As recommended opted to use static instance.

Using a static instance also has the benefit of keeping the changes internal. Therefore, no changes to the maven project are required to move to this version.

maven-resolver-demos/maven-resolver-demo-snippets/src/main/java/org/apache/maven/resolver/examples/supplier/SupplierRepositorySystemFactory.java

@@ -35,7 +35,6 @@
 import org.eclipse.aether.spi.artifact.generator.ArtifactGeneratorFactory;
 import org.eclipse.aether.spi.connector.transport.TransporterFactory;
 import org.eclipse.aether.supplier.RepositorySystemSupplier;
-import org.eclipse.aether.transport.jdk.JdkRFC9457Reporter;
 import org.eclipse.aether.transport.jdk.JdkTransporterFactory;
 import org.eclipse.aether.transport.jetty.JettyRFC9457Reporter;
 import org.eclipse.aether.transport.jetty.JettyTransporterFactory;
@@ -96,8 +95,7 @@ protected Map<String, TransporterFactory> createTransporterFactories() {
                 Map<String, TransporterFactory> result = super.createTransporterFactories();
                 result.put(
                         JdkTransporterFactory.NAME,
-                        new JdkTransporterFactory(
-                                getChecksumExtractor(), getPathProcessor(), new JdkRFC9457Reporter()));
+                        new JdkTransporterFactory(getChecksumExtractor(), getPathProcessor()));
                 result.put(
                         JettyTransporterFactory.NAME,
                         new JettyTransporterFactory(

maven-resolver-spi/src/main/java/org/eclipse/aether/spi/connector/transport/http/RFC9457/RFC9457Payload.java

@@ -21,6 +21,8 @@
 import java.net.URI;
 
 public class RFC9457Payload {
+    public static final RFC9457Payload INSTANCE = new RFC9457Payload();
+
     private final URI type;
 
     private final Integer status;
@@ -31,7 +33,7 @@ public class RFC9457Payload {
 
     private final URI instance;
 
-    public RFC9457Payload() {
+    private RFC9457Payload() {
         this(null, null, null, null, null);
     }
 

maven-resolver-spi/src/main/java/org/eclipse/aether/spi/connector/transport/http/RFC9457/RFC9457Reporter.java

@@ -63,14 +63,14 @@ public void generateException(T response, BiConsumerChecked<Integer, String, E>
                 body = getBody(response);
             } catch (IOException ignore) {
                 // No body found but it is representing a RFC 9457 message due to the content type.
-                throw new HttpRFC9457Exception(statusCode, reasonPhrase, new RFC9457Payload());
+                throw new HttpRFC9457Exception(statusCode, reasonPhrase, RFC9457Payload.INSTANCE);
             }
 
             if (body != null && !body.isEmpty()) {
                 RFC9457Payload rfc9457Payload = RFC9457Parser.parse(body);
                 throw new HttpRFC9457Exception(statusCode, reasonPhrase, rfc9457Payload);
             }
-            throw new HttpRFC9457Exception(statusCode, reasonPhrase, new RFC9457Payload());
+            throw new HttpRFC9457Exception(statusCode, reasonPhrase, RFC9457Payload.INSTANCE);
         }
         baseException.accept(statusCode, reasonPhrase);
     }

maven-resolver-supplier-mvn3/src/main/java/org/eclipse/aether/supplier/RepositorySystemSupplier.java

@@ -132,7 +132,6 @@
 import org.eclipse.aether.spi.localrepo.LocalRepositoryManagerFactory;
 import org.eclipse.aether.spi.resolution.ArtifactResolverPostProcessor;
 import org.eclipse.aether.spi.synccontext.SyncContextFactory;
-import org.eclipse.aether.transport.apache.ApacheRFC9457Reporter;
 import org.eclipse.aether.transport.apache.ApacheTransporterFactory;
 import org.eclipse.aether.transport.file.FileTransporterFactory;
 import org.eclipse.aether.util.version.GenericVersionScheme;
@@ -630,19 +629,6 @@ protected ChecksumExtractor createChecksumExtractor() {
         return new DefaultChecksumExtractor(getChecksumExtractorStrategies());
     }
 
