[OLINGO-832] Added new SerializerStreamResult

lib/server-api/src/main/java/org/apache/olingo/server/api/serializer/ODataSerializer.java

@@ -20,6 +20,7 @@ package org.apache.olingo.server.api.serializer;
 
 import org.apache.olingo.commons.api.data.Entity;
 import org.apache.olingo.commons.api.data.AbstractEntityCollection;
+import org.apache.olingo.commons.api.data.EntityIterator;
 import org.apache.olingo.commons.api.data.Property;
 import org.apache.olingo.commons.api.edm.EdmComplexType;
 import org.apache.olingo.commons.api.edm.EdmEntitySet;
@@ -63,6 +64,16 @@ public interface ODataSerializer {
   SerializerResult entityCollection(ServiceMetadata metadata, EdmEntityType entityType,
       AbstractEntityCollection entitySet, EntityCollectionSerializerOptions options) throws SerializerException;
 
+  /**
+   * Writes entity-collection data into an InputStream.
+   * @param metadata metadata for the service
+   * @param entityType the {@link EdmEntityType}
+   * @param entities the data of the entity set
+   * @param options options for the serializer
+   */
+  SerializerStreamResult entityCollectionStreamed(ServiceMetadata metadata, EdmEntityType entityType,
+      EntityIterator entities, EntityCollectionSerializerOptions options) throws SerializerException;
+
   /**
    * Writes entity data into an InputStream.
    * @param metadata metadata for the service

lib/server-api/src/main/java/org/apache/olingo/server/api/serializer/SerializerStreamResult.java

@@ -0,0 +1,32 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.olingo.server.api.serializer;
+
+import org.apache.olingo.server.api.ODataContent;
+
+/**
+ * Result type for {@link ODataSerializer} methods
+ */
+public interface SerializerStreamResult {
+  /**
+   * Returns the content as ODataContent
+   * @return content
+   */
+  ODataContent getODataContent();
+}

lib/server-core/src/main/java/org/apache/olingo/server/core/ODataBasicContent.java

@@ -0,0 +1,59 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.olingo.server.core;
+
+import org.apache.olingo.server.api.ODataContent;
+import org.apache.olingo.server.api.WriteContentErrorCallback;
+
+import java.io.InputStream;
+import java.nio.channels.Channels;
+import java.nio.channels.ReadableByteChannel;
+import java.nio.channels.WritableByteChannel;
+
+public class ODataBasicContent implements ODataContent {
+  private final ReadableByteChannel channel;
+
+  public ODataBasicContent(ReadableByteChannel channel) {
+    this.channel = channel;
+  }
+
+  public ODataBasicContent(InputStream stream) {
+    this(Channels.newChannel(stream));
+  }
+
+  @Override
+  public ReadableByteChannel getChannel() {
+    return channel;
+  }
+
+  @Override
+  public void write(WritableByteChannel channel) {
+
+  }
+
+  @Override
+  public void write(WritableByteChannel channel, WriteContentErrorCallback callback) {
+
+  }
+
+  @Override
+  public boolean isWriteSupported() {
+    return false;
+  }
+}

lib/server-core/src/main/java/org/apache/olingo/server/core/ODataImpl.java

@@ -18,6 +18,9 @@
  */
 package org.apache.olingo.server.core;
 
+import java.util.Collection;
+import java.util.List;
+
 import org.apache.olingo.commons.api.edm.EdmPrimitiveType;
 import org.apache.olingo.commons.api.edm.EdmPrimitiveTypeKind;
 import org.apache.olingo.commons.api.edm.provider.CsdlEdmProvider;
@@ -45,13 +48,10 @@ import org.apache.olingo.server.core.deserializer.xml.ODataXmlDeserializer;
 import org.apache.olingo.server.core.etag.ETagHelperImpl;
 import org.apache.olingo.server.core.prefer.PreferencesImpl;
 import org.apache.olingo.server.core.serializer.FixedFormatSerializerImpl;
-import org.apache.olingo.server.core.serializer.json.ODataJsonStreamSerializer;
+import org.apache.olingo.server.core.serializer.json.ODataJsonSerializer;
 import org.apache.olingo.server.core.serializer.xml.ODataXmlSerializer;
 import org.apache.olingo.server.core.uri.UriHelperImpl;
 
-import java.util.Collection;
-import java.util.List;
-
 public class ODataImpl extends OData {
 
