Unify on Map.of

5 files changed, 10 insertions, 14 deletions

diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/StaticConfigDefinitionRepo.java b/configserver/src/main/java/com/yahoo/vespa/config/server/StaticConfigDefinitionRepo.java
index 51918b4902a..bfad5af504c 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/StaticConfigDefinitionRepo.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/StaticConfigDefinitionRepo.java
@@ -6,7 +6,6 @@ import com.yahoo.config.model.api.ConfigDefinitionRepo;
 import com.yahoo.vespa.config.ConfigDefinitionKey;
 import com.yahoo.vespa.config.buildergen.ConfigDefinition;
 
-import java.util.Collections;
 import java.util.Map;
 
 /**
@@ -24,7 +23,7 @@ public class StaticConfigDefinitionRepo implements ConfigDefinitionRepo {
         this.repo = new ConfigDefinitionRepo() {
             @Override
             public Map<ConfigDefinitionKey, ConfigDefinition> getConfigDefinitions() {
-                return Collections.emptyMap();
+                return Map.of();
             }
 
             @Override
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/application/FileDistributionStatus.java b/configserver/src/main/java/com/yahoo/vespa/config/server/application/FileDistributionStatus.java
index 3de35a20008..57ecd175435 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/application/FileDistributionStatus.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/application/FileDistributionStatus.java
@@ -16,7 +16,6 @@ import com.yahoo.vespa.config.server.http.JSONResponse;
 
 import java.time.Duration;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -75,7 +74,7 @@ public class FileDistributionStatus extends AbstractComponent {
         if (request.isError()) {
             return new HostStatus(hostname,
                                   Status.UNKNOWN,
-                                  Collections.emptyMap(),
+                                  Map.of(),
                                   "error: " + request.errorMessage() + "(" + request.errorCode() + ")");
         } else {
             Map<String, Double> fileReferenceStatuses = new HashMap<>();
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/rpc/RpcServer.java b/configserver/src/main/java/com/yahoo/vespa/config/server/rpc/RpcServer.java
index b0ecedd4853..6d671377e63 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/rpc/RpcServer.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/rpc/RpcServer.java
@@ -48,7 +48,6 @@ import com.yahoo.vespa.filedistribution.FileReferenceDownload;
 import java.nio.ByteBuffer;
 import java.time.Duration;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -131,7 +130,7 @@ public class RpcServer implements Runnable, ConfigActivationListener, TenantList
         this.superModelRequestHandler = superModelRequestHandler;
         metricUpdaterFactory = metrics;
         supervisor.setMaxOutputBufferSize(config.maxoutputbuffersize());
-        this.metrics = metrics.getOrCreateMetricUpdater(Collections.emptyMap());
+        this.metrics = metrics.getOrCreateMetricUpdater(Map.of());
         BlockingQueue<Runnable> workQueue = new LinkedBlockingQueue<>(config.maxgetconfigclients());
         int rpcWorkerThreads = (config.numRpcThreads() == 0) ? threadsToUse() : config.numRpcThreads();
         executorService = new ThreadPoolExecutor(rpcWorkerThreads, rpcWorkerThreads,
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/TenantRepository.java b/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/TenantRepository.java
index 8c4445f897c..f9f477c9693 100644
--- a/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/TenantRepository.java
+++ b/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/TenantRepository.java
@@ -194,7 +194,7 @@ public class TenantRepository {
         this.configserverConfig = configserverConfig;
         this.curator = curator;
         this.metrics = metrics;
-        metricUpdater = metrics.getOrCreateMetricUpdater(Collections.emptyMap());
+        metricUpdater = metrics.getOrCreateMetricUpdater(Map.of());
         this.zkCacheExecutor = zkCacheExecutor;
         this.zkApplicationWatcherExecutor = zkApplicationWatcherExecutor;
         this.zkSessionWatcherExecutor = zkSessionWatcherExecutor;
@@ -312,7 +312,7 @@ public class TenantRepository {
             }
         }
 
