use these classes.
It's a .jar available in various versions at Maven Repo.
But what category is it? It is published by org.codehaus.groovy, the same outfit that I get my groovy-all dependency from. I also find that import groovy.sql doesn't work in a script unless I specifically include this dependency. So it would appear not to be part of the core language.
Outside a Gradle context I find that I have to manually put the .jar file under ~/.groovy/lib in order to use it. If I put the wrong version (e.g. 2.5.9 for 3.0.2) under ~/.groovy/lib the script won't run... even if I'm not using groovy.sql at all!
Is this a "dependency"? It seems a typically powerful and hassle-free Groovy way of manipulating databases. Are there any other powerful add-on (non-core) Groovy .jar file modules like this, which have to be manually placed under ~/.groovy/lib, that I should know about?
groovy consists of subprojects:
https://github.com/apache/groovy/tree/master/subprojects
and groovy-sql one of the subprojects
all subprojects are published in maven as separate libraries
prior to version 2.5 there was groovy-all-XX.jar that includes all other groovy libraries
https://repo1.maven.org/maven2/org/codehaus/groovy/groovy-all/2.4.19/
however starting from v 2.5 groovy-all represented by groovy-all-XX.pom that depends on all other groovy libraries
https://repo1.maven.org/maven2/org/codehaus/groovy/groovy-all/2.5.0/
so, to include all groovy features you have to specify groovy-all in your maven/gradle/... dependency
and finally useful site to dig dependencies:
https://mvnrepository.com/artifact/org.codehaus.groovy/groovy-all/3.0.2
I have following Maven projects set up:
PM-Core
PM-Web (with a dependency to PM-Core)
Now, this project is used for several clients but for each client there are some small differences: mostly differences in configuration files but some clients also require additional java files (which may not be installed for the other clients).
I've been considering several alternatives on how to support this with maven but am still looking for the perfect solution.
The best solution I can think of is to create a separate maven project for each client (e.g. PM-CLIENT1, ...) which contains only the client specific configuration files and additional java files or jsp's, ... . Next step would be to consider the PM-Web project and the client project as one web project, meaning: have them combined (packaged) into 1 war file with files from the client project having precedence over files from the PM-Web project.
More concrete: running mvn package on PM-Client1 would take everything from PM-Web, add/replace the files from PM-Client1 and then package this into a single war.
So the question is: how to achieve this with maven?
Yes, this can be done using Overlays. The sample on the webpage is exactly what you are talking about.
For the project structure, you could have something like this:
.
|-- PM-Core
|-- PM-WebCommon (of type war, depends on core)
|-- PM-Client1 (of type war, depends on webcommon)
`-- PM-Client2 (of type war, depends on webcommon)
And use overlay in PM-Client1 and PM-Client2 to "merge" them with PM-WebCommon and package wars for each client.
UPDATE I won't cover all the details but I think that declaring the war dependency with a scope of type runtime is required when using overlay, this is how overlay do work (actually, the whole overlay thing is a kind of hack). Now, to solve your eclipse issue, one solution would be to create a JAR containing the classes of the PM-WebCommon project. To do so, use the attachClasses optional parameter and set it to true. This will tell maven to create a PM-WebCommon-<version>-classes.jar that you'll then be able to declare as dependency in PM-Client1 (with a provided scope). For the details, have a look at MWAR-73 and MWAR-131. This is also discussed in the FAQ of the war plugin. Note that this is not a recommended practice, the right way would be to move the classes to a separate module (and this is the other solution I wanted to mention).
UPDATE (201001018): I've tried the attachClasses parameter and it works with version 2.1-beta-1 of the plugin.
You could use profiles see http://maven.apache.org/guides/mini/guide-building-for-different-environments.html and use classifiers to distinguish between the artifacts from the different builds for the same version.
In this setup, you could create additional optional modules for each of your clients specific customisations under the parent project i.e.
+ PM
++ PM-Core
++ PM-Web
++ PM-Client1
++ PM-Client2
Or you could look at using use the maven assembly plugin
Compare also the answers for question different WAR files, shared resources .
