refactor(http-client-java): consolidate TypeSpec mappers into base mappers

.chronus/changes/http-client-java-consolidate-mappers-2026-6-24.md

@@ -0,0 +1,8 @@
+---
+changeKind: internal
+packages:
+  - "@typespec/http-client-java"
+---
+
+Simplify the mapper class hierarchy by consolidating the TypeSpec-specific mappers into
+the shared base mappers.

packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/mapper/ClientMapper.java

@@ -49,6 +49,7 @@
 import com.microsoft.typespec.http.client.generator.core.template.Templates;
 import com.microsoft.typespec.http.client.generator.core.util.ClientModelUtil;
 import com.microsoft.typespec.http.client.generator.core.util.CodeNamer;
+import com.microsoft.typespec.http.client.generator.core.util.ModelUtil;
 import com.microsoft.typespec.http.client.generator.core.util.SchemaUtil;
 import io.clientcore.core.utils.CoreUtils;
 import java.util.ArrayList;
@@ -481,7 +482,16 @@ private void addProtocolExamples(Client.Builder builder, List<AsyncSyncClient> s
     protected Map<ServiceClient, com.microsoft.typespec.http.client.generator.core.extension.model.codemodel.Client>
         processClients(List<com.microsoft.typespec.http.client.generator.core.extension.model.codemodel.Client> clients,
             CodeModel codeModel) {
-        return Map.of();
+        Map<ServiceClient, com.microsoft.typespec.http.client.generator.core.extension.model.codemodel.Client> serviceClientsMap
+            = new LinkedHashMap<>();
+        ServiceClientMapper mapper = new ServiceClientMapper();
+        for (com.microsoft.typespec.http.client.generator.core.extension.model.codemodel.Client client : clients) {
+            ServiceClient serviceClient = mapper.map(client, codeModel);
+            if (serviceClient != null) {
+                serviceClientsMap.put(serviceClient, client);
+            }
+        }
+        return serviceClientsMap;
     }
 
     private void addBuilderTraits(ClientBuilder clientBuilder, ServiceClient serviceClient) {
@@ -615,9 +625,19 @@ public ObjectSchema parseHeader(Operation operation, JavaSettings settings) {
     }
 
     protected String getResponseHeaderName(Header header) {
-        // We should use header.getLanguage().getDefault().getName()
-        // kept as header.getHeader() for backward compatibility
-        return header.getHeader();
+        String clientName;
+        if (header.getLanguage() != null
+            && header.getLanguage().getJava() != null
+            && !CoreUtils.isNullOrEmpty(header.getLanguage().getJava().getName())) {
+            clientName = header.getLanguage().getJava().getName();
+        } else if (header.getLanguage() != null
+            && header.getLanguage().getDefault() != null
+            && !CoreUtils.isNullOrEmpty(header.getLanguage().getDefault().getName())) {
+            clientName = header.getLanguage().getDefault().getName();
+        } else {
+            clientName = header.getHeader();
+        }
+        return clientName;
     }
 
     private ClientResponse parseResponse(Operation method, List<ClientModel> models, JavaSettings settings) {
@@ -693,26 +713,16 @@ private static ModuleInfo getModuleInfo(List<String> modelsPackages, Collection<
      */
     protected List<String> getModelsPackages(List<ClientModel> clientModels, List<EnumType> enumTypes,
         List<ClientResponse> responseModels) {
+        Set<String> packages = new LinkedHashSet<>();
 
-        List<String> ret = List.of();
-
-        JavaSettings settings = JavaSettings.getInstance();
-        boolean hasModels = !settings.isDataPlaneClient()   // not DPG
-            // defined models package (it is defined by default)
-            && (settings.getModelsSubpackage() != null && !settings.getModelsSubpackage().isEmpty())
-            // models package is not same as implementation package
-            && !settings.getModelsSubpackage().equals(settings.getImplementationSubpackage());
-
-        if (hasModels) {
-            Set<String> packages = clientModels.stream().map(ClientModel::getPackage).collect(Collectors.toSet());
-
-            packages.addAll(enumTypes.stream().map(EnumType::getPackage).collect(Collectors.toSet()));
-            packages.addAll(responseModels.stream().map(ClientResponse::getPackage).collect(Collectors.toSet()));
-
-            ret = new ArrayList<>(packages);
-        }
+        clientModels.stream().filter(ModelUtil::isGeneratingModel).map(ClientModel::getPackage).forEach(packages::add);
+        enumTypes.stream().filter(ModelUtil::isGeneratingModel).map(EnumType::getPackage).forEach(packages::add);
+        responseModels.stream()
+            .filter(ModelUtil::isGeneratingModel)
+            .map(ClientResponse::getPackage)
+            .forEach(packages::add);
 
