stub for accessor

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

@@ -166,8 +166,13 @@ protected Proxy processClientOperations(ServiceClient.Builder builder, List<Oper
         String baseName) {
         JavaSettings settings = JavaSettings.getInstance();
 
+        if (operations.isEmpty()) {
+            builder.clientMethods(Collections.emptyList());
+            return null;
+        }
+
         // TODO: Assume all operations share the same base url
-        String baseUrl = operations.isEmpty() ? "" : getBaseUrl(operations.iterator().next());
+        String baseUrl = getBaseUrl(operations.iterator().next());
         Proxy.Builder proxyBuilder
             = getProxyBuilder().name(baseName + "Service").clientTypeName(baseName).baseURL(baseUrl);
         List<ProxyMethod> restAPIMethods = new ArrayList<>();

packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/model/clientmodel/ServiceClient.java

@@ -5,6 +5,7 @@
 
 import com.microsoft.typespec.http.client.generator.core.extension.plugin.JavaSettings;
 import com.microsoft.typespec.http.client.generator.core.util.ClientModelUtil;
+import java.util.Collections;
 import java.util.List;
 import java.util.Set;
 
@@ -80,6 +81,8 @@ public class ServiceClient {
 
     private PipelinePolicyDetails pipelinePolicyDetails;
 
+    private List<ServiceClient> subClients;
+
     /**
      * Create a new ServiceClient with the provided properties.
      * 
@@ -104,7 +107,7 @@ protected ServiceClient(String packageName, String className, String interfaceNa
         ClientMethodParameter httpPipelineParameter, ClientMethodParameter serializerAdapterParameter,
         ClientMethodParameter defaultPollIntervalParameter, String defaultCredentialScopes, boolean builderDisabled,
         String builderPackageName, SecurityInfo securityInfo, String baseUrl,
-        PipelinePolicyDetails pipelinePolicyDetails, String crossLanguageDefinitionId) {
+        PipelinePolicyDetails pipelinePolicyDetails, List<ServiceClient> subClients, String crossLanguageDefinitionId) {
         this.packageName = packageName;
         this.className = className;
         this.interfaceName = interfaceName;
@@ -125,6 +128,7 @@ protected ServiceClient(String packageName, String className, String interfaceNa
         this.securityInfo = securityInfo;
         this.baseUrl = baseUrl;
         this.pipelinePolicyDetails = pipelinePolicyDetails;
+        this.subClients = subClients;
         this.crossLanguageDefinitionId = crossLanguageDefinitionId;
     }
 
@@ -222,6 +226,10 @@ public PipelinePolicyDetails getPipelinePolicyDetails() {
         return pipelinePolicyDetails;
     }
 
+    public List<ServiceClient> getSubClients() {
+        return subClients;
+    }
+
     public String getCrossLanguageDefinitionId() {
         return crossLanguageDefinitionId;
     }
@@ -332,6 +340,7 @@ public static class Builder {
         protected SecurityInfo securityInfo;
         protected String baseUrl;
         protected PipelinePolicyDetails pipelinePolicyDetails;
+        protected List<ServiceClient> subClients = Collections.emptyList();
         private String crossLanguageDefinitionId;
 
         /**
@@ -543,16 +552,22 @@ public Builder pipelinePolicyDetails(PipelinePolicyDetails pipelinePolicyDetails
             return this;
         }
 
-        public ServiceClient build() {
-            return new ServiceClient(packageName, className, interfaceName, proxy, methodGroupClients, properties,
-                constructors, clientMethods, azureEnvironmentParameter, tokenCredentialParameter, httpPipelineParameter,
-                serializerAdapterParameter, defaultPollIntervalParameter, defaultCredentialScopes, builderDisabled,
-                builderPackageName, securityInfo, baseUrl, pipelinePolicyDetails, crossLanguageDefinitionId);
+        public Builder subClients(List<ServiceClient> subClients) {
+            this.subClients = subClients;
+            return this;
         }
 
         public Builder crossLanguageDefinitionId(String crossLanguageDefinitionId) {
             this.crossLanguageDefinitionId = crossLanguageDefinitionId;
             return this;
         }
+
+        public ServiceClient build() {
+            return new ServiceClient(packageName, className, interfaceName, proxy, methodGroupClients, properties,
+                constructors, clientMethods, azureEnvironmentParameter, tokenCredentialParameter, httpPipelineParameter,
+                serializerAdapterParameter, defaultPollIntervalParameter, defaultCredentialScopes, builderDisabled,
+                builderPackageName, securityInfo, baseUrl, pipelinePolicyDetails, subClients,
+                crossLanguageDefinitionId);
+        }
     }
 }

packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/model/clientmodel/android/AndroidServiceClient.java