-    private ApacheRFC9457Reporter rfc9457Reporter;
-
-    public final ApacheRFC9457Reporter getRfc9457Reporter() {
-        if (rfc9457Reporter == null) {
-            rfc9457Reporter = createRfc9457Reporter();
-        }
-        return rfc9457Reporter;
-    }
-
-    protected ApacheRFC9457Reporter createRfc9457Reporter() {
-        return new ApacheRFC9457Reporter();
-    }
-
     private Map<String, TransporterFactory> transporterFactories;
 
     public final Map<String, TransporterFactory> getTransporterFactories() {
@@ -658,7 +644,7 @@ protected Map<String, TransporterFactory> createTransporterFactories() {
         result.put(FileTransporterFactory.NAME, new FileTransporterFactory());
         result.put(
                 ApacheTransporterFactory.NAME,
-                new ApacheTransporterFactory(getChecksumExtractor(), getPathProcessor(), getRfc9457Reporter()));
+                new ApacheTransporterFactory(getChecksumExtractor(), getPathProcessor()));
         return result;
     }
 

maven-resolver-supplier-mvn4/src/main/java/org/eclipse/aether/supplier/RepositorySystemSupplier.java

@@ -136,7 +136,6 @@
 import org.eclipse.aether.spi.localrepo.LocalRepositoryManagerFactory;
 import org.eclipse.aether.spi.resolution.ArtifactResolverPostProcessor;
 import org.eclipse.aether.spi.synccontext.SyncContextFactory;
-import org.eclipse.aether.transport.apache.ApacheRFC9457Reporter;
 import org.eclipse.aether.transport.apache.ApacheTransporterFactory;
 import org.eclipse.aether.transport.file.FileTransporterFactory;
 import org.eclipse.aether.util.version.GenericVersionScheme;
@@ -634,19 +633,6 @@ protected ChecksumExtractor createChecksumExtractor() {
         return new DefaultChecksumExtractor(getChecksumExtractorStrategies());
     }
 
-    private ApacheRFC9457Reporter rfc9457Reporter;
-
-    public final ApacheRFC9457Reporter getRfc9457Reporter() {
-        if (rfc9457Reporter == null) {
-            rfc9457Reporter = createRfc9457Reporter();
-        }
-        return rfc9457Reporter;
-    }
-
-    protected ApacheRFC9457Reporter createRfc9457Reporter() {
-        return new ApacheRFC9457Reporter();
-    }
-
     private Map<String, TransporterFactory> transporterFactories;
 
     public final Map<String, TransporterFactory> getTransporterFactories() {
@@ -662,7 +648,7 @@ protected Map<String, TransporterFactory> createTransporterFactories() {
         result.put(FileTransporterFactory.NAME, new FileTransporterFactory());
         result.put(
                 ApacheTransporterFactory.NAME,
-                new ApacheTransporterFactory(getChecksumExtractor(), getPathProcessor(), getRfc9457Reporter()));
+                new ApacheTransporterFactory(getChecksumExtractor(), getPathProcessor()));
         return result;
     }
 

maven-resolver-transport-apache/src/main/java/org/eclipse/aether/transport/apache/ApacheRFC9457Reporter.java

@@ -29,6 +29,10 @@
 import org.eclipse.aether.spi.connector.transport.http.RFC9457.RFC9457Reporter;
 
 public class ApacheRFC9457Reporter extends RFC9457Reporter<CloseableHttpResponse, HttpResponseException> {
+    public static final ApacheRFC9457Reporter INSTANCE = new ApacheRFC9457Reporter();
+
+    private ApacheRFC9457Reporter() {}
+
     @Override
     protected boolean isRFC9457Message(final CloseableHttpResponse response) {
         Header[] headers = response.getHeaders(HttpHeaders.CONTENT_TYPE);

maven-resolver-transport-apache/src/main/java/org/eclipse/aether/transport/apache/ApacheTransporter.java

@@ -145,20 +145,16 @@ final class ApacheTransporter extends AbstractTransporter implements HttpTranspo
 
     private final boolean supportWebDav;
 
-    private final ApacheRFC9457Reporter rfc9457Reporter;
-
     @SuppressWarnings("checkstyle:methodlength")
     ApacheTransporter(
             RemoteRepository repository,
             RepositorySystemSession session,
             ChecksumExtractor checksumExtractor,
-            PathProcessor pathProcessor,
-            ApacheRFC9457Reporter rfc9457Reporter)
+            PathProcessor pathProcessor)
             throws NoTransporterException {
         if (!"http".equalsIgnoreCase(repository.getProtocol()) && !"https".equalsIgnoreCase(repository.getProtocol())) {
             throw new NoTransporterException(repository);
         }
-        this.rfc9457Reporter = rfc9457Reporter;
         this.checksumExtractor = checksumExtractor;
         this.pathProcessor = pathProcessor;
         try {
@@ -610,7 +606,7 @@ private <T extends HttpUriRequest> void resume(T request, GetTask task) throws I
     private void handleStatus(CloseableHttpResponse response) throws Exception {
         int status = response.getStatusLine().getStatusCode();
         if (status >= 300) {
-            rfc9457Reporter.generateException(response, (statusCode, reasonPhrase) -> {
+            ApacheRFC9457Reporter.INSTANCE.generateException(response, (statusCode, reasonPhrase) -> {
                 throw new HttpResponseException(statusCode, reasonPhrase + " (" + statusCode + ")");
             });
         }

maven-resolver-transport-apache/src/main/java/org/eclipse/aether/transport/apache/ApacheTransporterFactory.java