   @Override
@@ -63,8 +63,7 @@ public class ODataImpl extends OData {
       if (metadata == null
           || ContentType.VALUE_ODATA_METADATA_MINIMAL.equals(metadata)
           || ContentType.VALUE_ODATA_METADATA_NONE.equals(metadata)) {
-//        serializer = new ODataJsonSerializer(contentType);
-        serializer = new ODataJsonStreamSerializer(contentType);
+        serializer = new ODataJsonSerializer(contentType);
       }
     } else if (contentType.isCompatible(ContentType.APPLICATION_XML)
         || contentType.isCompatible(ContentType.APPLICATION_ATOM_XML)) {

lib/server-core/src/main/java/org/apache/olingo/server/core/ODataWritableContent.java

@@ -16,7 +16,7 @@
  * specific language governing permissions and limitations
  * under the License.
  */
-package org.apache.olingo.server.core.serializer;
+package org.apache.olingo.server.core;
 
 import com.fasterxml.jackson.core.JsonFactory;
 import com.fasterxml.jackson.core.JsonGenerator;
@@ -29,12 +29,12 @@ import org.apache.olingo.server.api.ServiceMetadata;
 import org.apache.olingo.server.api.WriteContentErrorCallback;
 import org.apache.olingo.server.api.serializer.EntitySerializerOptions;
 import org.apache.olingo.server.api.serializer.SerializerException;
-import org.apache.olingo.server.api.serializer.SerializerResult;
-import org.apache.olingo.server.core.serializer.json.ODataJsonStreamSerializer;
+import org.apache.olingo.server.api.serializer.SerializerStreamResult;
+import org.apache.olingo.server.core.serializer.SerializerStreamResultImpl;
+import org.apache.olingo.server.core.serializer.json.ODataJsonSerializer;
 import org.apache.olingo.server.core.serializer.utils.CircleStreamBuffer;
 
 import java.io.IOException;
-import java.io.InputStream;
 import java.io.OutputStream;
 import java.nio.ByteBuffer;
 import java.nio.channels.Channels;
@@ -42,21 +42,21 @@ import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.WritableByteChannel;
 import java.nio.charset.Charset;
 
-public class ChannelSerializerResult implements ODataContent {
+public class ODataWritableContent implements ODataContent {
   private StreamChannel channel;
 
   private static class StreamChannel implements ReadableByteChannel {
     private static final Charset DEFAULT = Charset.forName("UTF-8");
     private ByteBuffer head;
     private ByteBuffer tail;
-    private ODataJsonStreamSerializer jsonSerializer;
+    private ODataJsonSerializer jsonSerializer;
     private EntityIterator coll;
     private ServiceMetadata metadata;
     private EdmEntityType entityType;
     private EntitySerializerOptions options;
 
     public StreamChannel(EntityIterator coll, EdmEntityType entityType, String head,
-                         ODataJsonStreamSerializer jsonSerializer, ServiceMetadata metadata,
+                         ODataJsonSerializer jsonSerializer, ServiceMetadata metadata,
                          EntitySerializerOptions options, String tail) {
       this.coll = coll;
       this.entityType = entityType;
@@ -217,52 +217,51 @@ public class ChannelSerializerResult implements ODataContent {
     throw new ODataRuntimeException("error handling not yet supported");
   }
 
-  private ChannelSerializerResult(StreamChannel channel) {
+  private ODataWritableContent(StreamChannel channel) {
     this.channel = channel;
   }
 
-  public static SerializerResultBuilder with(EntityIterator coll, EdmEntityType entityType,
-                                             ODataJsonStreamSerializer jsonSerializer,
+  public static ODataWritableContentBuilder with(EntityIterator coll, EdmEntityType entityType,
+                                             ODataJsonSerializer jsonSerializer,
                                              ServiceMetadata metadata, EntitySerializerOptions options) {
-    return new SerializerResultBuilder(coll, entityType, jsonSerializer, metadata, options);
+    return new ODataWritableContentBuilder(coll, entityType, jsonSerializer, metadata, options);
   }
 
-  public static class SerializerResultBuilder {
-    private ODataJsonStreamSerializer jsonSerializer;
-    private EntityIterator coll;
+  public static class ODataWritableContentBuilder {
+    private ODataJsonSerializer jsonSerializer;
+    private EntityIterator entities;
     private ServiceMetadata metadata;
     private EdmEntityType entityType;
     private EntitySerializerOptions options;
     private String head;
     private String tail;
 
