External jars in eclipse plug-in - java

I'm creating an eclipse plug-in and I'm having trouble with external jars. In my plug-in I start an application which requires some external jars. What do I have to do to export them automatically with the rest of the plug-in?
Thanks in advance :)

Open your plugin.xml
Go to Runtime tab and add your JAR in the classpath section

By following the steps below, the external JARs will be included when you export your plug-in:
Copy the required external JAR files into a folder in your plug-in project; I like to call this folder lib, but whatever works for you.
Open the build.properties in your plug-in project and check the JARs you want to include in the build in the Binary Build section on the left.

This is an easy way, though it does create an additional plug-in.
In Eclipse:
Choose New>Other, then Plug-in Development>Plug-in from existing JAR archives.
Choose the jars you want to include.
On the next page, configure the plug-in.
In your plug-in's manifest, add the new plug-in as a dependency.
In your plug-in's Properties, add the new project under Java Build Path on the Projects tab.
Edit: You may be able to combine the jars into your plug-in by instead combining both suggestions of Zsolt and user714965 below.

This is what has worked for me. If they are truly external, and this is a project for your company that is not going to be in the "wild" and you control the environment, and you have them out on the file system say at /opt/java/lib/somedir/some.jar you can tell the bundle where to find them by adding them to the Bundle-ClassPath entry in the MANIFEST.MF under META-INF. The syntax is:
Bundle-ClassPath: .,
external:/opt/java/lib/somedir/some.jar,
external:/opt/java/lib/someotherdir/someother.jar
Also it would be prudent to use these in your build path so that you are working with the same jars in both build and runtime environments.
I have done this where the Jars are multi-purpose (such as apache-commons) on our file systems and again we control the environment.
Reference the following:
http://www.eclipsezone.com/eclipse/forums/t51870.html

Copy the required external JAR files into a folder in your plug-in project; I like to call this folder lib, but whatever works for you.
..but as apposed to Zsolt Török (his solution did not work for me) I double-clicked on the plugin.xml, went to the build tab, at the bottom, I clicked Add JARs..., and hey presto, it showed my project, and I then navigated to lib and included the external jar, as per step 1.

The approach from Andy Thomas mostly works, but you also need to export the packages needed by the existing plugin in the new wrapper plugin so that they can be accessed by the plugin at runtime.

Related

Manipulate the java class path of an Eclipse plugin?

I am working on a plugin that consist of a homemade view to Eclipse.
When I run the plugin and display the classpath using System.getProperty("java.class.path")
I get this as output : D:\Programs\eclipse\plugins\org.eclipse.equinox.launcher_1.3.100.v20150511-1540.jar
I would like to add some .jar files for the proper functioning of my view, but I can't figure out how... I guess you can do it by adding some specifications to the MANIFEST.MF of the plugin but I don't know how to do it propely.
any ideas ?
Each Eclipse plugin has its own classpath. To use additional jars in the plugin you need to include them in the plugin.
Add your jars to the plugin directory. Usually they are put in a 'lib' directory.
Open the plugin MANIFEST.MF editor and on the 'Runtime' tab in the 'Classpath' section click the 'Add...' button and add your jars to the class path.
On the 'Build' tab of the editor make sure the 'lib' folder is include in the Binary Build section.
Your MANIFEST.MF should end up with a `Bundle-Classpath' entry that looks something like:
Bundle-ClassPath: .,
lib/jogg-0.0.7.jar,
lib/jorbis-0.0.15.jar,
lib/vorbisspi1.0.2.jar
(here I have 3 jars in a lib folder).
The build.properties file should be something like:
bin.includes = META-INF/,\
.,\
plugin.xml,\
lib/,\
lib/jogg-0.0.7.jar,\
lib/jorbis-0.0.15.jar,\
lib/vorbisspi1.0.2.jar
For Compile time we need to add it to the Project runtime library.
For the run time you have to package the jar either in your EAR/WAR file or Load it to the Application server as a App server libraries.
Please let me know if you need further assistance on this.
The best approach I've found is to create a lib directory in your Eclipse project (where your view is contained). Place your .jar files in said lib directory.
Then using the editor on the MANIFEST.MF, you add the .jar files to the classpath. If you wish to export the packages, you then add to the Exported Packages as well.
Depending upon what you are doing, you may wish/need to also update the Build Configuration.
If you examine the MANIFEST.MF file itself, you will then see an entry for Bundle-ClassPath. It will list your entries. Here it has the standard "." for the project, a resources/ directory that we export, and a couple of .jar files.
Bundle-ClassPath: .,
resources/,
lib/aopalliance-1.0.jar,
lib/apccore-client-2.11.8.jar,
lib/cglib-nodep-2.2.2.jar,
lib/ehcache-2.10.3.jar,
...
Note that in our experience, it is also necessary to adjust the Java Build Path from the Properties of the project itself. A user commented that this step may not be necessary. We are on an older version of Eclipse due to our product, so YMMV, If needed (usually compile failures are the indicator), you then need to add, via the properties context menu on the project, the .jar files to the "Java Build Path" (you can do the same with a resources directory).
This will allow you to properly build using the .jar files.

