Java tutorial
/* * 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.commons.core.serialization; import com.fasterxml.aalto.stax.OutputFactoryImpl; import org.apache.commons.lang3.StringUtils; import org.apache.olingo.commons.api.Constants; import org.apache.olingo.commons.api.data.Annotation; import org.apache.olingo.commons.api.data.ContextURL; import org.apache.olingo.commons.api.data.Entity; import org.apache.olingo.commons.api.data.EntitySet; import org.apache.olingo.commons.api.data.Link; import org.apache.olingo.commons.api.data.LinkedComplexValue; import org.apache.olingo.commons.api.data.Property; import org.apache.olingo.commons.api.data.ResWrap; import org.apache.olingo.commons.api.data.ValueType; import org.apache.olingo.commons.api.domain.ODataOperation; import org.apache.olingo.commons.api.edm.EdmPrimitiveTypeException; import org.apache.olingo.commons.api.edm.EdmPrimitiveTypeKind; import org.apache.olingo.commons.api.edm.constants.ODataServiceVersion; import org.apache.olingo.commons.api.edm.constants.ODataServiceVersion.NamespaceKey; import org.apache.olingo.commons.api.edm.geo.Geospatial; import org.apache.olingo.commons.api.format.ContentType; import org.apache.olingo.commons.api.serialization.ODataSerializer; import org.apache.olingo.commons.api.serialization.ODataSerializerException; import org.apache.olingo.commons.core.data.AbstractODataObject; import org.apache.olingo.commons.core.data.EntityImpl; import org.apache.olingo.commons.core.data.EntitySetImpl; import org.apache.olingo.commons.core.data.LinkImpl; import org.apache.olingo.commons.core.edm.EdmTypeInfo; import org.apache.olingo.commons.core.edm.primitivetype.EdmPrimitiveTypeFactory; import javax.xml.XMLConstants; import javax.xml.stream.XMLOutputFactory; import javax.xml.stream.XMLStreamException; import javax.xml.stream.XMLStreamWriter; import java.io.Writer; import java.util.Collections; import java.util.List; public class AtomSerializer extends AbstractAtomDealer implements ODataSerializer { private static final XMLOutputFactory FACTORY = new OutputFactoryImpl(); private final AtomGeoValueSerializer geoSerializer; private final boolean serverMode; public AtomSerializer(final ODataServiceVersion version) { this(version, false); } public AtomSerializer(final ODataServiceVersion version, final boolean serverMode) { super(version); geoSerializer = new AtomGeoValueSerializer(); this.serverMode = serverMode; } private void collection(final XMLStreamWriter writer, final ValueType valueType, final EdmPrimitiveTypeKind kind, final List<?> value) throws XMLStreamException, EdmPrimitiveTypeException { for (Object item : value) { if (version.compareTo(ODataServiceVersion.V40) < 0) { writer.writeStartElement(Constants.PREFIX_DATASERVICES, Constants.ELEM_ELEMENT, namespaceData); } else { writer.writeStartElement(Constants.PREFIX_METADATA, Constants.ELEM_ELEMENT, namespaceMetadata); } value(writer, valueType, kind, item); writer.writeEndElement(); } } @SuppressWarnings("unchecked") private void value(final XMLStreamWriter writer, final ValueType valueType, final EdmPrimitiveTypeKind kind, final Object value) throws XMLStreamException, EdmPrimitiveTypeException { if (value == null) { writer.writeAttribute(Constants.PREFIX_METADATA, namespaceMetadata, Constants.ATTR_NULL, Boolean.TRUE.toString()); return; } switch (valueType) { case PRIMITIVE: writer.writeCharacters(kind == null ? value.toString() : EdmPrimitiveTypeFactory.getInstance(kind) // TODO: add facets .valueToString(value, null, null, Constants.DEFAULT_PRECISION, Constants.DEFAULT_SCALE, null)); break; case ENUM: writer.writeCharacters(value.toString()); break; case GEOSPATIAL: geoSerializer.serialize(writer, (Geospatial) value); break; case COLLECTION_PRIMITIVE: case COLLECTION_GEOSPATIAL: case COLLECTION_ENUM: case COLLECTION_COMPLEX: case COLLECTION_LINKED_COMPLEX: collection(writer, valueType.getBaseType(), kind, (List<?