-    public SerializerResultBuilder(EntityIterator coll, EdmEntityType entityType,
-                                   ODataJsonStreamSerializer jsonSerializer,
+    public ODataWritableContentBuilder(EntityIterator entities, EdmEntityType entityType,
+                                   ODataJsonSerializer jsonSerializer,
                                    ServiceMetadata metadata, EntitySerializerOptions options) {
-      this.coll = coll;
+      this.entities = entities;
       this.entityType = entityType;
       this.jsonSerializer = jsonSerializer;
       this.metadata = metadata;
       this.options = options;
     }
 
-    public SerializerResultBuilder addHead(String head) {
+    public ODataWritableContentBuilder addHead(String head) {
       this.head = head;
       return this;
     }
 
-    public SerializerResultBuilder addTail(String tail) {
+    public ODataWritableContentBuilder addTail(String tail) {
       this.tail = tail;
       return this;
     }
 
     public ODataContent buildContent() {
-      StreamChannel input = new StreamChannel(coll, entityType, head, jsonSerializer, metadata, options, tail);
-      return new ChannelSerializerResult(input);
+      StreamChannel input = new StreamChannel(entities, entityType, head, jsonSerializer, metadata, options, tail);
+      return new ODataWritableContent(input);
     }
-    public SerializerResult build() {
-      StreamChannel input = new StreamChannel(coll, entityType, head, jsonSerializer, metadata, options, tail);
-      return SerializerResultImpl.with().content(new ChannelSerializerResult(input)).build();
+    public SerializerStreamResult build() {
+      return SerializerStreamResultImpl.with().content(buildContent()).build();
     }
   }
 }

lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/SerializerResultImpl.java

@@ -20,6 +20,8 @@ package org.apache.olingo.server.core.serializer;
 
 import org.apache.olingo.server.api.ODataContent;
 import org.apache.olingo.server.api.serializer.SerializerResult;
+import org.apache.olingo.server.api.serializer.SerializerStreamResult;
+import org.apache.olingo.server.core.ODataBasicContent;
 import org.apache.olingo.server.core.serializer.utils.ResultHelper;
 
 import java.io.InputStream;
@@ -38,6 +40,9 @@ public class SerializerResultImpl implements SerializerResult {
 
   @Override
   public ODataContent getODataContent() {
+    if(oDataContent == null && content != null) {
+      return new ODataBasicContent(content);
+    }
     return oDataContent;
   }
 

lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/SerializerStreamResultImpl.java

@@ -0,0 +1,67 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.olingo.server.core.serializer;
+
+import java.io.InputStream;
+
+import org.apache.olingo.server.api.ODataContent;
+import org.apache.olingo.server.api.serializer.SerializerResult;
+import org.apache.olingo.server.api.serializer.SerializerStreamResult;
+
+public class SerializerStreamResultImpl implements SerializerStreamResult {
+  private InputStream content;
+  private ODataContent oDataContent;
+
+  @Override
+  public ODataContent getODataContent() {
+    return oDataContent;
+  }
+
+  //  @Override
+//  public ReadableByteChannel getChannel() {
+//    return Channels.newChannel(getContent());
+//  }
+//
+//  @Override
+//  public void write(WritableByteChannel channel) {
+//    ResultHelper.copy(Channels.newChannel(content), channel);
+//  }
+//
+//  @Override
+//  public boolean isWriteSupported() {
+//    return false;
+//  }
+
+  public static SerializerResultBuilder with() {
+    return new SerializerResultBuilder();
+  }
+
+  public static class SerializerResultBuilder {
+    private SerializerStreamResultImpl result = new SerializerStreamResultImpl();
+
+    public SerializerResultBuilder content(final ODataContent content) {
+      result.oDataContent = content;
+      return this;
+    }
+
+    public SerializerStreamResult build() {
+      return result;
+    }
+  }
+}

lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/ODataJsonSerializer.java

@@ -18,8 +18,10 @@
  */
 package org.apache.olingo.server.core.serializer.json;
 