-        return ret;
+        return new ArrayList<>(packages);
     }
 
     public static ClassType getClientResponseClassType(Operation method, List<ClientModel> models,

packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/mapper/PrimitiveMapper.java

@@ -64,7 +64,7 @@ protected IType createPrimitiveType(PrimitiveSchema primaryType) {
                 return PrimitiveType.CHAR;
 
             case DATE:
-                return isLowLevelClient ? ClassType.STRING : ClassType.LOCAL_DATE;
+                return ClassType.LOCAL_DATE;
 
             case DATE_TIME:
                 DateTimeSchema dateTimeSchema = (DateTimeSchema) primaryType;
@@ -127,7 +127,7 @@ protected IType createPrimitiveType(PrimitiveSchema primaryType) {
                 return durationType;
 
             case UNIXTIME:
-                return isLowLevelClient ? PrimitiveType.LONG : PrimitiveType.UNIX_TIME_LONG;
+                return PrimitiveType.UNIX_TIME_LONG;
 
             case UUID:
                 return isLowLevelClient || uuidAsString ? ClassType.STRING : ClassType.UUID;

packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/mapper/ProxyParameterMapper.java

@@ -11,6 +11,7 @@
 import com.microsoft.typespec.http.client.generator.core.extension.plugin.JavaSettings;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ArrayType;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ClassType;
+import com.microsoft.typespec.http.client.generator.core.model.clientmodel.EnumType;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.IType;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.IterableType;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ListType;
@@ -185,6 +186,8 @@ public ProxyMethodParameter map(Parameter parameter) {
     }
 
     protected boolean isRemoveModelFromParameter(Parameter parameter, IType clientType) {
-        return JavaSettings.getInstance().isDataPlaneClient();
+        boolean isEnumType = clientType instanceof EnumType;
+        boolean isClientParameter = Parameter.ImplementationLocation.CLIENT.equals(parameter.getImplementation());
+        return JavaSettings.getInstance().isDataPlaneClient() && !(isEnumType && isClientParameter);
     }
 }

packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/mapper/ServiceClientMapper.java

@@ -13,12 +13,15 @@
 import com.microsoft.typespec.http.client.generator.core.extension.model.codemodel.Scheme;
 import com.microsoft.typespec.http.client.generator.core.extension.plugin.JavaSettings;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ClassType;
+import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ClientAccessorMethod;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ClientMethod;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ClientMethodParameter;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.Constructor;
+import com.microsoft.typespec.http.client.generator.core.model.clientmodel.EnumType;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.IType;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.MethodGroupClient;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ParameterSynthesizedOrigin;
+import com.microsoft.typespec.http.client.generator.core.model.clientmodel.PipelinePolicyDetails;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.Proxy;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ProxyMethod;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.SecurityInfo;
@@ -32,9 +35,12 @@
 import io.clientcore.core.utils.CoreUtils;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -45,6 +51,8 @@ public class ServiceClientMapper implements IMapper<CodeModel, ServiceClient> {
     private static final Pattern TRAILING_FORWARD_SLASH = Pattern.compile("/+$");
     private static final Pattern URL_PATH = Pattern.compile("(?<!/)[/][^/]+");
 
+    private final Map<Client, ServiceClient> parsed = new ConcurrentHashMap<>();
+
     protected ServiceClientMapper() {
     }
 
@@ -250,8 +258,108 @@ protected List<ServiceClientProperty> processClientProperties(Client client, Str
         return serviceClientProperties;
     }
 