>) value); break; case LINKED_COMPLEX: for (Property property : ((LinkedComplexValue) value).getValue()) { property(writer, property, false); } break; case COMPLEX: for (Property property : (List<Property>) value) { property(writer, property, false); } break; } } public void property(final XMLStreamWriter writer, final Property property, final boolean standalone) throws XMLStreamException, EdmPrimitiveTypeException { if (version.compareTo(ODataServiceVersion.V40) >= 0 && standalone) { writer.writeStartElement(Constants.PREFIX_METADATA, Constants.VALUE, namespaceData); } else { writer.writeStartElement(Constants.PREFIX_DATASERVICES, property.getName(), namespaceData); } if (standalone) { namespaces(writer); } EdmTypeInfo typeInfo = null; if (StringUtils.isNotBlank(property.getType())) { typeInfo = new EdmTypeInfo.Builder().setTypeExpression(property.getType()).build(); if (!EdmPrimitiveTypeKind.String.getFullQualifiedName().toString().equals(typeInfo.internal())) { writer.writeAttribute(Constants.PREFIX_METADATA, namespaceMetadata, Constants.ATTR_TYPE, typeInfo.external(version)); } } value(writer, property.getValueType(), typeInfo == null ? null : typeInfo.getPrimitiveTypeKind(), property.getValue()); if (!property.isNull() && property.isLinkedComplex()) { links(writer, property.asLinkedComplex().getAssociationLinks()); links(writer, property.asLinkedComplex().getNavigationLinks()); } writer.writeEndElement(); for (Annotation annotation : property.getAnnotations()) { annotation(writer, annotation, property.getName()); } } private void property(final XMLStreamWriter writer, final Property property) throws XMLStreamException, EdmPrimitiveTypeException { property(writer, property, true); } private void startDocument(final XMLStreamWriter writer, final String rootElement) throws XMLStreamException { writer.writeStartDocument(); writer.setDefaultNamespace(Constants.NS_ATOM); writer.writeStartElement(rootElement); namespaces(writer); } private void property(final Writer outWriter, final Property property) throws XMLStreamException, EdmPrimitiveTypeException { final XMLStreamWriter writer = FACTORY.createXMLStreamWriter(outWriter); writer.writeStartDocument(); property(writer, property); writer.writeEndDocument(); writer.flush(); } private void links(final XMLStreamWriter writer, final List<Link> links) throws XMLStreamException, EdmPrimitiveTypeException { for (Link link : links) { writer.writeStartElement(Constants.ATOM_ELEM_LINK); if (StringUtils.isNotBlank(link.getRel())) { writer.writeAttribute(Constants.ATTR_REL, link.getRel()); } if (StringUtils.isNotBlank(link.getTitle())) { writer.writeAttribute(Constants.ATTR_TITLE, link.getTitle()); } if (StringUtils.isNotBlank(link.getHref())) { writer.writeAttribute(Constants.ATTR_HREF, link.getHref()); } if (StringUtils.isNotBlank(link.getType())) { writer.writeAttribute(Constants.ATTR_TYPE, link.getType()); } if (link.getInlineEntity() != null || link.getInlineEntitySet() != null) { writer.writeStartElement(Constants.PREFIX_METADATA, Constants.ATOM_ELEM_INLINE, namespaceMetadata); if (link.getInlineEntity() != null) { writer.writeStartElement(Constants.ATOM_ELEM_ENTRY); entity(writer, link.getInlineEntity()); writer.writeEndElement(); } if (link.getInlineEntitySet() != null) { writer.writeStartElement(Constants.ATOM_ELEM_FEED); entitySet(writer, link.getInlineEntitySet()); writer.writeEndElement(); } writer.writeEndElement(); } for (Annotation annotation : link.getAnnotations()) { annotation(writer, annotation, null); } writer.writeEndElement(); } } private void common(final XMLStreamWriter writer, final AbstractODataObject object) throws XMLStreamException { if (StringUtils.isNotBlank(object.getTitle())) { writer.writeStartElement(Constants.ATOM_ELEM_TITLE); writer.writeAttribute(Constants.ATTR_TYPE, TYPE_TEXT); writer.writeCharacters(object.getTitle()); writer.writeEndElement(); } } private void properties(final XMLStreamWriter writer, final List<Property> properties) throws XMLStreamException, EdmPrimitiveTypeException { for (Property property : properties) { property(writer, property, false); } } private void annotation(final XMLStreamWriter writer, final Annotation annotation, final String target) throws XMLStreamException, EdmPrimitiveTypeException { writer.writeStartElement(Constants.PREFIX_METADATA, Constants.ANNOTATION, namespaceMetadata); writer.writeAttribute(Constants.ATOM_ATTR_TERM, annotation.getTerm()); if (target != null) { writer.writeAttribute(Constants.ATTR_TARGET, target); } EdmTypeInfo typeInfo = null; if (StringUtils.isNotBlank(annotation.getType())) { typeInfo = new EdmTypeInfo.Builder().setTypeExpression(annotation.getType()).build(); if (!EdmPrimitiveTypeKind.String.getFullQualifiedName().toString().equals(typeInfo.internal())) { writer.writeAttribute(Constants.PREFIX_METADATA, namespaceMetadata, Constants.ATTR_TYPE, typeInfo.external(version)); } } value(writer, annotation.getValueType(), typeInfo == null ? null : typeInfo.getPrimitiveTypeKind(), annotation.getValue()); writer.writeEndElement(); } private void entity(final XMLStreamWriter writer, final Entity entity) throws XMLStreamException, EdmPrimitiveTypeException { if (entity.getBaseURI() != null) { writer.writeAttribute(XMLConstants.XML_NS_URI, Constants.ATTR_XML_BASE, entity.getBaseURI().toASCIIString()); } if (serverMode && StringUtils.isNotBlank(entity.getETag())) { writer.writeAttribute(namespaceMetadata, Constants.ATOM_ATTR_ETAG, entity.getETag()); } if (entity.getId() != null) { writer.writeStartElement(Constants.ATOM_ELEM_ID); writer.writeCharacters(entity.getId().toASCIIString()); writer.writeEndElement(); } writer.writeStartElement(Constants.ATOM_ELEM_CATEGORY); writer.writeAttribute(Constants.ATOM_ATTR_SCHEME, version.getNamespace(ODataServiceVersion.NamespaceKey.SCHEME)); if (StringUtils.isNotBlank(entity.getType())) { writer.writeAttribute(Constants.ATOM_ATTR_TERM, new EdmTypeInfo.Builder().setTypeExpression(entity.getType()).build().external(version)); } writer.writeEndElement(); if (entity instanceof AbstractODataObject) { common(writer, (AbstractODataObject) entity); } if (serverMode) { if (entity.getEditLink() != null) { links(writer, Collections.singletonList(entity.getEditLink())); } if (entity.getSelfLink() != null) { links(writer, Collections.singletonList(entity.getSelfLink())); } } links(writer, entity.getAssociationLinks()); links(writer, entity.getNavigationLinks()); links(writer, entity.getMediaEditLinks()); if (serverMode) { for (ODataOperation operation : entity.getOperations()) { writer.writeStartElement(namespaceMetadata, Constants.ATOM_ELEM_ACTION); writer.writeAttribute(Constants.ATTR_METADATA, operation.getMetadataAnchor()); writer.writeAttribute(Constants.ATTR_TITLE, operation.getTitle()); writer.writeAttribute(Constants.ATTR_TARGET, operation.getTarget().toASCIIString()); writer.writeEndElement(); } } writer.writeStartElement(Constants.ATOM_ELEM_CONTENT); if (entity.isMediaEntity()) { if (StringUtils.isNotBlank(entity.getMediaContentType())) { writer.writeAttribute(Constants.ATTR_TYPE, entity.getMediaContentType()); } if (entity.getMediaContentSource() != null) { writer.writeAttribute(Constants.ATOM_ATTR_SRC, entity.getMediaContentSource().toASCIIString()); } writer.writeEndElement(); writer.writeStartElement(namespaceMetadata, Constants.PROPERTIES); properties(writer, entity.getProperties()); } else { writer.writeAttribute(Constants.ATTR_TYPE, ContentType.APPLICATION_XML.toContentTypeString()); writer.writeStartElement(namespaceMetadata, Constants.PROPERTIES); properties(writer, entity.getProperties()); writer.writeEndElement(); } writer.writeEndElement(); for (Annotation annotation : entity.getAnnotations()) { annotation(writer, annotation, null); } } private void entityRef(final XMLStreamWriter writer, final Entity entity) throws XMLStreamException { writer.writeStartElement(Constants.ATOM_ELEM_ENTRY_REF); writer.writeNamespace(StringUtils.EMPTY, namespaceMetadata); writer.writeAttribute(Constants.ATOM_ATTR_ID, entity.getId().toASCIIString()); } private void entityRef(final XMLStreamWriter writer, final ResWrap<Entity> container) throws XMLStreamException { writer.writeStartElement(Constants.ATOM_ELEM_ENTRY_REF); writer.writeNamespace(StringUtils.EMPTY, namespaceMetadata); addContextInfo(writer, container); writer.writeAttribute(Constants.ATOM_ATTR_ID, container.getPayload().getId().toASCIIString()); } private void entity(final Writer outWriter, final Entity entity) throws XMLStreamException, EdmPrimitiveTypeException { final XMLStreamWriter writer = FACTORY.createXMLStreamWriter(outWriter); if (entity.getType() == null && entity.getProperties().isEmpty()) { writer.writeStartDocument(); writer.setDefaultNamespace(namespaceMetadata); entityRef(writer, entity); } else { startDocument(writer, Constants.ATOM_ELEM_ENTRY); entity(writer, entity); } writer.writeEndElement(); writer.writeEndDocument(); writer.flush(); } private void entity(final Writer outWriter, final ResWrap<Entity> container) throws XMLStreamException, EdmPrimitiveTypeException { final Entity entity = container.getPayload(); final XMLStreamWriter writer = FACTORY.createXMLStreamWriter(outWriter); if (entity.getType() == null && entity.getProperties().isEmpty()) { writer.writeStartDocument(); writer.setDefaultNamespace(namespaceMetadata); entityRef(writer, container); } else { startDocument(writer, Constants.ATOM_ELEM_ENTRY); addContextInfo(writer, container); entity(writer, entity); } writer.writeEndElement(); writer.writeEndDocument(); writer.flush(); } private void entitySet(final XMLStreamWriter writer, final EntitySet entitySet) throws XMLStreamException, EdmPrimitiveTypeException { if (entitySet.getBaseURI() != null) { writer.writeAttribute(XMLConstants.XML_NS_URI, Constants.ATTR_XML_BASE, entitySet.getBaseURI().toASCIIString()); } if (entitySet.getCount() != null) { writer.writeStartElement(namespaceMetadata, Constants.ATOM_ELEM_COUNT); writer.writeCharacters(Integer.toString(entitySet.getCount())); writer.writeEndElement(); } if (entitySet.getId() != null) { writer.writeStartElement(Constants.ATOM_ELEM_ID); writer.writeCharacters(entitySet.getId().toASCIIString()); writer.writeEndElement(); } if (entitySet instanceof AbstractODataObject) { common(writer, (AbstractODataObject) entitySet); } for (Entity entity : entitySet.getEntities()) { if (entity.getType() == null && entity.getProperties().isEmpty()) { entityRef(writer, entity); writer.writeEndElement(); } else { writer.writeStartElement(Constants.ATOM_ELEM_ENTRY); entity(writer, entity); writer.writeEndElement(); } } if (serverMode) { if (entitySet.getNext() != null) { final LinkImpl next = new LinkImpl(); next.setRel(Constants.NEXT_LINK_REL); next.setHref(entitySet.getNext().toASCIIString()); links(writer, Collections.