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.nio.charset.Charset;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
@@ -30,6 +32,7 @@ import org.apache.olingo.commons.api.data.ComplexValue;
 import org.apache.olingo.commons.api.data.ContextURL;
 import org.apache.olingo.commons.api.data.Entity;
 import org.apache.olingo.commons.api.data.AbstractEntityCollection;
+import org.apache.olingo.commons.api.data.EntityIterator;
 import org.apache.olingo.commons.api.data.Link;
 import org.apache.olingo.commons.api.data.Linked;
 import org.apache.olingo.commons.api.data.Property;
@@ -57,11 +60,13 @@ import org.apache.olingo.server.api.serializer.ReferenceCollectionSerializerOpti
 import org.apache.olingo.server.api.serializer.ReferenceSerializerOptions;
 import org.apache.olingo.server.api.serializer.SerializerException;
 import org.apache.olingo.server.api.serializer.SerializerResult;
+import org.apache.olingo.server.api.serializer.SerializerStreamResult;
 import org.apache.olingo.server.api.uri.UriHelper;
 import org.apache.olingo.server.api.uri.queryoption.ExpandItem;
 import org.apache.olingo.server.api.uri.queryoption.ExpandOption;
 import org.apache.olingo.server.api.uri.queryoption.SelectOption;
 import org.apache.olingo.server.core.serializer.AbstractODataSerializer;
+import org.apache.olingo.server.core.ODataWritableContent;
 import org.apache.olingo.server.core.serializer.SerializerResultImpl;
 import org.apache.olingo.server.core.serializer.utils.CircleStreamBuffer;
 import org.apache.olingo.server.core.serializer.utils.ContentTypeHelper;
@@ -175,6 +180,53 @@ public class ODataJsonSerializer extends AbstractODataSerializer {
     }
   }
 
+  @Override
+  public SerializerStreamResult entityCollectionStreamed(ServiceMetadata metadata, EdmEntityType entityType,
+      EntityIterator entities, EntityCollectionSerializerOptions options) throws SerializerException {
+
+    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
+    SerializerException cachedException = null;
+    try {
+      JsonGenerator json = new JsonFactory().createGenerator(outputStream);
+      json.writeStartObject();
+
+      final ContextURL contextURL = checkContextURL(options == null ? null : options.getContextURL());
+      writeContextURL(contextURL, json);
+
+      writeMetadataETag(metadata, json);
+
+      if (options != null && options.getCount() != null && options.getCount().getValue()) {
+        writeCount(entities, json);
+      }
+      json.writeFieldName(Constants.VALUE);
+      json.writeStartArray();
+      json.close();
+      outputStream.close();
+      String temp = new String(outputStream.toByteArray(), Charset.forName("UTF-8"));
+      String head = temp.substring(0, temp.length()-2);
+
+      outputStream = new ByteArrayOutputStream();
+      outputStream.write(']');
+      outputStream.write('}');
+      outputStream.close();
+      String tail = new String(outputStream.toByteArray(), Charset.forName("UTF-8"));
+
+      EntitySerializerOptions.Builder opt = EntitySerializerOptions.with();
+      if(options != null) {
+        opt.expand(options.getExpand()).select(options
+            .getSelect()).writeOnlyReferences(options.getWriteOnlyReferences());
+      }
+      return ODataWritableContent.with(entities, entityType, this, metadata, opt.build())
+          .addHead(head).addTail(tail).build();
+    } catch (final IOException e) {
+      cachedException =
+          new SerializerException(IO_EXCEPTION_TEXT, e, SerializerException.MessageKeys.IO_EXCEPTION);
+      throw cachedException;
+    } finally {
+      closeCircleStreamBufferOutput(outputStream, cachedException);
+    }
+  }
+
   @Override
   public SerializerResult entity(final ServiceMetadata metadata, final EdmEntityType entityType,
       final Entity entity, final EntitySerializerOptions options) throws SerializerException {
@@ -229,9 +281,9 @@ public class ODataJsonSerializer extends AbstractODataSerializer {
     json.writeEndArray();
   }
 
-  protected void writeEntity(final ServiceMetadata metadata, final EdmEntityType entityType,
-      final Entity entity, final ContextURL contextURL, final ExpandOption expand,
-      final SelectOption select, final boolean onlyReference, final JsonGenerator json)
+  public void writeEntity(final ServiceMetadata metadata, final EdmEntityType entityType, final Entity entity,
+      final ContextURL contextURL, final ExpandOption expand, final SelectOption select, final boolean onlyReference,
+      final JsonGenerator json)
           throws IOException, SerializerException {
     json.writeStartObject();
     if (!isODataMetadataNone) {

lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/json/ODataJsonStreamSerializer.java

