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.fit.metadata; import java.io.InputStream; import java.util.Collection; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import javax.xml.namespace.QName; import javax.xml.stream.XMLEventReader; import javax.xml.stream.XMLInputFactory; import javax.xml.stream.XMLStreamException; import javax.xml.stream.events.Attribute; import javax.xml.stream.events.StartElement; import javax.xml.stream.events.XMLEvent; import org.apache.commons.io.IOUtils; import org.apache.commons.lang3.BooleanUtils; import org.apache.commons.lang3.StringUtils; import org.apache.olingo.fit.utils.ConstantKey; import org.apache.olingo.fit.utils.Constants; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class Metadata extends AbstractMetadataElement { /** * Logger. */ protected static final Logger LOG = LoggerFactory.getLogger(Metadata.class); private final Map<String, Schema> schemas; private final String DEF_NS; public Metadata(final InputStream is) { DEF_NS = Constants.get(ConstantKey.EDM_NS); schemas = new HashMap<String, Schema>(); try { final XMLInputFactory ifactory = XMLInputFactory.newInstance(); final XMLEventReader reader = ifactory.createXMLEventReader(is, org.apache.olingo.commons.api.Constants.UTF8); try { while (reader.hasNext()) { final XMLEvent event = reader.nextEvent(); if (event.isStartElement() && event.asStartElement().getName().equals(new QName(DEF_NS, "Schema"))) { final Schema schema = getSchema(event.asStartElement(), reader); schemas.put(schema.getNamespace(), schema); } } } catch (Exception ignore) { // ignore } finally { reader.close(); IOUtils.closeQuietly(is); } } catch (Exception e) { LOG.error("Error parsing metadata", e); } for (Map.Entry<String, Schema> schemaEntry : schemas.entrySet()) { for (EntityType entityType : schemaEntry.getValue().getEntityTypes()) { for (NavigationProperty property : entityType.getNavigationProperties()) { property.setFeed(property.getType().startsWith("Collection(")); final Collection<EntitySet> entitySets = schemaEntry.getValue().getContainers().iterator() .next().getEntitySets(schemaEntry.getKey(), entityType.getName()); final Iterator<EntitySet> iter = entitySets.iterator(); boolean found = false; while (!found && iter.hasNext()) { final EntitySet entitySet = iter.next(); final String target = entitySet.getTarget(property.getName()); if (StringUtils.isNotBlank(target)) { property.setTarget(entitySet.getTarget(property.getName())); found = true; } } } } } } public EntitySet getEntitySet(final String name) { for (Schema schema : getSchemas()) { for (Container container : schema.getContainers()) { final EntitySet entitySet = container.getEntitySet(name); if (entitySet != null) { return entitySet; } } } return null; } public EntityType getEntityOrComplexType(final String fqn) { EntityType result = null; final String ns = StringUtils.substringBeforeLast(fqn, "."); if (getSchema(ns) != null) { final String name = StringUtils.substringAfterLast(fqn, "."); result = getSchema(ns).getEntityType(name); if (result != null && result.getBaseType() != null) { final String baseNS = StringUtils.substringBeforeLast(result.getBaseType(), "."); if (getSchema(baseNS) != null) { final String baseName = StringUtils.substringAfterLast(result.getBaseType(), "."); final EntityType baseType = getSchema(baseNS).getEntityType(baseName); if (baseType != null) { for (Map.Entry<String, Property> entry : baseType.getPropertyMap().entrySet()) { result.addProperty(entry.getKey(), entry.getValue()); } for (Map.Entry<String, NavigationProperty> entry : baseType.getNavigationPropertyMap() .entrySet()) { result.addNavigationProperty(entry.getKey(), entry.getValue()); } } } } } return result; } public Map<String, NavigationProperty> getNavigationProperties(final String entitySetName) { for (Schema schema : getSchemas()) { for (Container container : schema.getContainers()) { final EntitySet entitySet = container.getEntitySet(entitySetName); if (entitySet != null) { final String entityTypeFQN = entitySet.getType(); final int lastDotIndex = entityTypeFQN.lastIndexOf('.'); final String entityTypeNS = entityTypeFQN.substring(0, lastDotIndex); final String entityTypeName = entityTypeFQN.substring(lastDotIndex + 1); final EntityType entityType = getSchema(entityTypeNS).getEntityType(entityTypeName); return entityType.getNavigationPropertyMap(); } } } return null; } public Collection<Schema> getSchemas() { return schemas.values(); } public Schema getSchema(final String namespace) { return schemas.get(namespace); } public Metadata addSchema(final String namespace, final Schema schema) { schemas.put(namespace, schema); return this; } private Schema getSchema(final StartElement start, final XMLEventReader reader) throws XMLStreamException { final Schema schema = new Schema(start.getAttributeByName(new QName("Namespace")).getValue()); boolean completed = false; while (!completed && reader.hasNext()) { XMLEvent event = reader.nextEvent(); if (event.isStartElement() && event.asStartElement().getName().equals(new QName(DEF_NS, "EntityType")) || event.isStartElement() && event.asStartElement().getName().equals(new QName(DEF_NS, "ComplexType"))) { final EntityType entityType = getEntityType(event.asStartElement(), reader); schema.addEntityType(entityType.getName(), entityType); } else if (event.isStartElement() && event.asStartElement().getName().equals(new QName(DEF_NS, "EntityContainer"))) { final org.apache.olingo.fit.metadata.Container container = getContainer(event.asStartElement(), reader); schema.addContainer(container.getName(), container); } else if (event.isEndElement() && event.asEndElement().getName().equals(start.getName())) { completed = true; } } return schema; } private org.apache.olingo.fit.metadata.Container getContainer(final StartElement start, final XMLEventReader reader) throws XMLStreamException { final org.apache.olingo.fit.metadata.Container container = new org.apache.olingo.fit.metadata.Container( start.getAttributeByName(new QName("Name")).getValue()); boolean completed = false; while (!completed && reader.hasNext()) { XMLEvent event = reader.nextEvent(); if (event.isStartElement() && (event.asStartElement().getName().equals(new QName(DEF_NS, "EntitySet")) || event.asStartElement().getName().equals(new QName(DEF_NS, "Singleton")))) { final EntitySet entitySet = getEntitySet(event.asStartElement(), reader); container.addEntitySet(entitySet.getName(), entitySet); } else if (event.isEndElement() && event.asEndElement().getName().equals(start.getName())) { completed = true; } } return container; } private EntityType getEntityType(final StartElement start, final XMLEventReader reader) throws XMLStreamException { final EntityType entityType = new EntityType(start.getAttributeByName(new QName("Name")).getValue()); final Attribute baseType = start.getAttributeByName(new QName("BaseType")); if (baseType != null) { entityType.setBaseType(baseType.getValue()); } final Attribute openType = start.getAttributeByName(new QName("OpenType")); if (openType != null) { entityType.setOpenType(BooleanUtils.toBoolean(openType.getValue())); } boolean completed = false; while (!completed && reader.hasNext()) { XMLEvent event = reader.nextEvent(); if (event.isStartElement() && event.asStartElement().getName().equals(new QName(DEF_NS, "Property"))) { final org.apache.olingo.fit.metadata.Property property = getProperty(event.asStartElement()); entityType.addProperty(property.getName(), property); } else if (event.isStartElement() && event.asStartElement().getName().equals(new QName(DEF_NS, "NavigationProperty"))) { final NavigationProperty property = getNavigationProperty(event.asStartElement()); entityType.addNavigationProperty(property.getName(), property); } else if (event.isEndElement() && event.asEndElement().getName().equals(start.getName())) { completed = true; } } return entityType; } private org.apache.olingo.fit.metadata.Property getProperty(final StartElement start) throws XMLStreamException { final org.apache.olingo.fit.metadata.Property property = new org.apache.olingo.fit.metadata.Property( start.getAttributeByName(new QName("Name")).getValue()); final Attribute type = start.getAttributeByName(new QName("Type")); property.setType(type == null ? "Edm.String" : type.getValue()); final Attribute nullable = start.getAttributeByName(new QName("Nullable")); property.setNullable(nullable == null || !"false".equals(nullable.getValue())); return property; } private NavigationProperty getNavigationProperty(final StartElement start) throws XMLStreamException { final NavigationProperty property = new NavigationProperty( start.getAttributeByName(new QName("Name")).getValue()); final Attribute type = start.getAttributeByName(new QName("Type")); if (type != null) { property.setType(type.getValue()); } return property; } private EntitySet getEntitySet(final StartElement start, final XMLEventReader reader) throws XMLStreamException { final EntitySet entitySet = "Singleton".equals(start.getName().getLocalPart()) ? new EntitySet(start.getAttributeByName(new QName("Name")).getValue(), true) : new EntitySet(start.getAttributeByName(new QName("Name")).getValue()); Attribute type = start.getAttributeByName(new QName("EntityType")); if (type == null) { type = start.getAttributeByName(new QName("Type")); entitySet.setType(type == null ? null : type.getValue()); } else { entitySet.setType(type.getValue()); } boolean completed = false; while (!completed && reader.hasNext()) { XMLEvent event = reader.nextEvent(); if (event.isStartElement() && event.asStartElement().getName().equals(new QName(DEF_NS, "NavigationPropertyBinding"))) { final String path = event.asStartElement().getAttributeByName(new QName("Path")).getValue(); final String target = event.asStartElement().getAttributeByName(new QName("Target")).getValue(); entitySet.addBinding(path, target); } else if (event.isEndElement() && event.asEndElement().getName().equals(start.getName())) { completed = true; } } return entitySet; } }