Java tutorial
/******************************************************************************* * Copyright 2015, The IKANOW Open Source Project. * * 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. *******************************************************************************/ package com.ikanow.aleph2.shared.crud.mongodb.utils; import java.io.IOException; import java.util.Arrays; import java.util.Collection; import java.util.Map; import java.util.Optional; import java.util.stream.Collector; import java.util.stream.Collectors; import java.util.stream.Collector.Characteristics; import org.mongojack.internal.MongoJackModule; import org.mongojack.internal.object.BsonObjectGenerator; import scala.Tuple2; import com.fasterxml.jackson.core.JsonGenerationException; import com.fasterxml.jackson.databind.JsonMappingException; import com.fasterxml.jackson.databind.JsonNode; import com.fasterxml.jackson.databind.ObjectMapper; import com.google.common.collect.LinkedHashMultimap; import com.google.common.collect.Maps; import com.ikanow.aleph2.data_model.utils.BeanTemplateUtils.BeanTemplate; import com.ikanow.aleph2.data_model.utils.CrudUtils.UpdateOperator; import com.ikanow.aleph2.data_model.utils.BeanTemplateUtils; import com.ikanow.aleph2.data_model.utils.Patterns; import com.ikanow.aleph2.data_model.utils.Tuples; import com.ikanow.aleph2.data_model.utils.CrudUtils.MultiQueryComponent; import com.ikanow.aleph2.data_model.utils.CrudUtils.Operator; import com.ikanow.aleph2.data_model.utils.CrudUtils.QueryComponent; import com.ikanow.aleph2.data_model.utils.CrudUtils.SingleQueryComponent; import com.ikanow.aleph2.data_model.utils.CrudUtils.UpdateComponent; import com.mongodb.BasicDBList; import com.mongodb.BasicDBObject; import com.mongodb.DBObject; import com.mongodb.QueryBuilder; /** Utilities for converting from generic CRUD commands to MongoDB * @author acp */ public class MongoDbUtils { //////////////////////////////////////////////////////////////////////////////////////// // CREATE QUERY /** Top-level entry point to convert a generic Aleph2 CRUD component into a function MongoDB query * @param query_in the generic query component * @return a tuple2, first element is the query, second element contains the meta ("$skip", "$limit") */ @SuppressWarnings("unchecked") public static <T> Tuple2<DBObject, DBObject> convertToMongoQuery(final QueryComponent<T> query_in) { final String andVsOr = getOperatorName(query_in.getOp()); final DBObject query_out = Patterns.match(query_in).<DBObject>andReturn() .when((Class<SingleQueryComponent<T>>) (Class<?>) SingleQueryComponent.class, q -> convertToMongoQuery_single(andVsOr, q)) .when((Class<MultiQueryComponent<T>>) (Class<?>) MultiQueryComponent.class, q -> convertToMongoQuery_multi(andVsOr, q)) .otherwise(() -> (DBObject) new BasicDBObject()); // Meta commands final BasicDBObject meta = new BasicDBObject(); if (null != query_in.getLimit()) meta.put("$limit", query_in.getLimit()); final BasicDBObject sort = Patterns.match(query_in.getOrderBy()).<BasicDBObject>andReturn() .when(l -> l == null, l -> null).otherwise(l -> { BasicDBObject s = new BasicDBObject(); l.stream().forEach(field_order -> s.put(field_order._1(), field_order._2())); return s; }); if (null != sort) meta.put("$sort", sort); return Tuples._2T(query_out, meta); } ////////////////////////////////////////////////////////////////////// // UTILS /** Creates the MongoDB clause from the QueryComponent inner object * @param field - the field used in the clause * @param operator_args - an operator enum and a pair of objects whose context depends on the operator * @return the MongoDB clause */ protected static BasicDBObject operatorToMongoKey(final String field, final Tuple2<Operator, Tuple2<Object, Object>> operator_args) { return Patterns.match(operator_args).