Register the maven protocol handler as a DS component

Author: laeubi

org.eclipse.m2e.core/META-INF/MANIFEST.MF

@@ -58,6 +58,7 @@ Import-Package: com.google.common.base;version="30.1.0",
  org.slf4j;version="[1.7.0,3.0.0)"
 Automatic-Module-Name: org.eclipse.m2e.core
 Service-Component: OSGI-INF/org.eclipse.m2e.core.embedder.MavenModelManager.xml,
+ OSGI-INF/org.eclipse.m2e.core.internal.MvnProtocolHandlerService.xml,
  OSGI-INF/org.eclipse.m2e.core.internal.embedder.EclipseLoggerManager.xml,
  OSGI-INF/org.eclipse.m2e.core.internal.embedder.MavenImpl.xml,
  OSGI-INF/org.eclipse.m2e.core.internal.embedder.PlexusContainerManager.xml,

org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/MavenPluginActivator.java

@@ -23,10 +23,7 @@
 import org.osgi.framework.BundleListener;
 import org.osgi.framework.Constants;
 import org.osgi.framework.FrameworkUtil;
-import org.osgi.framework.ServiceRegistration;
 import org.osgi.framework.Version;
-import org.osgi.service.url.URLConstants;
-import org.osgi.service.url.URLStreamHandlerService;
 import org.osgi.util.tracker.ServiceTracker;
 
 import org.eclipse.aether.RepositorySystem;
@@ -66,8 +63,6 @@ public class MavenPluginActivator extends Plugin {
 
   private final BundleListener bundleListener = event -> LifecycleMappingFactory.setBundleMetadataSources(null);
 
-  private ServiceRegistration<URLStreamHandlerService> protocolHandlerService;
-
   private Map<Class<?>, ServiceTracker<?, ?>> trackers = new ConcurrentHashMap<>();
 
   public IMaven getMaven() {
@@ -110,11 +105,6 @@ public void start(final BundleContext context) throws Exception {
     URLConnectionCaches.disable();
     // For static access, this also enables any of the services and keep them running forever...
     this.bundleContext = context;
-    //register URL handler, we can't use DS here because this triggers loading of m2e too early
-    Map<String, Object> properties = Map.of(URLConstants.URL_HANDLER_PROTOCOL, new String[] {"mvn"});
-    this.protocolHandlerService = context.registerService(URLStreamHandlerService.class,
-        new MvnProtocolHandlerService(), FrameworkUtil.asDictionary(properties));
-
   }
 
   /**
@@ -123,9 +113,6 @@ public void start(final BundleContext context) throws Exception {
   @Override
   public void stop(BundleContext context) throws Exception {
     super.stop(context);
-    if(protocolHandlerService != null) {
-      protocolHandlerService.unregister();
-    }
     context.removeBundleListener(bundleListener);
 
     toDisposeContainers.forEach(PlexusContainer::dispose);

org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/MvnProtocolHandlerService.java

@@ -22,7 +22,11 @@
 import java.net.URLConnection;
 import java.util.List;
 
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Reference;
 import org.osgi.service.url.AbstractURLStreamHandlerService;
+import org.osgi.service.url.URLConstants;
+import org.osgi.service.url.URLStreamHandlerService;
 
 import org.eclipse.aether.RepositorySystem;
 import org.eclipse.aether.RepositorySystemSession;
@@ -40,21 +44,24 @@
 import org.apache.maven.RepositoryUtils;
 import org.apache.maven.artifact.repository.ArtifactRepository;
 
-import org.eclipse.m2e.core.MavenPlugin;
 import org.eclipse.m2e.core.embedder.ICallable;
 import org.eclipse.m2e.core.embedder.IMaven;
 import org.eclipse.m2e.core.embedder.IMavenExecutionContext;
 
 
-//@Component(service = URLStreamHandlerService.class, property = URLConstants.URL_HANDLER_PROTOCOL + "=mvn", immediate = true)
+@Component(service = URLStreamHandlerService.class, property = URLConstants.URL_HANDLER_PROTOCOL + "=mvn")
 public class MvnProtocolHandlerService extends AbstractURLStreamHandlerService {
 
-  public MvnProtocolHandlerService() {
-  }
+  @Reference
+  IMaven maven;
 
   @Override
   public URLConnection openConnection(URL url) {
-    return new MavenURLConnection(url);
+    //TODO replace reference with IMaven maven = MavenPlugin.getMaven();
+    //this is required to make the component active even if m2e itself is not running at the moment
+    //that will make the m2e protocol available from the start of eclipse
+    //See https://github.com/eclipse-equinox/equinox/pull/290
+    return new MavenURLConnection(url, maven);
   }
 
   private static final class MavenURLConnection extends URLConnection {
@@ -63,8 +70,11 @@ private static final class MavenURLConnection extends URLConnection {
 
     private ArtifactResult artifactResult;
 
-    protected MavenURLConnection(URL url) {
+    private IMaven maven;
+
+    protected MavenURLConnection(URL url, IMaven maven) {
       super(url);
+      this.maven = maven;
     }
 
     @Override
@@ -92,9 +102,7 @@ public void connect() throws IOException {
       String classifier = coordinates.length > 4 ? coordinates[4] : null;
       Artifact artifact = new DefaultArtifact(coordinates[0], coordinates[1], classifier, type, coordinates[2]);
       try {
-        IMaven maven = MavenPlugin.getMaven();
-        RepositorySystem repoSystem = org.eclipse.m2e.core.internal.MavenPluginActivator.getDefault()
-            .getRepositorySystem();
+        RepositorySystem repoSystem = maven.lookup(RepositorySystem.class);
         IMavenExecutionContext context = maven.createExecutionContext();
         List<ArtifactRepository> artifactRepositories = maven.getArtifactRepositories();
         List<RemoteRepository> remoteRepositories = RepositoryUtils.toRepos(artifactRepositories);