<Link>singletonList(next)); } if (entitySet.getDeltaLink() != null) { final LinkImpl next = new LinkImpl(); next.setRel(ODataServiceVersion.V40.getNamespace(NamespaceKey.DELTA_LINK_REL)); next.setHref(entitySet.getDeltaLink().toASCIIString()); links(writer, Collections.<Link>singletonList(next)); } } } private void entitySet(final Writer outWriter, final EntitySet entitySet) throws XMLStreamException, EdmPrimitiveTypeException { final XMLStreamWriter writer = FACTORY.createXMLStreamWriter(outWriter); startDocument(writer, Constants.ATOM_ELEM_FEED); entitySet(writer, entitySet); writer.writeEndElement(); writer.writeEndDocument(); writer.flush(); } private void entitySet(final Writer outWriter, final ResWrap<EntitySet> entitySet) throws XMLStreamException, EdmPrimitiveTypeException { final XMLStreamWriter writer = FACTORY.createXMLStreamWriter(outWriter); startDocument(writer, Constants.ATOM_ELEM_FEED); addContextInfo(writer, entitySet); entitySet(writer, entitySet.getPayload()); writer.writeEndElement(); writer.writeEndDocument(); writer.flush(); } private void link(final Writer outWriter, final Link link) throws XMLStreamException { final XMLStreamWriter writer = FACTORY.createXMLStreamWriter(outWriter); writer.writeStartDocument(); writer.writeStartElement(Constants.ELEM_LINKS); writer.writeDefaultNamespace(namespaceData); writer.writeStartElement(Constants.ELEM_URI); writer.writeCharacters(link.getHref()); writer.writeEndElement(); writer.writeEndElement(); writer.writeEndDocument(); writer.flush(); } @Override public <T> void write(final Writer writer, final T obj) throws ODataSerializerException { try { if (obj instanceof EntitySet) { entitySet(writer, (EntitySet) obj); } else if (obj instanceof Entity) { entity(writer, (Entity) obj); } else if (obj instanceof Property) { property(writer, (Property) obj); } else if (obj instanceof Link) { link(writer, (Link) obj); } } catch (final XMLStreamException e) { throw new ODataSerializerException(e); } catch (final EdmPrimitiveTypeException e) { throw new ODataSerializerException(e); } } @Override @SuppressWarnings("unchecked") public <T> void write(final Writer writer, final ResWrap<T> container) throws ODataSerializerException { final T obj = container == null ? null : container.getPayload(); try { if (obj instanceof EntitySet) { this.entitySet(writer, (ResWrap<EntitySet>) container); } else if (obj instanceof Entity) { entity(writer, (ResWrap<Entity>) container); } else if (obj instanceof Property) { property(writer, (Property) obj); } else if (obj instanceof Link) { link(writer, (Link) obj); } } catch (final XMLStreamException e) { throw new ODataSerializerException(e); } catch (final EdmPrimitiveTypeException e) { throw new ODataSerializerException(e); } } private <T> void addContextInfo(final XMLStreamWriter writer, final ResWrap<T> container) throws XMLStreamException { if (container.getContextURL() != null) { final ContextURL contextURL = ContextURLParser.parse(container.getContextURL()); String base = contextURL.getServiceRoot().toASCIIString(); if (container.getPayload() instanceof EntitySet) { ((EntitySetImpl) container.getPayload()).setBaseURI(base); } if (container.getPayload() instanceof Entity) { ((EntityImpl) container.getPayload()).setBaseURI(base); } writer.writeAttribute(namespaceMetadata, Constants.CONTEXT, container.getContextURL().toASCIIString()); } if (StringUtils.isNotBlank(container.getMetadataETag())) { writer.writeAttribute(namespaceMetadata, Constants.ATOM_ATTR_METADATAETAG, container.getMetadataETag()); } } }