<BasicDBObject>andReturn() .when(op_args -> Operator.exists == op_args._1(), op_args -> new BasicDBObject(field, new BasicDBObject("$exists", op_args._2()._1()))) .when(op_args -> (Operator.any_of == op_args._1()), op_args -> new BasicDBObject(field, new BasicDBObject("$in", op_args._2()._1()))) .when(op_args -> (Operator.all_of == op_args._1()), op_args -> new BasicDBObject(field, new BasicDBObject("$all", op_args._2()._1()))) .when(op_args -> (Operator.equals == op_args._1()) && (null != op_args._2()._2()), op_args -> new BasicDBObject(field, new BasicDBObject("$ne", op_args._2()._2()))) .when(op_args -> (Operator.equals == op_args._1()), op_args -> new BasicDBObject(field, op_args._2()._1())) .when(op_args -> Operator.range_open_open == op_args._1(), op_args -> { QueryBuilder qb = QueryBuilder.start(field); if (null != op_args._2()._1()) qb = qb.greaterThan(op_args._2()._1()); if (null != op_args._2()._2()) qb = qb.lessThan(op_args._2()._2()); return (BasicDBObject) qb.get(); }).when(op_args -> Operator.range_open_closed == op_args._1(), op_args -> { QueryBuilder qb = QueryBuilder.start(field); if (null != op_args._2()._1()) qb = qb.greaterThan(op_args._2()._1()); if (null != op_args._2()._2()) qb = qb.lessThanEquals(op_args._2()._2()); return (BasicDBObject) qb.get(); }).when(op_args -> Operator.range_closed_closed == op_args._1(), op_args -> { QueryBuilder qb = QueryBuilder.start(field); if (null != op_args._2()._1()) qb = qb.greaterThanEquals(op_args._2()._1()); if (null != op_args._2()._2()) qb = qb.lessThanEquals(op_args._2()._2()); return (BasicDBObject) qb.get(); }).when(op_args -> Operator.range_closed_open == op_args._1(), op_args -> { QueryBuilder qb = QueryBuilder.start(field); if (null != op_args._2()._1()) qb = qb.greaterThanEquals(op_args._2()._1()); if (null != op_args._2()._2()) qb = qb.lessThan(op_args._2()._2()); return (BasicDBObject) qb.get(); }).otherwise(op_args -> new BasicDBObject()); } /** Top-level "is this query ANDing terms or ORing them" * @param op_in - the operator enum * @return - the mongodb operator */ protected static String getOperatorName(final Operator op_in) { return Patterns.match(op_in).<String>andReturn().when(op -> Operator.any_of == op, op -> "$or") .when(op -> Operator.all_of == op, op -> "$and").otherwise(op -> "$and"); } /** Creates a big $and/$or list of the list of "multi query components" * @param andVsOr - top level MongoDB operator * @param query_in - a multi query * @return the MongoDB query object (no meta - that is added above) */ @SuppressWarnings("unchecked") protected static <T> DBObject convertToMongoQuery_multi(final String andVsOr, final MultiQueryComponent<T> query_in) { return Patterns.match(query_in.getElements()).<DBObject>andReturn() .when(f -> f.isEmpty(), f -> new BasicDBObject()) .otherwise(f -> f.stream().collect(Collector.of(BasicDBList::new, (acc, entry) -> { Patterns.match(entry).andAct() .when(SingleQueryComponent.class, e -> acc.add(convertToMongoQuery_single(getOperatorName(e.getOp()), e))) .when(MultiQueryComponent.class, e -> acc.add(convertToMongoQuery_multi( getOperatorName(((MultiQueryComponent<?>) e).getOp()), (MultiQueryComponent<?