Update Bomr to output upgrade links for the release notes

Closes gh-47032

Author: wilkinsona

buildSrc/src/main/java/org/springframework/boot/build/bom/bomr/UpgradeBom.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.build.bom.bomr;
 
+import java.util.List;
+
 import javax.inject.Inject;
 
 import org.gradle.api.Task;
@@ -24,6 +26,7 @@
 import org.gradle.api.artifacts.repositories.MavenArtifactRepository;
 
 import org.springframework.boot.build.bom.BomExtension;
+import org.springframework.boot.build.bom.Library;
 import org.springframework.boot.build.properties.BuildProperties;
 
 /**
@@ -63,4 +66,25 @@ protected String commitMessage(Upgrade upgrade, int issueNumber) {
 		return issueTitle(upgrade) + "\n\nCloses gh-" + issueNumber;
 	}
 
+	@Override
+	protected void upgradesApplied(List<Upgrade> upgrades) {
+		if (upgrades.isEmpty()) {
+			return;
+		}
+		System.out.println();
+		System.out.println("Upgrade release notes:");
+		System.out.println();
+		for (Upgrade upgrade : upgrades) {
+			Library library = upgrade.toRelease();
+			String releaseNotes = library.getLinkUrl("releaseNotes");
+			if (releaseNotes != null) {
+				System.out.println("* " + releaseNotes + "[" + library.getNameAndVersion() + "]");
+			}
+			else {
+				System.out.println("* " + library.getNameAndVersion());
+			}
+		}
+		System.out.println();
+	}
+
 }

buildSrc/src/main/java/org/springframework/boot/build/bom/bomr/UpgradeDependencies.java

@@ -102,6 +102,12 @@ protected UpgradeDependencies(BomExtension bom, boolean movingToSnapshots) {
 	@Option(option = "libraries", description = "Regular expression that identifies the libraries to upgrade")
 	public abstract Property<String> getLibraries();
 
+	@Input
+	@Optional
+	@Option(option = "dry-run-upgrades",
+			description = "Whether to perform a dry run that doesn't open issues or change the bom")
+	public abstract Property<Boolean> getDryRun();
+
 	@Input
 	abstract ListProperty<String> getRepositoryNames();
 
@@ -112,7 +118,14 @@ void upgradeDependencies() {
 		List<String> issueLabels = verifyLabels(repository);
 		Milestone milestone = determineMilestone(repository);
 		List<Upgrade> upgrades = resolveUpgrades(milestone);
-		applyUpgrades(repository, issueLabels, milestone, upgrades);
+		if (!getDryRun().getOrElse(false)) {
+			applyUpgrades(repository, issueLabels, milestone, upgrades);
+		}
+		upgradesApplied(upgrades);
+	}
+
+	protected void upgradesApplied(List<Upgrade> upgrades) {
+
 	}
 
 	private void applyUpgrades(GitHubRepository repository, List<String> issueLabels, Milestone milestone,