@@ -39,19 +39,15 @@
 public final class ApacheTransporterFactory implements HttpTransporterFactory {
     public static final String NAME = "apache";
 
-    private final ApacheRFC9457Reporter rfc9457Reporter;
-
     private float priority = 5.0f;
 
     private final ChecksumExtractor checksumExtractor;
 
     private final PathProcessor pathProcessor;
 
     @Inject
-    public ApacheTransporterFactory(
-            ChecksumExtractor checksumExtractor, PathProcessor pathProcessor, ApacheRFC9457Reporter rfc9457Reporter) {
+    public ApacheTransporterFactory(ChecksumExtractor checksumExtractor, PathProcessor pathProcessor) {
         this.checksumExtractor = requireNonNull(checksumExtractor, "checksumExtractor");
-        this.rfc9457Reporter = requireNonNull(rfc9457Reporter, "rfc9457Reporter");
         this.pathProcessor = requireNonNull(pathProcessor, "pathProcessor");
     }
 
@@ -77,6 +73,6 @@ public HttpTransporter newInstance(RepositorySystemSession session, RemoteReposi
         requireNonNull(session, "session cannot be null");
         requireNonNull(repository, "repository cannot be null");
 
-        return new ApacheTransporter(repository, session, checksumExtractor, pathProcessor, rfc9457Reporter);
+        return new ApacheTransporter(repository, session, checksumExtractor, pathProcessor);
     }
 }

maven-resolver-transport-apache/src/test/java/org/eclipse/aether/transport/apache/ApacheTransporterTest.java

@@ -44,8 +44,7 @@
 class ApacheTransporterTest extends HttpTransporterTest {
 
     public ApacheTransporterTest() {
-        super(() -> new ApacheTransporterFactory(
-                standardChecksumExtractor(), new TestPathProcessor(), new ApacheRFC9457Reporter()));
+        super(() -> new ApacheTransporterFactory(standardChecksumExtractor(), new TestPathProcessor()));
     }
 
     @Override

maven-resolver-transport-jdk-parent/maven-resolver-transport-jdk-11/src/main/java/org/eclipse/aether/transport/jdk/JdkRFC9457Reporter.java

@@ -28,6 +28,10 @@
 import org.eclipse.aether.spi.connector.transport.http.RFC9457.RFC9457Reporter;
 
 public class JdkRFC9457Reporter extends RFC9457Reporter<HttpResponse<InputStream>, HttpTransporterException> {
+    public static final JdkRFC9457Reporter INSTANCE = new JdkRFC9457Reporter();
+
+    private JdkRFC9457Reporter() {}
+
     @Override
     protected boolean isRFC9457Message(final HttpResponse<InputStream> response) {
         Optional<String> optionalContentType = response.headers().firstValue("Content-Type");

maven-resolver-transport-jdk-parent/maven-resolver-transport-jdk-11/src/main/java/org/eclipse/aether/transport/jdk/JdkTransporter.java

@@ -116,8 +116,6 @@ final class JdkTransporter extends AbstractTransporter implements HttpTransporte
 
     private final PathProcessor pathProcessor;
 
-    private final JdkRFC9457Reporter rfc9457Reporter;
-
     private final URI baseUri;
 
     private final HttpClient client;
@@ -135,11 +133,9 @@ final class JdkTransporter extends AbstractTransporter implements HttpTransporte
             RemoteRepository repository,
             int javaVersion,
             ChecksumExtractor checksumExtractor,
-            PathProcessor pathProcessor,
-            JdkRFC9457Reporter rfc9457Reporter)
+            PathProcessor pathProcessor)
             throws NoTransporterException {
         this.checksumExtractor = checksumExtractor;
-        this.rfc9457Reporter = rfc9457Reporter;
         this.pathProcessor = pathProcessor;
         try {
             URI uri = new URI(repository.getUrl()).parseServerAuthority();
@@ -295,7 +291,7 @@ protected void implGet(GetTask task) throws Exception {
                             continue;
                         }
                         try {
-                            rfc9457Reporter.generateException(response, (statusCode, reasonPhrase) -> {
+                            JdkRFC9457Reporter.INSTANCE.generateException(response, (statusCode, reasonPhrase) -> {
                                 throw new HttpTransporterException(statusCode);
                             });
                         } finally {

maven-resolver-transport-jdk-parent/maven-resolver-transport-jdk-11/src/main/java/org/eclipse/aether/transport/jdk/JdkTransporterFactory.java

