[MDEP-425] - Add list-plugin-repositories goal

src/it/projects/list-plugin-repositories/invoker.properties

@@ -0,0 +1,18 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+# 
+#   http://www.apache.org/licenses/LICENSE-2.0
+# 
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+invoker.goals = ${project.groupId}:${project.artifactId}:${project.version}:list-plugin-repositories

src/it/projects/list-plugin-repositories/pom.xml

@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Licensed to the Apache Software Foundation (ASF) under one
+  ~ or more contributor license agreements.  See the NOTICE file
+  ~ distributed with this work for additional information
+  ~ regarding copyright ownership.  The ASF licenses this file
+  ~ to you under the Apache License, Version 2.0 (the
+  ~ "License"); you may not use this file except in compliance
+  ~ with the License.  You may obtain a copy of the License at
+  ~
+  ~   http://www.apache.org/licenses/LICENSE-2.0
+  ~
+  ~ Unless required by applicable law or agreed to in writing,
+  ~ software distributed under the License is distributed on an
+  ~ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+  ~ KIND, either express or implied.  See the License for the
+  ~ specific language governing permissions and limitations
+  ~ under the License.
+  -->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>org.apache.maven.its.dependency</groupId>
+  <artifactId>test</artifactId>
+  <version>1.0-SNAPSHOT</version>
+
+  <name>Test</name>
+  <description>
+    Test dependency:list-plugin-repositories
+  </description>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>org.apache.maven</groupId>
+      <artifactId>maven-project</artifactId>
+      <version>2.0.6</version>
+    </dependency>
+  </dependencies>
+
+</project>

src/main/java/org/apache/maven/plugins/dependency/resolvers/ListPluginRepositoriesMojo.java

@@ -0,0 +1,66 @@
+package org.apache.maven.plugins.dependency.resolvers;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import java.util.List;
+
+import org.apache.maven.artifact.repository.ArtifactRepository;
+import org.apache.maven.plugin.MojoExecutionException;
+import org.apache.maven.plugins.annotations.Mojo;
+import org.apache.maven.plugins.annotations.Parameter;
+import org.apache.maven.shared.artifact.filter.collection.ArtifactsFilter;
+
+/**
+ * Goal that resolves all project plugins and then lists the plugin
+ * repositories used by the build and by the transitive plugins
+ *
+ * @since 3.2
+ */
+@Mojo( name = "list-plugin-repositories", threadSafe = true )
+public class ListPluginRepositoriesMojo
+    extends AbstractResolveMojo
+{
+
+    @Parameter( defaultValue = "${project.pluginArtifactRepositories}", readonly = true, required = true )
+    private List<ArtifactRepository> remotePluginRepositories;
+
+    /**
+     * Displays a list of the plugin repositories used by this build.
+     *
+     * @throws MojoExecutionException with a message if an error occurs.
+     */
+    @Override
+    protected void doExecute()
+        throws MojoExecutionException
+    {
+        this.getLog().info( "Plugin repositories used by this build:" );
+
+        for ( ArtifactRepository repo : remotePluginRepositories )
+        {
+            this.getLog().info( repo.toString() );
+        }
+    }
+
+    @Override
+    protected ArtifactsFilter getMarkedArtifactFilter()
+    {
+        return null;
+    }
+}