Eclipse Target Platform. Via a target platform you define which set of plug-ins and what version of Eclipse you develop against. This tutorial describes how to setup your target platform for Eclipse Plug-in and RCP development.
1. Configuring the available libraries via a target platform
Eclipse uses target definitions to define the target platform, i.e. the set of available Java libraries (via JAR files) for Eclipse development.
The Target Platform refers to the plug-ins which your workspace will be built and run against. I These libraries can be used in addition to the plug-in projects in your workspace.
If no explicit target definition is defined and activated, the Eclipse IDE are used as target platform. To avoid that each developer uses his local IDE libraries to compile against, it is good practice to use a target definition file. This way the plug-in dependencies and the used versions are controlled and specified during the development. A target definition file is typically shared between the developers to ensure that everyone is using the same basis for development.
1.1. Creating a target platform
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The definition of a target platform is demonstrated in detail in the a later exercises. |
A target definition file can be created via the menu.
You can add new libraries via the Add… button in the Locations section. You can add:
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Eclipse (p2) update sites
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File locations
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Standard Java libraries from Maven repositories (require an IDE extension)
You can define a target platform based on (p2) update sites and the file system. The Eclipse Maven tooling also add the option to use standard Java libraries from Maven.
The following is a example of a target definition file:
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<?pde version="3.8"?>
<target name="target-platform">
<locations>
<location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
<repository location="https://download.eclipse.org/releases/latest"/>
<unit id="org.eclipse.equinox.compendium.sdk.feature.group" version="3.20.400.v20201102-2042"/>
<unit id="org.eclipse.equinox.core.feature.feature.group" version="1.13.0.v20201107-1818"/>
</location>
</locations>
</target>|
The
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1.2. Using a target platform
You can activate and switch the target platform in the Eclipse Preferences. Select . It is also possible to active a target platform via its editor via the Set as Active Target Platform link on the first page.
2. Exercise: Creating a target platform definition file
In this exercise you create a target definition file to define the libraries available for your Eclipse development.
2.1. Create a project of type general
Create a new project named target-platform of type General via the menu path.
2.2. Create a target definition file
Create a new target definition file via the menu path.
Use target-platform as file name and press the Finish button.
This creates a new file and opens the Target Definition editor.
2.3. Setting up a target platform for RCP or OSGi development
The following describes the definition of two target platforms. One for Eclipse IDE / RCP development and the other one for OSGi development.
3. Exercise: Setting up a target platform for Eclipse based development
In this exercise you add libraries to your target definition so that you can develop Eclipse plug-ins for the IDE or RCP applications.
3.1. Add content to the target platform
Ensure you target definition file is open in the Target Definition editor and press the Add… button.
Select Software site in the following dialog.
| The Maven entry may be missing in your current installation, for this exercise this entry is not necessary. |
Press the Next button and enter the following URL in the Work with selection box.
https://download.eclipse.org/releases/latest|
Latest points to the latest release, you can also select a specific release to build against.
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Remove the Group by Category flag and add the following components:
| Component | Description |
|---|---|
Eclipse Platform SDK |
Components for Eclipse plug-in development |
Equinox Target Components |
The native launchers for the platform |
Save the target definition file.
3.2. Example solution for the RCP target platform
If you check the Source tab of target platform, it should look similar to the following listing.
Show Solution
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<?pde version="3.8"?>
<target name="target-platform">
<locations>
<location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
<repository location="https://download.eclipse.org/releases/latest"/>
<unit id="org.eclipse.equinox.sdk.feature.group" version="0.0.0"/>
<unit id="org.eclipse.platform.sdk" version="0.0.0"/>
</location>
</locations>
</target>| The versions have manually set to 0.0.0 via the text which mean "any version". This allows you to change the update site without updating the version numbers. |
3.3. Add option to use NatTable in your code
NatTable is an advanced framework for building tables and trees.
We want to be able to use NatTable in our development environment.
Therefore, modify your target platform.
Open the target definition file in the target definition editor and add the following entries.
| Name | URL |
|---|---|
NatTable update site |
https://download.eclipse.org/nattable/releases/1.6.0/repository/ |
vogella sample data model |
https://dl.bintray.com/vogellacompany/codeexamples-javadatamodel/updatesite/1.4.0/ |
The data model is of course not necessary for the usage of Nattable but will give us a simple data model to use NatTable.
The following features of the update sites above should be added to the target definition file.
Ensure you activate this target definition by clicking on the Set as Target Platform link in the target definition editor.
A target platform file which supports NatTable should therefore have at least the following entries, you may have more entries.