Add library into jar of project

My problem is with a project where I use the POI library. It's from apache and allows you to work with excel,word, ... .
I had to add some jar files to my library and it runs perfect.
The problem is when I put my JAR file somewhere else.
It gives me the errors it can't find the librarys.
Is there a way I can put my librarys into the 1 jar?
I already tried to add my lib folder as source package but that didn't help.
there is a Maven plugin for Eclipse called M2Eclipse, which will read a POM and construct a classpath out of jars it finds in the local repository and any remote repositories you've configured. It behaves largely like Maven does in terms of finding the latest version for a given jar (if you've specified a version range in your POM).
You can also have a look on this
http://fredpuls.com/site/softwaredevelopment/java/deploy/five_strategies_for_managing_j.htm
You want to make a 'shaded' or 'uber' jar, which has all of its dependencies included
There is a maven plugin for building a shaded jar.
https://maven.apache.org/plugins/maven-shade-plugin/
For me the fastest/ easiest solution was to just open my project in eclips and export is a runable JAR then it adds the librarys to the JAR.
NetBeans builds your application into the project's dist folder. There is also a readme file in it, that tells you, you should distribute the contents of that folder...
Edit
Remove the lib folder, that is shown on the second image, from your sources.

How to add a JAR to an Eclipse plugin I am developing?

I am developing an eclipse plugin. It has other plugin/feature dependencies. However I want to add my own favorite JAR/libriaries to it, like say logback for example. How can I do this so that when I eventually deploy it to an update site, it will have these jars on the classpath?
Also, I am currently using eclipse to run the plugin (it opens another instance of eclipse) to run this. This will also need to have the jar on the classpath.
You can try these steps :-
Use Import>File System to import the jar files into your plugin project, say in the /lib directory.
Use "Add..." to add the jars to the classpath section of the plugin.xml>Runtime tab.
Use "New..." to add "." library back (with no quotes, of course).
make sure your binary build exports the new jar files on the plugin.xml>Build tab.
save.
on the project, use context menu>PDE Tools>Update Classpath to correctly add the jars to the eclipse project classpath.
In plugin-manifest editor select Runtime tab and add you jar in classpath section.

How Can I Add the Apache POI Library in and Eclipse Project?

I download the Apache POI from apache.org but don't know how use it with one of my existing project in Eclipse.
There are several ways, some good, some bad...
Add external Jar - as jjnguy says will work. However, not a good option...
The problem is that if you share your project with someone else and they have the jar in a different spot, they'll get build path errors
Add variable - similar to add external jar, but much more flexible. You can define a classpath variable (under Java prefs) that represents the dir containing jar. In your project, when you add variable, you choose the var you defined and press "extend" to specify the actual jar. As long as you and other developers of your project define the variable, you can have the jar in different spots if you like
Add the jar to your project - create a dir in your project (optional, maybe call it lib) and import the jar into it using File->Import or if your OS supports, drag it as an icon into the folder (On windows I open an explorer window and drag it from there into the folder in eclipse). Then, right-click the jar and select Build-Path->Add to build path.
Add the jar in a separate project and reference it. Add the jar as mentioned in the last bullet to a separate project for that jar. Choose Build-Path->Configure Build path from the project. Go to the "order and export" tab and make sure the jar is checked. Now you can configure your project to reference the new project. This makes things more modular.
Create a user library - under Java prefs you can define a "user library" that contains the jar. This is somewhat similar to a classpath variable, but can reference multiple jars and you only have to add it once to the project.
Create a classpath container plugin. This is more complex, but is a nice option if you are providing a set of plugins for folks. A classpath container can be added like a library to a project and it can manage the jars, even searching for them if you want it to.
You can find the option to add external jars to a project in: Project > Properties > Java Build Path > Libraries tab.
Click on 'Add External Jar' and find where you have the POI library.

Runtime issues during developing an Eclipse Plugin

Right now, I am trying to create a plug-in of Eclipse which depends on other jar; therefore, I created a plug-in base on the jar and deployed it under my Eclipses' plugin foler. It works well when I start it from my working environment via an Eclipse. However, as soon as I have exported it into a jar and have deployed into Eclipse, it not work any more as it couldn't find out the dependent jar. What happened and how to solve the issue? Does anyone know that? please save me.
The MANIFEST.MF has a Tab called "Dependencies" in which alle plugins should placed the current plugin depends on.
At runtime you have to place the "dependencies" plugins in the same folder as the one you want to start or you want to work with.
When a plugin has jars it should use, you have to put the jars to the "Runtime" Classpath Entry and you should add the jar to the "Build" Binary Build entry.
Also, does the plugin.xml associated with your 'external jar' plugin does export the right packages ?
Did you check this article describing all steps necessary to packaging 3rd party jars as plug-ins ?
Other very important points are described in the article PDE and 3rdParty Bundles in OSGI Enterprise apps with rules such as:
Always put dependent JAR Files in separate bundles and describe the dependencies in your Manifest file. Don't hide those JARs in your own bundle.
If possible use Import-Package to resolve your dependencies.
Export only your "public" packages - no internal.
Use Require-Bundle only to resolve dependencies inside your own „universe“, not against common bundles.
Always version Require-Bundle, Import-Package und Export-Package.
Require-Bundle always has a dependency to a bundle with a specific name.
Import-Package isn't dependent from the name of the bundle, so its more flexible. Of course its more work to look at your packages and decide which you need to import or to export compared to a one-liner with Require-Bundle
If a bundle itself contains packages inside the bundle and exports them, never put these packages also into the Manifest as imported packages.
Before deploying of a bundle as plug-in be sure the Package-Uses are re-calculated. Wrong Package-Use entries for exported packages can stop PDE to export your Plug-In.
The working behavior out of Eclipse is normal, since the dependent jar is in the classpath of the project.
Have you had a look at the plugin folder you deployed? I suspect, that the dependency isn't contained in the plugin folder.
I just had a similar problem. I fixed it using the plugin view:
Add jar using the Classpath section of the Runtime tab
Use the Organise Manifest Wizard from the Overview tab to do all the required manifest changes
Use the Export Wizard from the Overview tab to export the finished plugin.
Note I am using Eclipse 3.3 so your milage may vary.

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