-        if (failed.size() > 0)
+        if (!failed.isEmpty())
             throw new RuntimeException("Could not create all tenants when bootstrapping, failed to create: " + failed);
 
         metricUpdater.setTenants(tenants.size());
diff --git a/configserver/src/test/java/com/yahoo/vespa/config/server/http/v2/SessionCreateHandlerTest.java b/configserver/src/test/java/com/yahoo/vespa/config/server/http/v2/SessionCreateHandlerTest.java
index b8c9a2f8fb8..4fb514bde17 100644
--- a/configserver/src/test/java/com/yahoo/vespa/config/server/http/v2/SessionCreateHandlerTest.java
+++ b/configserver/src/test/java/com/yahoo/vespa/config/server/http/v2/SessionCreateHandlerTest.java
@@ -30,7 +30,6 @@ import java.io.FileWriter;
 import java.io.IOException;
 import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -93,7 +92,7 @@ public class SessionCreateHandlerTest extends SessionHandlerTest {
     @Ignore
     @Test
     public void require_that_from_parameter_cannot_be_set_if_data_in_request() throws IOException {
-        HttpRequest request = post(Collections.singletonMap("from", "active"));
+        HttpRequest request = post(Map.of("from", "active"));
         HttpResponse response = createHandler().handle(request);
         assertHttpStatusCodeErrorCodeAndMessage(response, BAD_REQUEST, HttpErrorResponse.ErrorCode.BAD_REQUEST, "Parameter 'from' is illegal for POST");
     }
@@ -114,14 +113,14 @@ public class SessionCreateHandlerTest extends SessionHandlerTest {
 
     private void assertIllegalFromParameter(String fromValue) throws IOException {
         File outFile = CompressedApplicationInputStreamTest.createTarFile(temporaryFolder.getRoot().toPath());
-        HttpRequest request = post(outFile, postHeaders, Collections.singletonMap("from", fromValue));
+        HttpRequest request = post(outFile, postHeaders, Map.of("from", fromValue));
         assertHttpStatusCodeErrorCodeAndMessage(createHandler().handle(request), BAD_REQUEST, HttpErrorResponse.ErrorCode.BAD_REQUEST, "Parameter 'from' has illegal value '" + fromValue + "'");
     }
 
     @Test
     public void require_that_prepare_url_is_returned_on_success() throws IOException {
         File outFile = CompressedApplicationInputStreamTest.createTarFile(temporaryFolder.getRoot().toPath());
-        Map<String, String> parameters = Collections.singletonMap("name", "foo");
+        Map<String, String> parameters = Map.of("name", "foo");
         HttpResponse response = createHandler().handle(post(outFile, postHeaders, parameters));
         assertNotNull(response);
         assertEquals(OK, response.getStatus());
@@ -160,7 +159,7 @@ public class SessionCreateHandlerTest extends SessionHandlerTest {
     @Test
     public void require_that_application_urls_can_be_given_as_from_parameter() throws Exception {
         ApplicationId applicationId = ApplicationId.from(tenant.value(), "foo", "quux");
-        HttpRequest request = post(Collections.singletonMap(
+        HttpRequest request = post(Map.of(
                 "from",
                 "http://myhost:40555/application/v2/tenant/" + tenant + "/application/foo/environment/test/region/baz/instance/quux"));
         assertEquals(applicationId, SessionCreateHandler.getFromApplicationId(request));
@@ -180,7 +179,7 @@ public class SessionCreateHandlerTest extends SessionHandlerTest {
     public void require_that_content_type_is_parsed_correctly() throws FileNotFoundException {
         HttpRequest request = post(new ByteArrayInputStream("foo".getBytes(StandardCharsets.UTF_8)),
                                    Map.of("Content-Type", "multipart/form-data; charset=ISO-8859-1; boundary=g5gJAzUWl_t6"),
-                                   Collections.emptyMap());
+                                   Map.of());
 
         // Valid header should validate ok
         SessionCreateHandler.validateDataAndHeader(request, List.of(ContentType.MULTIPART_FORM_DATA.getMimeType()));