Setting up an embedded server in eclipse.

Part 3: exploring the benefits of a plug-in server

Table of content:
  1. Install eclipse IDE
  2. Creating a web server project
  3. Configuring the project to be a web plugin
  4. Run configuration
  5. Creating another project and mapping it to the web
  6. Adding a javascript framework as a library
  7. Moving library projects out of workspace
  8. Creating a web plug-in without eclipse.

7. Move library projects out of workspace

Workspace is the place to code. Libraries that we use do not change over time and we shouldn't keep them here. We can move our javascript framework outside from our workspace to keep it clean.
This could be done by exporting the project to a jar and putting it to another directory.
Unfortunately, eclipse doesn't allow exporting projects that doesn't have java nature (as our plug-in projects) to a jar in natural way. But jar is just a zip archive and all we need is to put the content there.
Now we have 3 projects mapped to the same server. Let's see the web host (osgi) content. Click Run -> Run Configuration menu. You will see that all workspace projects have been added to the server automatically. We have 3 plug-ins in the workspace and 22 plugins performing web server work.
Current run configuration
Our task is to move the jquery project from the workspace into Target Platform group since it is a library.
Close the dialog. That was just an overview of what plug-ins are used.
Open jquery project location. Select META-INF, web directories, and the plugin.xml file. Then activate right - click menu. Select Export option.
Export project menu In the Export dialog window, choose General - Archive File option. Export dialog - archive type Create a new folder in your disk that will contain web server libraries. It should be empty. You should specify the directory and the file names in the dialog. In my case the directory is D:\droopy\libs and the file name is jquery.jar. Select Create only selected directories option. Then click Finish. Export dialog - archive type and location The library has been created.
Since we have exported the project into another place we can delete it from the workspace. Deleting jquery project from the workspace A warning dialog will appear. Check Delete project contents on disk (cannot be undone), then click OK. Deletion warning dialog Now we should setup the run environment to include the exported jar. Workspace project plug-ins are added automatically but any other plug-in should be added explicitly.
Select Window → Preferences menu. In the dialog, select Plug-in Development → Target Platform. We have our configuration named Running Platform. Select it and click Edit. Target platform selection dialog Click Add button to add another directory which would contains plug-ins. Editing target platform In the Add Content dialog, choose Directory. Adding a directory to Target platform Specify the name of the directory. I use d:\droopy\libs (the directory containing the exported jquery library). New directory name dialog Note eclipse has found that the directory contains the jquery plug-in. Click Finish. Target platform directory content The content of Target Platform configuration has been updated. Updated target platform content Switch to Content tab, then type in "jq" in the filter input. We have found our jquery plug-in. By default, the plug-in was disabled. So we need to check it. Click Finish. Updated target platform content Click Apply, then OK. Updated target platform content Open Run - Run Configuration menu to see the plug-ins that are used by the server host. We should turn on our jquery plug-in. So check it. Updated run configuration Our jquery plugin in included in Target Platform. Whenever we start the server, the plugin would be loaded.
Let's start the server again. On the address http://localhost:8080/second/other.html you will see the jquery plugin is loaded into /jquery url.

8. Creating a web plug-in without eclipse.

Plug-ins don't have to be jar files. A plug-in could be just an unpacked eclipse project. We can use a directory with a similar to project structure to launch it in the web server. We will create a plug-in in the libraries directory (in my case d:/droopy/libs) by hand. I will use Far Manager to show the copying/editing process. In this example I will add dojo framework into our web space.
Create a new directory. Creating a folder for dojo plugin Copy the content of an existing project into it. This time we'll copy the webserver project. We don't need .project and files. Copying a project to new one We should update MANIFEST.MF file of the new plug-in. Change Bundle-Name and Bundle-SymbolicName values to match the description of the plugin. I set the description to "Dojo library" and the plug-in name to "dojo". Editing MANIFEST.MF file Change the alias value in plugin.xml file to the url address the plug-in will be mapped to. Let's use "/dojo" address for this plug-in. Editing plugin.xml file In the web folder was old index.html file. We don't need it so delete it. Copy the content of the dojo framework library into the folder. Copying dojo framework Go back to eclipse.
Every new plug-in created in the Target platform folder isn't added automatically to the OSGi host. We should add this newly created web plug-in to our Target Platform by ourselves. There are two places we should enable it - Target Platform and Run Configuration.
Open Window → Preferences menu. Click Edit. Copying dojo framework We should enable the plugin in the Content tab. Find the dojo plugin and enable it. Click Finish Enabling dojo plugin Click OK Open our run configuration: Run → Run Configurations... menu. Check the dojo plug-in is included. Copying dojo framework

Just remember, after adding a plug-in, enable it at Window → Preferences → Plug-in Development → Target Platform and in Run Configuration. The plugin is disabled by default.

Now we have both jquery and dojo libraries loaded into the web server space. They reside in a separate folder. You can add as many web plug-ins as you want.
Let's check both libraries are loaded into the server space.
	<script type="text/javascript" src="../dojo/dojo/dojo.js"></script>
	<script type="text/javascript">
		require(['dojo/dom', 'dojo/domReady!'], function(dom){
			dom.byId('message').textContent) += ', dojo version is ' + dojo.version;
Then start the server. Adding dojo code to the page Open the browser again at http://localhost:8080/second/other.html A script error on the page Oops, there was an error in our javascript code. Extra right parenthesis in the statement.
We don't have to stop our server to fix the code. Just update the file, then reload the browser page. It will change immediately. The error is fixed Now you can see everything is working. You can stop the server.
That's all. I think you can setup a web server in eclipse now.