Adding a logging resolution event listener

src/main/java/org/openrewrite/maven/MavenLoggingResolutionEventListener.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2024 the original author or authors.
+ *
+ * Licensed 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
+ *
+ * https://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.
+ */
+package org.openrewrite.maven;
+
+import org.apache.maven.plugin.logging.Log;
+import org.openrewrite.internal.lang.Nullable;
+import org.openrewrite.maven.tree.*;
+
+import java.util.List;
+import java.util.Objects;
+
+class MavenLoggingResolutionEventListener implements ResolutionEventListener {
+
+    private final Log logger;
+
+    public MavenLoggingResolutionEventListener(Log logger) {
+        this.logger = Objects.requireNonNull(logger, "logger cannot be null");
+    }
+
+    @Override
+    public void downloadSuccess(ResolvedGroupArtifactVersion gav, @Nullable ResolvedPom containing) {
+        if (logger.isDebugEnabled()) {
+            logger.debug("Downloaded " + gav + pomContaining(containing));
+        }
+    }
+
+    @Override
+    public void downloadError(GroupArtifactVersion gav, List<String> attemptedUris, @Nullable Pom containing) {
+        StringBuilder sb = new StringBuilder("Failed to download " + gav + pomContaining(containing) + ". Attempted URIs:");
+        attemptedUris.forEach(uri -> sb.append("\n  - ").append(uri));
+        logger.error(sb);
+    }
+
+    @Override
+    public void repositoryAccessFailed(String uri, Throwable e) {
+        logger.error("Failed to access maven repository " + uri, e);
+    }
+
+    private static String pomContaining(@Nullable Pom containing) {
+        return containing != null ? " from " + containing.getGav() : "";
+    }
+
+    private static String pomContaining(@Nullable ResolvedPom containing) {
+        return containing != null ? " from " + containing.getGav() : "";
+    }
+}

src/main/java/org/openrewrite/maven/MavenMojoProjectParser.java

@@ -524,6 +524,7 @@ public Map<MavenProject, Xml.Document> parseMaven(List<MavenProject> mavenProjec
         MavenSettings settings = buildSettings();
         MavenExecutionContextView mavenExecutionContext = MavenExecutionContextView.view(ctx);
         mavenExecutionContext.setMavenSettings(settings);
+        mavenExecutionContext.setResolutionListener(new MavenLoggingResolutionEventListener(logger));
 
         if (pomCacheEnabled) {
             //The default pom cache is enabled as a two-layer cache L1 == in-memory and L2 == RocksDb