Java tutorial
/** * */ package com.thinkbiganalytics.metadata.core.dataset; /*- * #%L * thinkbig-metadata-core * %% * Copyright (C) 2017 ThinkBig Analytics * %% * Licensed 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. * #L% */ import com.google.common.base.Predicate; import com.google.common.collect.Iterators; import com.google.common.collect.Lists; import com.thinkbiganalytics.metadata.api.MetadataException; import com.thinkbiganalytics.metadata.api.datasource.Datasource; import com.thinkbiganalytics.metadata.api.datasource.Datasource.ID; import com.thinkbiganalytics.metadata.api.datasource.DatasourceCriteria; import com.thinkbiganalytics.metadata.api.datasource.DatasourceDetails; import com.thinkbiganalytics.metadata.api.datasource.DatasourceProvider; import com.thinkbiganalytics.metadata.api.datasource.DerivedDatasource; import com.thinkbiganalytics.metadata.core.AbstractMetadataCriteria; import org.apache.commons.lang3.reflect.ConstructorUtils; import org.joda.time.DateTime; import java.io.Serializable; import java.lang.reflect.InvocationTargetException; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.Optional; import java.util.concurrent.ConcurrentHashMap; import javax.annotation.Nonnull; /** * */ public class InMemoryDatasourceProvider implements DatasourceProvider { private Map<Datasource.ID, Datasource> datasets = new ConcurrentHashMap<>(); public DatasourceCriteria datasetCriteria() { return new DatasetCriteriaImpl(); } @Override public ID resolve(Serializable id) { if (id instanceof BaseDatasource.DatasourceId) { return (BaseDatasource.DatasourceId) id; } else { return new BaseDatasource.DatasourceId(id); } } @Override public DerivedDatasource ensureDerivedDatasource(String datasourceType, String identityString, String title, String desc, Map<String, Object> properties) { return null; } @Override public DerivedDatasource findDerivedDatasource(String datasourceType, String systemName) { return null; } @Override public <D extends Datasource> D ensureDatasource(String name, String descr, Class<D> type) { synchronized (this.datasets) { try { D ds = null; BaseDatasource existing = getExistingDataset(name); if (existing == null) { ds = (D) ConstructorUtils.invokeConstructor(type, name, descr); this.datasets.put(ds.getId(), ds); } else if (type.isInstance(ds)) { ds = (D) existing; } else { throw new MetadataException("A datasource already exists of type: " + ds.getClass() + " but expected one of type: " + type); } return ds; } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException | InstantiationException e) { throw new MetadataException("Failed to create a datasource to type: " + type, e); } } } @Override public DerivedDatasource ensureGenericDatasource(String name, String descr) { return null; } // // @Override public Datasource ensureDatasource(String name, String descr) { synchronized (this.datasets) { BaseDatasource ds = getExistingDataset(name); if (ds == null) { ds = new BaseDatasource(name, descr); this.datasets.put(ds.getId(), ds); } return ds; } } @Override public void removeDatasource(ID id) { } // // // @Override // public DirectoryDatasource asDirectoryDatasource(ID dsId, Path dir) { // synchronized (this.datasets) { // BaseDatasource ds = (BaseDatasource) this.datasets.get(dsId); // // if (ds != null) { // BaseDirectoryDatasource dds = new BaseDirectoryDatasource(ds, dir); // this.datasets.put(dds.getId(), dds); // return dds; // } else { // throw new DatasourceException("A no dataset exists with the given ID: " + dsId); // } // } // } // // @Override // public HiveTableDatasource asHiveTableDatasource(ID dsId, String database, String table) { // synchronized (this.datasets) { // BaseDatasource ds = (BaseDatasource) this.datasets.get(dsId); // // if (ds != null) { // BaseHiveTableDatasource hds = new BaseHiveTableDatasource(ds, database, table); // this.datasets.put(hds.getId(), hds); // return hds; // } else { // throw new DatasourceException("A no dataset exists with the given ID: " + dsId); // } // } // } @Override public Datasource getDatasource(ID id) { return this.datasets.get(id); } @Override public List<Datasource> getDatasources() { return new ArrayList<Datasource>(this.datasets.values()); } @Override public List<Datasource> getDatasources(DatasourceCriteria criteria) { // TODO replace cast with copy method DatasetCriteriaImpl critImpl = (DatasetCriteriaImpl) criteria; Iterator<Datasource> filtered = Iterators.filter(this.datasets.values().iterator(), critImpl); Iterator<Datasource> limited = Iterators.limit(filtered, critImpl.getLimit()); List<Datasource> list = Lists.newArrayList(limited); Collections.sort(list, critImpl); return list; } @Override public <D extends DatasourceDetails> Optional<D> ensureDatasourceDetails(@Nonnull ID id, @Nonnull Class<D> type) { return null; } private BaseDatasource getExistingDataset(String name) { synchronized (this.datasets) { for (Datasource ds : this.datasets.values()) { if (ds.getName().equals(name)) { return (BaseDatasource) ds; } } return null; } } private static class DatasetCriteriaImpl extends AbstractMetadataCriteria<DatasourceCriteria> implements DatasourceCriteria, Predicate<Datasource>, Comparator<Datasource> { private String name; private DateTime createdOn; private DateTime createdAfter; private DateTime createdBefore; private Class<? extends Datasource> type; @Override public boolean apply(Datasource input) { if (this.type != null && !this.type.isAssignableFrom(input.getClass())) { return false; } if (this.name != null && !name.equals(input.getName())) { return false; } if (this.createdOn != null && !this.createdOn.equals(input.getCreatedTime())) { return false; } if (this.createdAfter != null && !this.createdAfter.isBefore(input.getCreatedTime())) { return false; } if (this.createdBefore != null && !this.createdBefore.isBefore(input.getCreatedTime())) { return false; } return true; } @Override public int compare(Datasource o1, Datasource o2) { return o2.getCreatedTime().compareTo(o1.getCreatedTime()); } @Override public DatasourceCriteria name(String name) { this.name = name; return this; } @Override public DatasourceCriteria createdOn(DateTime time) { this.createdOn = time; return this; } @Override public DatasourceCriteria createdAfter(DateTime time) { this.createdAfter = time; return this; } @Override public DatasourceCriteria createdBefore(DateTime time) { this.createdBefore = time; return this; } @Override public DatasourceCriteria type(Class<? extends Datasource> type) { this.type = type; return this; } } }