@@ -11,6 +11,7 @@
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.SecurityInfo;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ServiceClient;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ServiceClientProperty;
+import java.util.Collections;
 import java.util.List;
 import java.util.Set;
 
@@ -26,7 +27,7 @@ protected AndroidServiceClient(String packageName, String className, String inte
         super(packageName, className, interfaceName, proxy, methodGroupClients, properties, constructors, clientMethods,
             azureEnvironmentParameter, tokenCredentialParameter, httpPipelineParameter, serializerAdapterParameter,
             defaultPollIntervalParameter, defaultCredentialScopes, builderDisabled, null, securityInfo, baseUrl, null,
-            null);
+            Collections.emptyList(), null);
     }
 
     @Override

packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/template/ServiceAsyncClientTemplate.java

@@ -16,6 +16,7 @@
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.GenericType;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.MethodGroupClient;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ServiceClient;
+import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ServiceClientProperty;
 import com.microsoft.typespec.http.client.generator.core.model.javamodel.JavaClass;
 import com.microsoft.typespec.http.client.generator.core.model.javamodel.JavaContext;
 import com.microsoft.typespec.http.client.generator.core.model.javamodel.JavaFile;
@@ -67,6 +68,8 @@ public final void write(AsyncSyncClient asyncClient, JavaFile javaFile) {
         imports.add(builderPackageName + "." + builderClassName);
         addServiceClientAnnotationImports(imports);
 
+        imports.addAll(getSubClientImports(serviceClient, true));
+
         Templates.getConvenienceAsyncMethodTemplate().addImports(imports, asyncClient.getConvenienceMethods());
 
         javaFile.declareImport(imports);
@@ -133,6 +136,8 @@ public final void write(AsyncSyncClient asyncClient, JavaFile javaFile) {
                     });
             }
 
+            writeSubClientAccessors(serviceClient, classBlock, true);
+
             writeConvenienceMethods(asyncClient.getConvenienceMethods(), classBlock);
 
             ServiceAsyncClientTemplate.addEndpointMethod(classBlock, asyncClient.getClientBuilder(), serviceClient,
@@ -207,6 +212,48 @@ static void addEndpointMethod(JavaClass classBlock, ClientBuilder clientBuilder,
         }
     }
 
+    static Set<String> getSubClientImports(ServiceClient serviceClient, boolean isAsync) {
+        Set<String> imports = new HashSet<>();
+        for (ServiceClient subClient : serviceClient.getSubClients()) {
+            final String subClientClassName = isAsync
+                    ? ClientModelUtil.clientNameToAsyncClientName(subClient.getClientBaseName())
+                    : subClient.getClientBaseName();
+
+            final String packageName = ClientModelUtil.getAsyncSyncClientPackageName(serviceClient);
+            imports.add(packageName + "." + subClientClassName);
+        }
+        return imports;
+    }
+
+    static void writeSubClientAccessors(ServiceClient serviceClient, JavaClass classBlock, boolean isAsync) {
+        // Add accessors to sub clients
+        for (ServiceClient subClient : serviceClient.getSubClients()) {
+            final String subClientClassName = isAsync
+                    ? ClientModelUtil.clientNameToAsyncClientName(subClient.getClientBaseName())
+                    : subClient.getClientBaseName();
+
+            List<ServiceClientProperty> additionalProperties
+                    = ClientModelUtil.getAdditionalPropertiesInSubClient(serviceClient, subClient);
+
+            // TODO: do we overload the getter, if there is optional property?
+            classBlock.javadocComment(comment -> {
+                comment.description("Gets the " + subClientClassName + ".");
+                for (ServiceClientProperty property : additionalProperties) {
+                    comment.param(property.getName(), property.getDescription());
+                }
+                comment.methodReturns("the " + subClientClassName);
+            });
+            String methodSignature = subClientClassName + " get" + subClientClassName + "( "
+                    + additionalProperties.stream()
+                    .map(p -> p.getType() + " " + p.getName())
+                    .collect(Collectors.joining(", "))
+                    + ")";
+            classBlock.publicMethod(methodSignature, method -> {
+                method.methodReturn("null");
+            });
+        }
+    }
+
     private void writeConvenienceMethods(List<ConvenienceMethod> convenienceMethods, JavaClass classBlock) {
         Set<GenericType> typeReferenceStaticClasses = new HashSet<>();
 

packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/template/ServiceSyncClientTemplate.java

@@ -60,6 +60,8 @@ public final void write(AsyncSyncClient syncClient, JavaFile javaFile) {
         imports.add(builderPackageName + "." + builderClassName);
         addServiceClientAnnotationImport(imports);
 
+        imports.addAll(ServiceAsyncClientTemplate.getSubClientImports(serviceClient, false));
+
         Templates.getConvenienceSyncMethodTemplate().addImports(imports, syncClient.getConvenienceMethods());
 
         javaFile.declareImport(imports);
@@ -117,6 +119,8 @@ protected void writeClass(AsyncSyncClient syncClient, JavaClass classBlock, Java
                 });
         }
 
+        ServiceAsyncClientTemplate.writeSubClientAccessors(serviceClient, classBlock, false);
+
         writeMethods(syncClient, classBlock);
     }
 

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

@@ -27,6 +27,7 @@
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ImplementationDetails;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.MethodGroupClient;
 import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ServiceClient;
+import com.microsoft.typespec.http.client.generator.core.model.clientmodel.ServiceClientProperty;
 import com.microsoft.typespec.http.client.generator.core.model.javamodel.JavaVisibility;
 import java.net.URI;
 import java.util.ArrayList;
@@ -79,7 +80,7 @@ public static void getAsyncSyncClients(Client client, ServiceClient serviceClien
         boolean generateAsyncMethods = JavaSettings.getInstance().isGenerateAsyncMethods();
         boolean generateSyncMethods = JavaSettings.getInstance().isGenerateSyncMethods();
 
-        if (serviceClient.getProxy() != null) {
+        if (serviceClient.getProxy() != null || CoreUtils.isNullOrEmpty(serviceClient.getMethodGroupClients())) {
             AsyncSyncClient.Builder builder = new AsyncSyncClient.Builder().packageName(packageName)
                 .serviceClient(serviceClient)
                 .crossLanguageDefinitionId(client.getCrossLanguageDefinitionId());
@@ -308,6 +309,18 @@ public static String getServiceClientInterfacePackageName() {
         }
     }
 
+    public static List<ServiceClientProperty> getAdditionalPropertiesInSubClient(ServiceClient client,
+        ServiceClient subClient) {
+        List<ServiceClientProperty> additionalProperties = new ArrayList<>();
+        for (ServiceClientProperty property : subClient.getProperties()) {
+            String name = property.getName();
+            if (client.getProperties().stream().noneMatch(p -> name.equals(p.getName()))) {
+                additionalProperties.add(property);
+            }
+        }
+        return additionalProperties;
+    }
+
     public static String getClientDefaultValueOrConstantValue(Parameter parameter) {
         String clientDefaultValueOrConstantValue = parameter.getClientDefaultValue();
         if (clientDefaultValueOrConstantValue == null) {

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

@@ -66,12 +66,14 @@ public ServiceClient map(Client client, CodeModel codeModel) {
             .forEach(og -> methodGroupClients.add(Mappers.getMethodGroupMapper().map(og, properties)));
         builder.methodGroupClients(methodGroupClients);
 
-        if (proxy == null && CoreUtils.isNullOrEmpty(methodGroupClients)) {
-            // No operation in this client, and no operation group as well. Abort the processing.
+        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) {
+        if (proxy == null && !CoreUtils.isNullOrEmpty(methodGroupClients)) {
             proxy = methodGroupClients.iterator().next().getProxy();
         }