+    /**
+     * Maps a single TypeSpec client to a service client.
+     *
+     * @param client the code model client.
+     * @param codeModel the code model.
+     * @return the service client.
+     */
+    public ServiceClient map(Client client, CodeModel codeModel) {
+        if (parsed.containsKey(client)) {
+            return parsed.get(client);
+        }
+
+        ServiceClient.Builder builder = createClientBuilder();
+
+        String baseName = SchemaUtil.getJavaName(client);
+        String className = ClientModelUtil.getClientImplementClassName(baseName);
+        String packageName = ClientModelUtil.getServiceClientPackageName(className);
+        builder.interfaceName(baseName).className(className).packageName(packageName);
+        if (client.getLanguage().getJava() != null
+            && !CoreUtils.isNullOrEmpty(client.getLanguage().getJava().getNamespace())) {
+            builder.builderPackageName(client.getLanguage().getJava().getNamespace());
+        }
+
+        builder.builderDisabled(!client.isBuildMethodPublic());
+
+        Proxy proxy = null;
+        OperationGroup clientOperationGroup = client.getOperationGroups()
+            .stream()
+            .filter(og -> CoreUtils.isNullOrEmpty(SchemaUtil.getJavaName(og)))
+            .findFirst()
+            .orElse(null);
+        if (clientOperationGroup != null) {
+            proxy = processClientOperations(builder, clientOperationGroup.getOperations(), baseName);
+        } else {
+            builder.clientMethods(Collections.emptyList());
+        }
+
+        List<ServiceClientProperty> properties = processClientProperties(client,
+            client.getServiceVersion() == null ? null : client.getServiceVersion().getLanguage().getJava().getName());
+
+        List<MethodGroupClient> methodGroupClients = new ArrayList<>();
+        client.getOperationGroups()
+            .stream()
+            .filter(og -> !CoreUtils.isNullOrEmpty(SchemaUtil.getJavaName(og)))
+            .forEach(og -> methodGroupClients.add(Mappers.getMethodGroupMapper().map(og, properties)));
+        builder.methodGroupClients(methodGroupClients);
+
+        if (proxy == null
+            && CoreUtils.isNullOrEmpty(methodGroupClients)
+            && CoreUtils.isNullOrEmpty(client.getSubClients())) {
+            // No operation in this client, no operation group, no sub client as well. Abort the processing.
+            return null;
+        }
+
+        if (proxy == null && !CoreUtils.isNullOrEmpty(methodGroupClients)) {
+            proxy = methodGroupClients.iterator().next().getProxy();
+        }
+
+        // TODO (weidxu): security definition could be different for different client
+        processParametersAndConstructors(builder, client, codeModel, properties, proxy);
+
+        processPipelinePolicyDetails(builder, client);
+
+        builder.crossLanguageDefinitionId(SchemaUtil.getCrossLanguageDefinitionId(client));
+
+        List<ClientAccessorMethod> clientAccessorMethods = new ArrayList<>();
+        for (Client subClient : client.getSubClients()) {
+            if (subClient.isParentAccessorPublic()) {
+                ServiceClient subServiceClient = this.map(subClient, codeModel);
+                clientAccessorMethods.add(new ClientAccessorMethod(subServiceClient));
+            }
+        }
+        builder.clientAccessorMethods(clientAccessorMethods);
+
+        ServiceClient serviceClient = builder.build();
+
+        clientAccessorMethods.forEach(m -> {
+            m.setServiceClient(serviceClient);
+            m.getSubClient().setParentClient(serviceClient);
+        });
+
+        parsed.put(client, serviceClient);
+        return serviceClient;
+    }
+
+    private static void processPipelinePolicyDetails(ServiceClient.Builder builder, Client client) {
+        // handle corner case of RequestIdPolicy with header name "client-request-id"
+        final String clientRequestIdHeaderName = "client-request-id";
+        final boolean clientRequestIdHeaderInClient = client.getOperationGroups()
+            .stream()
+            .flatMap(og -> og.getOperations().stream())
+            .anyMatch(o -> o.getSpecialHeaders() != null && o.getSpecialHeaders().contains(clientRequestIdHeaderName));
+        if (clientRequestIdHeaderInClient) {
+            builder
+                .pipelinePolicyDetails(new PipelinePolicyDetails().setRequestIdHeaderName(clientRequestIdHeaderName));
+        }
+    }
+
     protected boolean isRemoveModelFromParameter(Parameter parameter, IType type) {
-        return JavaSettings.getInstance().isDataPlaneClient();
+        boolean isEnumType = type instanceof EnumType;
+        boolean isClientParameter = Parameter.ImplementationLocation.CLIENT.equals(parameter.getImplementation());
+        return JavaSettings.getInstance().isDataPlaneClient() && !(isEnumType && isClientParameter);
     }
 
     protected void processParametersAndConstructors(ServiceClient.Builder builder, Client client, CodeModel codeModel,

packages/http-client-java/generator/http-client-generator/src/main/java/com/microsoft/typespec/http/client/generator/util/ModelUtil.java → packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/util/ModelUtil.java