@@ -1,150 +0,0 @@
-/*
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements. See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership. The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License. You may obtain a copy of the License at
- * 
- * http://www.apache.org/licenses/LICENSE-2.0
- * 
- * Unless required by applicable law or agreed to in writing,
- * software distributed under the License is distributed on an
- * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
- * KIND, either express or implied. See the License for the
- * specific language governing permissions and limitations
- * under the License.
- */
-package org.apache.olingo.server.core.serializer.json;
-
-import com.fasterxml.jackson.core.JsonFactory;
-import com.fasterxml.jackson.core.JsonGenerator;
-import org.apache.olingo.commons.api.Constants;
-import org.apache.olingo.commons.api.data.AbstractEntityCollection;
-import org.apache.olingo.commons.api.data.ContextURL;
-import org.apache.olingo.commons.api.data.Entity;
-import org.apache.olingo.commons.api.data.EntityIterator;
-import org.apache.olingo.commons.api.edm.EdmEntityType;
-import org.apache.olingo.commons.api.format.ContentType;
-import org.apache.olingo.server.api.ServiceMetadata;
-import org.apache.olingo.server.api.serializer.EntityCollectionSerializerOptions;
-import org.apache.olingo.server.api.serializer.EntitySerializerOptions;
-import org.apache.olingo.server.api.serializer.SerializerException;
-import org.apache.olingo.server.api.serializer.SerializerResult;
-import org.apache.olingo.server.api.uri.queryoption.ExpandOption;
-import org.apache.olingo.server.api.uri.queryoption.SelectOption;
-import org.apache.olingo.server.core.serializer.ChannelSerializerResult;
-
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.nio.charset.Charset;
-
-public class ODataJsonStreamSerializer extends ODataJsonSerializer {
-
-  private final ODataJsonSerializer serializer;
-
-  public ODataJsonStreamSerializer(final ContentType contentType) {
-    super(contentType);
-    this.serializer = new ODataJsonSerializer(contentType);
-  }
-
-  @Override
-  public SerializerResult entityCollection(final ServiceMetadata metadata,
-      final EdmEntityType entityType, final AbstractEntityCollection entitySet,
-      final EntityCollectionSerializerOptions options) throws SerializerException {
-
-    EntityIterator coll;
-    if(entitySet instanceof EntityIterator) {
-      coll = (EntityIterator) entitySet;
-    } else {
-      return serializer.entityCollection(metadata, entityType, entitySet, options);
-    }
-
-    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
-    SerializerException cachedException = null;
-    try {
-      JsonGenerator json = new JsonFactory().createGenerator(outputStream);
-      json.writeStartObject();
-
-      final ContextURL contextURL = serializer.checkContextURL(options == null ? null : options.getContextURL());
-      serializer.writeContextURL(contextURL, json);
-
-      serializer.writeMetadataETag(metadata, json);
-
-      if (options != null && options.getCount() != null && options.getCount().getValue()) {
-        serializer.writeCount(entitySet, json);
-      }
-      json.writeFieldName(Constants.VALUE);
-      json.writeStartArray();
-      json.close();
-      outputStream.close();
-      String temp = new String(outputStream.toByteArray(), Charset.forName("UTF-8"));
-      String head = temp.substring(0, temp.length()-2);
-      //      if (options == null) {
-//        writeEntitySet(metadata, entityType, entitySet, null, null, false, json);
-//      } else {
-//        writeEntitySet(metadata, entityType, entitySet,
-//            options.getExpand(), options.getSelect(), options.getWriteOnlyReferences(), json);
-//      }
-
-      outputStream = new ByteArrayOutputStream();
-      outputStream.write(']');
-      outputStream.write('}');
-      outputStream.close();
-      String tail = new String(outputStream.toByteArray(), Charset.forName("UTF-8"));
-
-      EntitySerializerOptions.Builder opt = EntitySerializerOptions.with();
-      if(options != null) {
-        opt.expand(options.getExpand()).select(options
-            .getSelect()).writeOnlyReferences(options.getWriteOnlyReferences());
-      }
-//      return StreamSerializerResult.with(coll, entityType, this, metadata, opt.build())
-//          .addHead(head).addTail(tail).build();
-      return ChannelSerializerResult.with(coll, entityType, this, metadata, opt.build())
-          .addHead(head).addTail(tail).build();
-    } catch (final IOException e) {
-      cachedException =
-          new SerializerException(IO_EXCEPTION_TEXT, e, SerializerException.MessageKeys.IO_EXCEPTION);
-      throw cachedException;
-    } finally {
-      closeCircleStreamBufferOutput(outputStream, cachedException);
-    }
-  }
-
-  @Override
-  public void writeEntity(final ServiceMetadata metadata, final EdmEntityType entityType,
-      final Entity entity, final ContextURL contextURL, final ExpandOption expand,
-      final SelectOption select, final boolean onlyReference, final JsonGenerator json)
-      throws IOException, SerializerException {
-    serializer.writeEntity(metadata, entityType, entity, contextURL, expand, select, onlyReference, json);
-  }
-
-//  @Override
-//  public SerializerResult entity(final ServiceMetadata metadata, final EdmEntityType entityType,
-//      final Entity entity, final EntitySerializerOptions options) throws SerializerException {
-//    return serializer.entity(metadata, entityType, entity, options);
-//  }
-
-//  protected void writeEntitySet(final ServiceMetadata metadata, final EdmEntityType entityType,
-//      final EntityCollection entitySet, final ExpandOption expand, final SelectOption select,
-//      final boolean onlyReference, final JsonGenerator json) throws IOException,
-//      SerializerException {
-//
-//        json.writeStartArray();
-//        json.writeEndArray();
-//
-    //    json.writeStartArray();
-//    for (final Entity entity : entitySet.getEntities()) {
-//      if (onlyReference) {
-//        json.writeStartObject();
-//        json.writeStringField(Constants.JSON_ID, entity.getId().toASCIIString());
-//        json.writeEndObject();
-//      } else {
-//        serializer.writeEntity(metadata, entityType, entity, null, expand, select, false, json);
-//      }
-//    }
-//    json.writeEndArray();
-//  }
-
-}