@@ -40,20 +40,16 @@
 public final class JdkTransporterFactory implements HttpTransporterFactory {
     public static final String NAME = "jdk";
 
-    private final JdkRFC9457Reporter rfc9457Reporter;
-
     private float priority = 10.0f;
 
     private final ChecksumExtractor checksumExtractor;
 
     private final PathProcessor pathProcessor;
 
     @Inject
-    public JdkTransporterFactory(
-            ChecksumExtractor checksumExtractor, PathProcessor pathProcessor, JdkRFC9457Reporter rfc9457Reporter) {
+    public JdkTransporterFactory(ChecksumExtractor checksumExtractor, PathProcessor pathProcessor) {
         this.checksumExtractor = requireNonNull(checksumExtractor, "checksumExtractor");
         this.pathProcessor = requireNonNull(pathProcessor, "pathProcessor");
-        this.rfc9457Reporter = requireNonNull(rfc9457Reporter, "RFC9457Reporter");
     }
 
     @Override
@@ -76,8 +72,7 @@ public HttpTransporter newInstance(RepositorySystemSession session, RemoteReposi
             throw new NoTransporterException(repository, "Only HTTP/HTTPS is supported");
         }
 
-        return new JdkTransporter(
-                session, repository, javaVersion(), checksumExtractor, pathProcessor, rfc9457Reporter);
+        return new JdkTransporter(session, repository, javaVersion(), checksumExtractor, pathProcessor);
     }
 
     private static int javaVersion() {

maven-resolver-transport-jdk-parent/maven-resolver-transport-jdk-11/src/test/java/org/eclipse/aether/transport/jdk/JdkTransporterTest.java

@@ -85,16 +85,14 @@ protected void testRetryHandler_explicitCount_positive() {}
     protected void testPut_Authenticated_ExpectContinueRejected_ExplicitlyConfiguredHeader() {}
 
     public JdkTransporterTest() {
-        super(() -> new JdkTransporterFactory(
-                standardChecksumExtractor(), new DefaultPathProcessor(), new JdkRFC9457Reporter()));
+        super(() -> new JdkTransporterFactory(standardChecksumExtractor(), new DefaultPathProcessor()));
     }
 
     @Test
     void enhanceConnectExceptionMessages() {
         String uri = "https://localhost:12345/";
         RemoteRepository remoteRepository = new RemoteRepository.Builder("central", "default", uri).build();
-        JdkTransporterFactory factory =
-                new JdkTransporterFactory(s -> null, new DefaultPathProcessor(), new JdkRFC9457Reporter());
+        JdkTransporterFactory factory = new JdkTransporterFactory(s -> null, new DefaultPathProcessor());
 
         try (Transporter transporter = factory.newInstance(TestUtils.newSession(), remoteRepository)) {
             transporter.peek(new PeekTask(URI.create("repo/file.txt")));

maven-resolver-transport-jdk-parent/maven-resolver-transport-jdk-8/src/main/java/org/eclipse/aether/transport/jdk/JdkRFC9457Reporter.java

@@ -28,6 +28,10 @@
 import org.eclipse.aether.spi.connector.transport.http.RFC9457.RFC9457Reporter;
 
 public class JdkRFC9457Reporter extends RFC9457Reporter<HttpURLConnection, HttpTransporterException> {
+    public static final JdkRFC9457Reporter INSTANCE = new JdkRFC9457Reporter();
+
+    private JdkRFC9457Reporter() {}
+
     @Override
     protected boolean isRFC9457Message(final HttpURLConnection response) {
         String contentType = response.getContentType();
@@ -50,8 +54,8 @@ protected String getReasonPhrase(final HttpURLConnection response) {
 
     @Override
     protected String getBody(final HttpURLConnection response) throws IOException {
-        try (BufferedReader br = new BufferedReader(new InputStreamReader(response.getInputStream(),
-            StandardCharsets.UTF_8))) {
+        try (BufferedReader br =
+                new BufferedReader(new InputStreamReader(response.getInputStream(), StandardCharsets.UTF_8))) {
             StringBuilder sb = new StringBuilder();
             String line;
             while ((line = br.readLine()) != null) {

maven-resolver-transport-jetty/src/test/java/org/eclipse/aether/transport/jetty/JettyTransporterTest.java

@@ -60,6 +60,6 @@ protected void testPut_Authenticated_ExpectContinueRejected_ExplicitlyConfigured
 
     public JettyTransporterTest() {
         super(() -> new JettyTransporterFactory(
-                standardChecksumExtractor(), new TestPathProcessor(), new JettyRFC9457Reporter()));
+                standardChecksumExtractor(), new TestPathProcessor(), JettyRFC9457Reporter.INSTANCE));
     }
 }