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<?pde version="3.8"?>
<target name="target-platform">
<locations>
<location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
<repository location="https://download.eclipse.org/releases/latest"/>
<unit id="org.eclipse.equinox.executable.feature.group" version="0.0.0"/>
<unit id="org.eclipse.sdk.feature.group" version="0.0.0"/>
</location>
<location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
<repository location="https://download.eclipse.org/nattable/releases/1.6.0/repository/"/>
<unit id="org.eclipse.nebula.widgets.nattable.core.feature.feature.group" version="0.0.0"/>
<unit id="org.eclipse.nebula.widgets.nattable.core.source.feature.feature.group" version="0.0.0"/>
<unit id="org.eclipse.nebula.widgets.nattable.extension.e4.feature.feature.group" version="0.0.0"/>
<unit id="org.eclipse.nebula.widgets.nattable.extension.e4.source.feature.feature.group" version="0.0.0"/>
<unit id="org.eclipse.nebula.widgets.nattable.extension.glazedlists.feature.feature.group" version="0.0.0"/>
<unit id="org.eclipse.nebula.widgets.nattable.extension.glazedlists.source.feature.feature.group" version="0.0.0"/>
<unit id="org.eclipse.nebula.widgets.nattable.extension.nebula.feature.feature.group" version="0.0.0"/>
<unit id="org.eclipse.nebula.widgets.nattable.extension.nebula.source.feature.feature.group" version="0.0.0"/>
<unit id="org.eclipse.nebula.widgets.nattable.extension.poi.feature.feature.group" version="0.0.0"/>
<unit id="org.eclipse.nebula.widgets.nattable.extension.poi.source.feature.feature.group" version="0.0.0"/>
</location>
<location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
<repository location="https://dl.bintray.com/vogellacompany/codeexamples-javadatamodel/updatesite/1.4.0/"/>
<unit id="com.vogella.model.feature.feature.group" version="0.0.0"/>
<unit id="com.vogella.model.feature.source.feature.group" version="0.0.0"/>
</location>
</locations>
</target>4. Exercise: Setting up a target platform for OSGi development
In this exercise you create a target definition which can be used to develop OSGi based command line applications.
4.1. Add content for OSGi development
Press the Add… button.
Select Software site in the following dialog.
Depending on your installation, you may see different entries in the dialog, e.g. you may see an additional entry named Maven.
Press the Next button and enter the following URL in the Work with selection box.
https://download.eclipse.org/releases/latest|
https://download.eclipse.org/releases/latest points to the latest Eclipse release, you can also select a specific release to build against.
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Remove the Group by Category flag and add the following components:
| Component | Description |
|---|---|
Equinox Compendium SDK |
Additional OSGi services |
Equinox Core Function |
Basis runtime and functionality of OSGi |
Save the target definition file.
4.2. Example solution for the target platform
If you check the content of the target platform via the Source tab, it should look similar to the following listing.
Please note that the version number has been set to 0.0.0 in the listing, so that
Show Solution
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<?pde version="3.8"?>
<target name="target-platform">
<locations>
<location includeAllPlatforms="false" includeConfigurePhase="true" includeMode="planner" includeSource="true" type="InstallableUnit">
<repository location="https://download.eclipse.org/releases/latest"/>
<unit id="org.eclipse.equinox.compendium.sdk.feature.group" version="0.0.0"/>
<unit id="org.eclipse.equinox.core.feature.feature.group" version="0.0.0"/>
</location>
</locations>
</target>5. Activating the target platform for developemt and issue resolution
5.1. Use the target definition file
After saving the target definition file, it is resolved which will take a while, you can see the progress via the toolbar of your IDE.
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Avoid using the Eclipse IDE until the target is resolved. Resolving targets is using the network and you do not want to interrupt this, as this might result in an inconsistent target definition. |
After the target is resolved, press the Set as Active Target Platform to activate it. Please note that your version numbers might be different.
5.2. Remove version dependencies
In case you don’t want to fix the version of a bundle in your target platform you can remove the version number. For example if you are using an update site which provides the latest version, you should remove the version number so that your target platform can select the latest version of your plug-ins.
As we are building in this exercise against the latest release of Eclipse we want to remove the version numbers.
Therefore, replace all numbers with 0.0.0.
0.0.0 is a placeholder and tells the system to us any available number.
For this, select the Source tab in the target platform editor and replace the numbers with 0.0.0.
This way, you will always use the latest available version from your update site.
5.3. Solving potential issues with your target definition
Your target platform depends on external update sites and the availability of the network. Theses update sites might change over time, so you should be able to revert your target platform settings in case you face issues.
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If you face issues with your target platform, switch to the IDE as target platform and afterwards switch back to your target definition. That sometimes solves target resolution issues. |
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If the target definition does not work, e.g. because of network issues, you can use your Eclipse IDE as target platform via .  |
6. Optional exercise: Mirroring p2 update
To avoid long running network operations to server outside of the own network, you can mirror p2 update sites.
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Mirroing with Tycho p2 explains how to mirror an update site with Maven. |
One way is to use Eclipse to mirror a update site, for this you need to mirror the metadata and the artifacts.
The following is an example for Windows, which mirrors the latest update site to C:\Users\Lars\mirror.
./eclipsec -nosplash -verbose -application org.eclipse.equinox.p2.metadata.repository.mirrorApplication -source https://download.eclipse.org/releases/latest -destination C:\Users\Lars\mirror
./eclipsec -nosplash -verbose -application org.eclipse.equinox.p2.artifact.repository.mirrorApplication -source https://download.eclipse.org/releases/latest -destination C:\Users\Lars\mirror./eclipse -nosplash -verbose -application org.eclipse.equinox.p2.metadata.repository.mirrorApplication -source https://download.eclipse.org/releases/latest -destination ~/mirror
./eclipse -nosplash -verbose -application org.eclipse.equinox.p2.artifact.repository.mirrorApplication -source https://download.eclipse.org/releases/latest -destination ~/mirror|
This mirroring can run very, very long. But it still can be useful to do this, as you could upload the mirrored artifacts on a server in your network. This will make the target definition resolution most likely faster for your developers. |
After a successful run, you can change your target platform for the platform features to point to the mirrored p2 update site.
7. Learn more and get support
This tutorial continues on Eclipse RCP online training or Eclipse IDE extensions with lots of video material, additional exercises and much more content.
8. Target platform resources
If you need more assistance we offer Online Training and Onsite training as well as consulting