[MNG-8054] Ability to force build number

maven-resolver-provider/src/main/java/org/apache/maven/repository/internal/RemoteSnapshotMetadata.java

@@ -44,17 +44,21 @@ final class RemoteSnapshotMetadata extends MavenSnapshotMetadata {
 
     private final Map<String, SnapshotVersion> versions = new LinkedHashMap<>();
 
-    RemoteSnapshotMetadata(Artifact artifact, Date timestamp) {
+    private final Integer buildNumber;
+
+    RemoteSnapshotMetadata(Artifact artifact, Date timestamp, Integer buildNumber) {
         super(createRepositoryMetadata(artifact), null, timestamp);
+        this.buildNumber = buildNumber;
     }
 
-    private RemoteSnapshotMetadata(Metadata metadata, File file, Date timestamp) {
+    private RemoteSnapshotMetadata(Metadata metadata, File file, Date timestamp, Integer buildNumber) {
         super(metadata, file, timestamp);
+        this.buildNumber = buildNumber;
     }
 
     @Override
     public MavenMetadata setFile(File file) {
-        return new RemoteSnapshotMetadata(metadata, file, timestamp);
+        return new RemoteSnapshotMetadata(metadata, file, timestamp, buildNumber);
     }
 
     public String getExpandedVersion(Artifact artifact) {
@@ -73,7 +77,7 @@ protected void merge(Metadata recessive) {
             utcDateFormatter.setTimeZone(DEFAULT_SNAPSHOT_TIME_ZONE);
 
             snapshot = new Snapshot();
-            snapshot.setBuildNumber(getBuildNumber(recessive) + 1);
+            snapshot.setBuildNumber(buildNumber != null ? buildNumber : getBuildNumber(recessive) + 1);
             snapshot.setTimestamp(utcDateFormatter.format(timestamp));
 
             Versioning versioning = new Versioning();

maven-resolver-provider/src/main/java/org/apache/maven/repository/internal/RemoteSnapshotMetadataGenerator.java

@@ -42,8 +42,18 @@ class RemoteSnapshotMetadataGenerator implements MetadataGenerator {
 
     private final Date timestamp;
 
+    private final Integer buildNumber;
+
     RemoteSnapshotMetadataGenerator(RepositorySystemSession session, DeployRequest request) {
         timestamp = (Date) ConfigUtils.getObject(session, new Date(), "maven.startTime");
+        Object bn = ConfigUtils.getObject(session, null, "maven.buildNumber");
+        if (bn instanceof Integer) {
+            this.buildNumber = (Integer) bn;
+        } else if (bn instanceof String) {
+            this.buildNumber = Integer.valueOf((String) bn);
+        } else {
+            this.buildNumber = null;
+        }
 
         snapshots = new LinkedHashMap<>();
 
@@ -68,7 +78,7 @@ public Collection<? extends Metadata> prepare(Collection<? extends Artifact> art
                 Object key = RemoteSnapshotMetadata.getKey(artifact);
                 RemoteSnapshotMetadata snapshotMetadata = snapshots.get(key);
                 if (snapshotMetadata == null) {
-                    snapshotMetadata = new RemoteSnapshotMetadata(artifact, timestamp);
+                    snapshotMetadata = new RemoteSnapshotMetadata(artifact, timestamp, buildNumber);
                     snapshots.put(key, snapshotMetadata);
                 }
                 snapshotMetadata.bind(artifact);

maven-resolver-provider/src/test/java/org/apache/maven/repository/internal/RemoteSnapshotMetadataTest.java

@@ -33,6 +33,7 @@
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 class RemoteSnapshotMetadataTest {
@@ -62,7 +63,8 @@ static String gregorianDate() {
     void gregorianCalendarIsUsed() {
         String dateBefore = gregorianDate();
 
-        RemoteSnapshotMetadata metadata = new RemoteSnapshotMetadata(new DefaultArtifact("a:b:1-SNAPSHOT"), new Date());
+        RemoteSnapshotMetadata metadata =
+                new RemoteSnapshotMetadata(new DefaultArtifact("a:b:1-SNAPSHOT"), new Date(), null);
         metadata.merge(new Metadata());
 
         String dateAfter = gregorianDate();
@@ -74,4 +76,24 @@ void gregorianCalendarIsUsed() {
         Set<String> expected = new HashSet<>(Arrays.asList(dateBefore, dateAfter));
         assertTrue(expected.contains(datePart), "Expected " + datePart + " to be in " + expected);
     }
+
+    @Test
+    void buildNumberNotSet() {
+        RemoteSnapshotMetadata metadata =
+                new RemoteSnapshotMetadata(new DefaultArtifact("a:b:1-SNAPSHOT"), new Date(), null);
+        metadata.merge(new Metadata());
+
+        int buildNumber = metadata.metadata.getVersioning().getSnapshot().getBuildNumber();
+        assertEquals(1, buildNumber);
+    }
+
+    @Test
+    void buildNumberSet() {
+        RemoteSnapshotMetadata metadata =
+                new RemoteSnapshotMetadata(new DefaultArtifact("a:b:1-SNAPSHOT"), new Date(), 42);
+        metadata.merge(new Metadata());
+
+        int buildNumber = metadata.metadata.getVersioning().getSnapshot().getBuildNumber();
+        assertEquals(42, buildNumber);
+    }
 }