lib/server-core/src/main/java/org/apache/olingo/server/core/serializer/xml/ODataXmlSerializer.java

@@ -36,6 +36,7 @@ import org.apache.olingo.commons.api.data.ContextURL;
 import org.apache.olingo.commons.api.data.Entity;
 import org.apache.olingo.commons.api.data.EntityCollection;
 import org.apache.olingo.commons.api.data.AbstractEntityCollection;
+import org.apache.olingo.commons.api.data.EntityIterator;
 import org.apache.olingo.commons.api.data.Link;
 import org.apache.olingo.commons.api.data.Linked;
 import org.apache.olingo.commons.api.data.Property;
@@ -52,6 +53,7 @@ import org.apache.olingo.commons.api.edm.EdmType;
 import org.apache.olingo.commons.api.edm.FullQualifiedName;
 import org.apache.olingo.commons.api.edm.constants.EdmTypeKind;
 import org.apache.olingo.commons.api.ex.ODataErrorDetail;
+import org.apache.olingo.commons.api.ex.ODataRuntimeException;
 import org.apache.olingo.commons.core.edm.primitivetype.EdmPrimitiveTypeFactory;
 import org.apache.olingo.server.api.ODataServerError;
 import org.apache.olingo.server.api.ServiceMetadata;
@@ -63,6 +65,7 @@ import org.apache.olingo.server.api.serializer.ReferenceCollectionSerializerOpti
 import org.apache.olingo.server.api.serializer.ReferenceSerializerOptions;
 import org.apache.olingo.server.api.serializer.SerializerException;
 import org.apache.olingo.server.api.serializer.SerializerResult;
+import org.apache.olingo.server.api.serializer.SerializerStreamResult;
 import org.apache.olingo.server.api.uri.queryoption.ExpandItem;
 import org.apache.olingo.server.api.uri.queryoption.ExpandOption;
 import org.apache.olingo.server.api.uri.queryoption.SelectOption;
@@ -278,6 +281,12 @@ public class ODataXmlSerializer extends AbstractODataSerializer {
     }
   }
 