@@ -1,7 +1,7 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-package com.microsoft.typespec.http.client.generator.util;
+package com.microsoft.typespec.http.client.generator.core.util;
 
 import com.microsoft.typespec.http.client.generator.core.extension.plugin.JavaSettings;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ClassType;
@@ -11,7 +11,6 @@
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.IType;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ImplementationDetails;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.UnionModel;
-import com.microsoft.typespec.http.client.generator.core.util.ClientModelUtil;
 
 public final class ModelUtil {
 

packages/http-client-java/generator/http-client-generator-mgmt/src/main/java/com/microsoft/typespec/http/client/generator/mgmt/mapper/FluentMapperFactory.java

@@ -3,16 +3,14 @@
 
 package com.microsoft.typespec.http.client.generator.mgmt.mapper;
 
-import com.microsoft.typespec.http.client.generator.core.mapper.ChoiceMapper;
 import com.microsoft.typespec.http.client.generator.core.mapper.ClientMethodMapper;
 import com.microsoft.typespec.http.client.generator.core.mapper.DefaultMapperFactory;
 import com.microsoft.typespec.http.client.generator.core.mapper.ExceptionMapper;
 import com.microsoft.typespec.http.client.generator.core.mapper.MethodGroupMapper;
 import com.microsoft.typespec.http.client.generator.core.mapper.ModelMapper;
+import com.microsoft.typespec.http.client.generator.core.mapper.ModelPropertyMapper;
 import com.microsoft.typespec.http.client.generator.core.mapper.ObjectMapper;
-import com.microsoft.typespec.http.client.generator.core.mapper.PrimitiveMapper;
 import com.microsoft.typespec.http.client.generator.core.mapper.ProxyMethodMapper;
-import com.microsoft.typespec.http.client.generator.core.mapper.SealedChoiceMapper;
 
 public class FluentMapperFactory extends DefaultMapperFactory {
 
@@ -41,23 +39,13 @@ public ClientMethodMapper getClientMethodMapper() {
         return FluentClientMethodMapper.getInstance();
     }
 
-    @Override
-    public PrimitiveMapper getPrimitiveMapper() {
-        return FluentPrimitiveMapper.getInstance();
-    }
-
     @Override
     public ModelMapper getModelMapper() {
         return FluentModelMapper.getInstance();
     }
 
     @Override
-    public ChoiceMapper getChoiceMapper() {
-        return FluentChoiceMapper.getInstance();
-    }
-
-    @Override
-    public SealedChoiceMapper getSealedChoiceMapper() {
-        return FluentSealedChoiceMapper.getInstance();
+    public ModelPropertyMapper getModelPropertyMapper() {
+        return FluentModelPropertyMapper.getInstance();
     }
 }

packages/http-client-java/generator/http-client-generator-mgmt/src/main/java/com/microsoft/typespec/http/client/generator/mgmt/mapper/FluentModelMapper.java

@@ -3,6 +3,7 @@
 
 package com.microsoft.typespec.http.client.generator.mgmt.mapper;
 
+import com.microsoft.typespec.http.client.generator.core.extension.model.codemodel.ObjectSchema;
 import com.microsoft.typespec.http.client.generator.core.mapper.ModelMapper;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ClassType;
 import com.microsoft.typespec.http.client.generator.mgmt.model.FluentType;
@@ -19,6 +20,11 @@ public static FluentModelMapper getInstance() {
         return INSTANCE;
     }
 
+    @Override
+    public boolean isPlainObject(ObjectSchema compositeType) {
+        return false;
+    }
+
     @Override
     protected boolean isPredefinedModel(ClassType modelType) {
         return !FluentType.nonResourceType(modelType)