>) e))); //(at various other points in the code, oraclej has complained about this though ecj is happy, so just added these casts for safety) }, (a, b) -> { a.addAll(b); return a; }, acc -> (DBObject) new BasicDBObject(andVsOr, acc), Characteristics.UNORDERED))); } /** Remove enums (convert to strings) before putting anything in a DBObject * @param in * @return */ protected static Tuple2<Object, Object> removeEnums(final Tuple2<Object, Object> in) { if (in._1() instanceof Enum && in._2() instanceof Enum) return Tuples._2T(in._1().toString(), in._2().toString()); else if (in._1() instanceof Enum) return Tuples._2T(in._1().toString(), in._2()); else if (in._2() instanceof Enum) return Tuples._2T(in._1(), in._2().toString()); else return in; } /** Creates a big $and/$or list of the list of fields in the single query component * @param andVsOr - top level MongoDB operator * @param query_in - a single query (ie set of fields) * @return the MongoDB query object (no meta - that is added above) */ protected static <T> DBObject convertToMongoQuery_single(final String andVsOr, final SingleQueryComponent<T> query_in) { final LinkedHashMultimap<String, Tuple2<Operator, Tuple2<Object, Object>>> fields = query_in.getAll(); // The actual query: return Patterns.match(fields).<DBObject>andReturn().when(f -> f.isEmpty(), f -> new BasicDBObject()) .otherwise(f -> f.asMap().entrySet().stream() .<Tuple2<String, Tuple2<Operator, Tuple2<Object, Object>>>>flatMap( entry -> entry.getValue().stream() .map(val -> Tuples._2T(entry.getKey(), Tuples._2T(val._1(), removeEnums(val._2()))))) .collect(Collector.of(BasicDBObject::new, (acc, entry) -> { Patterns.match(acc.get(andVsOr)).andAct().when(l -> (null == l), l -> { BasicDBList dbl = new BasicDBList(); dbl.add(operatorToMongoKey(entry._1(), entry._2())); acc.put(andVsOr, dbl); }).when(BasicDBList.class, l -> l.add(operatorToMongoKey(entry._1(), entry._2()))) .otherwise(() -> { }); }, (a, b) -> { a.putAll(b.toMap()); return a; }, Characteristics.UNORDERED))); } //////////////////////////////////////////////////////////////////////////////////////// // CREATE UPDATE /** Create a DB object from a bean template * @param bean_template * @return * @throws IOException * @throws JsonMappingException * @throws JsonGenerationException */ public static DBObject convertBeanTemplate(BeanTemplate<Object> bean_template, ObjectMapper object_mapper) { try { final BsonObjectGenerator generator = new BsonObjectGenerator(); object_mapper.writeValue(generator, bean_template.get()); return generator.getDBObject(); } catch (Exception e) { throw new RuntimeException(e); } } /** Create a DB object from a JsonNode * @param bean_template * @return * @throws IOException * @throws JsonMappingException * @throws JsonGenerationException */ public static DBObject convertJsonBean(JsonNode json, ObjectMapper object_mapper) { try { final BsonObjectGenerator generator = new BsonObjectGenerator(); object_mapper.writeTree(generator, json); return generator.getDBObject(); } catch (Exception e) { throw new RuntimeException(e); } } /** Create a MongoDB update object * @param update - the generic specification * @param add increments numbers or adds to sets/lists * @param remove decrements numbers of removes from sets/lists * @return the mongodb object * @throws IOException * @throws JsonMappingException * @throws JsonGenerationException */ @SuppressWarnings("unchecked") public static <O> DBObject createUpdateObject(final UpdateComponent<O> update) { final ObjectMapper object_mapper = MongoJackModule .configure(BeanTemplateUtils.configureMapper(Optional.empty())); return update.getAll().entries().stream() .map(kv -> Patterns .match(kv.getValue()._2()).