Issue 546

org.eclipse.m2e.core/plugin.xml

@@ -134,5 +134,15 @@
             class="org.eclipse.m2e.core.internal.project.WorkspaceTestsClassifierResolver">
       </resolver>
    </extension>
+   <extension
+         point="org.eclipse.core.runtime.adapters">
+      <factory
+            adaptableType="org.eclipse.core.resources.IResource"
+            class="org.eclipse.m2e.core.internal.project.registry.ProjectFacadeAdapterFactory">
+         <adapter
+               type="org.eclipse.m2e.core.project.IMavenProjectFacade">
+         </adapter>
+      </factory>
+   </extension>
 
 </plugin>

org.eclipse.m2e.core/src/org/eclipse/m2e/core/MavenPlugin.java

@@ -18,6 +18,7 @@
 import org.eclipse.m2e.core.embedder.MavenModelManager;
 import org.eclipse.m2e.core.embedder.MavenRuntimeManager;
 import org.eclipse.m2e.core.internal.MavenPluginActivator;
+import org.eclipse.m2e.core.project.IMavenProjectFacade;
 import org.eclipse.m2e.core.project.IMavenProjectRegistry;
 import org.eclipse.m2e.core.project.IProjectConfigurationManager;
 import org.eclipse.m2e.core.project.IWorkspaceClassifierResolverManager;
@@ -41,6 +42,11 @@ public static MavenPlugin getDefault() {
     return INSTANCE;
   }
 
+  /**
+   * Use {@link IMavenProjectFacade#getMaven()} instead whenever possible
+   * 
+   * @return a generic Maven instance (not customized by project).
+   */
   public static IMaven getMaven() {
     return MavenPluginActivator.getDefault().getMaven();
   }

org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/project/registry/MavenProjectFacade.java

@@ -36,6 +36,7 @@
 import org.apache.maven.plugin.MojoExecution;
 import org.apache.maven.project.MavenProject;
 
+import org.eclipse.m2e.core.MavenPlugin;
 import org.eclipse.m2e.core.embedder.ArtifactKey;
 import org.eclipse.m2e.core.embedder.ArtifactRef;
 import org.eclipse.m2e.core.embedder.ArtifactRepositoryRef;
@@ -528,4 +529,10 @@ public List<MojoExecution> getExecutionPlan(String lifecycle, IProgressMonitor m
     Map<String, List<MojoExecution>> executionPlans = getExecutionPlans(monitor);
     return executionPlans != null ? executionPlans.get(lifecycle) : null;
   }
+
+  @Override
+  public IMaven getMaven() {
+    // TODO: if project has Maven customization (such as a .mvn, MAVEN_OPTS...)
+    return MavenPlugin.getMaven();
+  }
 }

org.eclipse.m2e.core/src/org/eclipse/m2e/core/internal/project/registry/ProjectFacadeAdapterFactory.java

@@ -0,0 +1,35 @@
+/*******************************************************************************
+ * Copyright (c) 2022 Red Hat, Inc.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *******************************************************************************/
+package org.eclipse.m2e.core.internal.project.registry;
+
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.runtime.IAdapterFactory;
+
+import org.eclipse.m2e.core.MavenPlugin;
+import org.eclipse.m2e.core.project.IMavenProjectFacade;
+
+public class ProjectFacadeAdapterFactory implements IAdapterFactory {
+
+  private static final Class<?>[] ADAPTER_LIST = {IMavenProjectFacade.class};
+
+  @Override
+  public <T> T getAdapter(Object adaptableObject, Class<T> adapterType) {
+    if(adaptableObject instanceof IResource && adapterType == IMavenProjectFacade.class) {
+      return (T) MavenPlugin.getMavenProjectRegistry().getProject(((IResource) adaptableObject).getProject());
+    }
+    return null;
+  }
+
+  @Override
+  public Class<?>[] getAdapterList() {
+    return ADAPTER_LIST;
+  }
+
+}

org.eclipse.m2e.core/src/org/eclipse/m2e/core/project/IMavenProjectFacade.java

@@ -30,6 +30,7 @@
 import org.eclipse.m2e.core.embedder.ArtifactKey;
 import org.eclipse.m2e.core.embedder.ArtifactRef;
 import org.eclipse.m2e.core.embedder.ArtifactRepositoryRef;
+import org.eclipse.m2e.core.embedder.IMaven;
 import org.eclipse.m2e.core.lifecyclemapping.model.IPluginExecutionMetadata;
 import org.eclipse.m2e.core.project.configurator.MojoExecutionKey;
 
@@ -137,6 +138,13 @@ public interface IMavenProjectFacade {
 
   Set<ArtifactRepositoryRef> getPluginArtifactRepositoryRefs();
 
+  /**
+   * Gets an access to a Maven instance, configured according to this project.
+   * 
+   * @return a Maven instance, configured according to this project
+   */
+  IMaven getMaven();
+
   /**
    * Returns fully setup MojoExecution instance bound to project build lifecycle that matches provided mojoExecutionKey.
    * Returns null if no such mojo execution.
@@ -156,4 +164,5 @@ List<MojoExecution> getMojoExecutions(String groupId, String artifactId, IProgre
   String getLifecycleMappingId();
 
   Map<MojoExecutionKey, List<IPluginExecutionMetadata>> getMojoExecutionMapping();
+
 }

org.eclipse.m2e.core/src/org/eclipse/m2e/core/project/IMavenProjectRegistry.java

@@ -73,6 +73,8 @@ public interface IMavenProjectRegistry {
   IMavenProjectFacade[] getProjects();
 
   /**
+   * You can also use <code>Adapters.adapt(resource, IMavenProjectFacade.class)</code>.
+   * 
    * @return IMavenProjectFacade cached IMavenProjectFacade corresponding to the project or null if there is no cache
    *         entry for the project.
    */