+  @Override
+  public SerializerStreamResult entityCollectionStreamed(ServiceMetadata metadata, EdmEntityType entityType,
+      EntityIterator entities, EntityCollectionSerializerOptions options) throws SerializerException {
+    throw new ODataRuntimeException("entityCollectionStreamed for XML not supported (yet)");
+  }
+
   @Override
   public SerializerResult entity(final ServiceMetadata metadata, final EdmEntityType entityType,
       final Entity entity, final EntitySerializerOptions options) throws SerializerException {

lib/server-tecsvc/src/main/java/org/apache/olingo/server/tecsvc/processor/TechnicalEntityProcessor.java

@@ -39,6 +39,7 @@ import org.apache.olingo.commons.api.http.HttpHeader;
 import org.apache.olingo.commons.api.http.HttpMethod;
 import org.apache.olingo.commons.api.http.HttpStatusCode;
 import org.apache.olingo.server.api.ODataApplicationException;
+import org.apache.olingo.server.api.ODataContent;
 import org.apache.olingo.server.api.ODataLibraryException;
 import org.apache.olingo.server.api.ODataRequest;
 import org.apache.olingo.server.api.ODataResponse;
@@ -58,6 +59,7 @@ import org.apache.olingo.server.api.serializer.EntitySerializerOptions;
 import org.apache.olingo.server.api.serializer.ReferenceCollectionSerializerOptions;
 import org.apache.olingo.server.api.serializer.ReferenceSerializerOptions;
 import org.apache.olingo.server.api.serializer.SerializerResult;
+import org.apache.olingo.server.api.serializer.SerializerStreamResult;
 import org.apache.olingo.server.api.uri.UriInfo;
 import org.apache.olingo.server.api.uri.UriResourceEntitySet;
 import org.apache.olingo.server.api.uri.UriResourceNavigation;
@@ -526,22 +528,18 @@ public class TechnicalEntityProcessor extends TechnicalProcessor
       id = request.getRawBaseUri() + edmEntitySet.getName();
     }
 
-    // Serialize
-//    final SerializerResult serializerResult = (isReference) ?
-//        serializeReferenceCollection(entitySetSerialization, edmEntitySet, requestedContentType, countOption) :
-//        serializeEntityCollection(request, entitySetSerialization, edmEntitySet, edmEntityType, requestedContentType,
-//            expand, select, countOption, id);
-    final SerializerResult serializerResult = (isReference) ?
-        serializeReferenceCollection(entitySetSerialization, edmEntitySet, requestedContentType, countOption) :
-        serializeEntityStreamCollectionFixed(request,
-            entitySetSerialization, edmEntitySet, edmEntityType, requestedContentType,
-            expand, select, countOption, id);
-//    if(serializerResult.isWriteSupported()) {
-//      response.setChannel(serializerResult.getChannel());
-//    } else {
-//      response.setContent(serializerResult.getContent());
-//    }
-    response.setODataContent(serializerResult.getODataContent());
+    if(isReference) {
+      final SerializerResult serializerResult =
+          serializeReferenceCollection(entitySetSerialization, edmEntitySet, requestedContentType, countOption);
+      response.setODataContent(serializerResult.getODataContent());
+    } else {
+      final SerializerStreamResult serializerResult =
+          serializeEntityStreamCollectionFixed(request,
+              entitySetSerialization, edmEntitySet, edmEntityType, requestedContentType,
+              expand, select, countOption, id);
+
+      response.setODataContent(serializerResult.getODataContent());
+    }
     //
     response.setStatusCode(HttpStatusCode.OK.getStatusCode());
     response.setHeader(HttpHeader.CONTENT_TYPE, requestedContentType.toContentTypeString());
@@ -552,7 +550,7 @@ public class TechnicalEntityProcessor extends TechnicalProcessor
   }
 
   // just for demonstration
-  private SerializerResult serializeEntityStreamCollectionFixed(final ODataRequest request,
+  private SerializerStreamResult serializeEntityStreamCollectionFixed(final ODataRequest request,
       final EntityCollection entityCollection, final EdmEntitySet edmEntitySet,
       final EdmEntityType edmEntityType,
       final ContentType requestedFormat, final ExpandOption expand, final SelectOption select,
@@ -630,7 +628,7 @@ public class TechnicalEntityProcessor extends TechnicalProcessor
 
     };
 
-    return odata.createSerializer(requestedFormat).entityCollection(
+    return odata.createSerializer(requestedFormat).entityCollectionStreamed(
         serviceMetadata,
         edmEntityType,
         streamCollection,