I'm happily using the Maven bundle-plugin to create OSGi manifest headers for my modules. However, when there are configuration files that pull in classes which aren't referenced directly in the code, the plugin can't tell which packages it's going to need.
One example is a bundle with domain models that constitute a Persistence Unit for JPA. The driver class is part of the PU configuration and either set in an XML file or at runtime when the EntityManager is instantiated. I have to manually add an Import-Package header for the driver class that I want to load, or I get CNF errors.
Another example is a Struts war, where the web.xml pulls in the Struts dispatcher that's otherwise not found anywhere in the code and has to be manually added to the headers.
How can I avoid this?
I tried adding the required packages as dependencies with a provided scope, but that didn't help.
In the plug-in section of the bnd configuration you can specify plug-ins to analyze these files and contribute to the import-package header. For spring it looks like this:
<_plugin>aQute.lib.spring.SpringComponent</_plugin>
I am not sure, what descriptors are supported on top of spring. Just take a look at the source (it's in the Apache Felix SVN) and see for yourself. In the worst case you have to write your own plug-in, but at least it is possible! Also peter kriens site about the bnd explains the usage and some internals.
Other then that I am not aware of any simple solution.
I currently have an existing plugin, which references a class from a required plugin. I have replaced this code with a reference to a class which is part of my fragment.
I am facing two issues.
If I import my fragment as a jar file, I am not able to see the changes I have made as the plugin running as an eclipse application results in a ClassNotFoundException
To overcome this, I link an additional source (of fragment) to the existing plugin project. However, the link uses an absolute path, and makes it unfit for deployment.
I want to be able to package the plugin with the code modification and be able to "depend" on my fragment code. Is there a way I can add my fragment as a dependency?
For example:
Plugin Project I am changing : org.eclipse.*.editor
it depends on org.eclipse.*.edit
I have a fragment mydomain.*.edit which has org.eclipse.*.edit as host plugin
I want org.eclipse.*.editor to pick up mydomain.*.edit
instead of org.eclipse.*.edit
ps: I have also tried packaging the jar file for the mydomain.*.edit in the plugins directory and try and pick it up from there, it doesnt show up on the list when I click add required plugins on the dependency tab on the plugin.xml file of the org.eclipse.*.editor
Please let me know if I am not clear enough, I will try and rephrase it.
Thanks in advance!
If I understand correctly what you want to do, I don't think that it's possible. You will have to try some other way.
Plugins have dependencies on other plugins. Fragments don't exist as separate runtime entities, but only as extensions of a plugin. So your plugin can only refer to the 'editor' plugin.
Classes provided by a fragment can't (and shouldn't) be accessed directly. They can be returned by the original plugin (A) if they are implementing an executable extension provided by plugin A.
If you refer to the fragment's code from another plugin (B), the classes will be loaded by plugin B's classloader and be different from the ones that are loaded by plugin A.
What is the purpose of your fragment? Do you want to get access to internal code in plugin A? Do you want to extend an eclipse editor?
If you want to extend functionality that the original plugin is not exposing as extensible, I think the only way is to write a plugin, extend the editor class from the original plugin, register it alongside the original one and use it instead.
[Edit] Maybe this link will explain better: Eclipse FAQ
Hope this helps,
Vlad
Thanks Vlad,
Your explanation was very helpful. Unlike the extension based architecture that is truly intended for fragments, I had to modify a certain component in the editor that was not exposed as part of the extension. This modification referred to an external project I created as an fragment but could have been a normal java project packaged a jar file that I could place in the classpath of the editor.
I was able to resolve the dependency issues by placing the jar file in class path, however when I export the plugins and related plugins as jar files and place it in the dropin directory, it does not install correctly. (Nor does placing the jar files in the plugins directory)
The eclipse editor that I am trying to modify uses the EMF project. I have kept the EMF project in the workspace inorder to resolve dependencies of the editor. However when I replace the EMF jar files bundled with eclipse with the one in the workspace, the files that I want to edit are not correctly recognized.
Is there another way of doing this?