<Map.Entry<String, Tuple2<UpdateOperator, Object>>>andReturn() // Special case, handle bean template .when(e -> null == e, __ -> kv) .when(e -> e instanceof Enum, e -> Maps.immutableEntry(kv.getKey(), Tuples._2T(kv.getValue()._1(), e.toString()))) .when(JsonNode.class, j -> Maps.immutableEntry(kv.getKey(), Tuples._2T(kv.getValue()._1(), convertJsonBean(j, object_mapper)))) .when(BeanTemplate.class, e -> Maps.immutableEntry(kv.getKey(), Tuples._2T(kv.getValue()._1(), convertBeanTemplate(e, object_mapper)))) // Special case, handle list of bean templates .when(Collection.class, l -> !l.isEmpty() && (l.iterator().next() instanceof JsonNode), l -> Maps.immutableEntry(kv.getKey(), Tuples._2T(kv.getValue()._1(), l.stream().map(j -> convertJsonBean((JsonNode) j, object_mapper)) .collect(Collectors.toList())))) .when(Collection.class, l -> !l.isEmpty() && (l.iterator().next() instanceof BeanTemplate), l -> Maps.immutableEntry(kv.getKey(), Tuples._2T(kv.getValue()._1(), l.stream() .map(e -> convertBeanTemplate((BeanTemplate<Object>) e, object_mapper)) .collect(Collectors.toList())))) .otherwise(() -> kv)) .collect(Collector.of(BasicDBObject::new, (acc, kv) -> { Patterns.match(kv.getValue()._2()).andAct() // Delete operator, bunch of things have to happen for safety .when(o -> ((UpdateOperator.unset == kv.getValue()._1()) && kv.getKey().isEmpty() && (null == kv.getValue()._2())), o -> acc.put("$unset", null)) //Increment .when(Number.class, n -> (UpdateOperator.increment == kv.getValue()._1()), n -> nestedPut(acc, "$inc", kv.getKey(), n)) // Set .when(o -> (UpdateOperator.set == kv.getValue()._1()), o -> nestedPut(acc, "$set", kv.getKey(), o)) // Unset .when(o -> (UpdateOperator.unset == kv.getValue()._1()), o -> nestedPut(acc, "$unset", kv.getKey(), 1)) // Add items/item to list .when(Collection.class, c -> (UpdateOperator.add == kv.getValue()._1()), c -> nestedPut(acc, "$push", kv.getKey(), new BasicDBObject("$each", c))) .when(o -> (UpdateOperator.add == kv.getValue()._1()), o -> nestedPut(acc, "$push", kv.getKey(), o)) // Add item/items to set .when(Collection.class, c -> (UpdateOperator.add_deduplicate == kv.getValue()._1()), c -> nestedPut(acc, "$addToSet", kv.getKey(), new BasicDBObject("$each", c))) .when(o -> (UpdateOperator.add_deduplicate == kv.getValue()._1()), o -> nestedPut(acc, "$addToSet", kv.getKey(), o)) // Remove items from list by query .when(QueryComponent.class, q -> (UpdateOperator.remove == kv.getValue()._1()), q -> nestedPut(acc, "$pull", kv.getKey(), convertToMongoQuery(q)._1())) // Remove items/item from list .when(Collection.class, c -> (UpdateOperator.remove == kv.getValue()._1()), c -> nestedPut(acc, "$pullAll", kv.getKey(), c)) .when(o -> (UpdateOperator.remove == kv.getValue()._1()), o -> nestedPut(acc, "$pullAll", kv.getKey(), Arrays.asList(o))) .otherwise(() -> { }); // (do nothing) }, (a, b) -> { a.putAll(b.toMap()); return a; }, Characteristics.UNORDERED)); } /** Inserts an object into field1.field2, creating objects along the way * @param mutable the mutable object into which the the nested field is inserted * @param parent the top level fieldname * @param nested the nested fieldname * @param to_insert the object to insert */ protected static void nestedPut(final BasicDBObject mutable, final String parent, final String nested, final Object to_insert) { final DBObject dbo = (DBObject) mutable.get(parent); if (null != dbo) { dbo.put(nested, to_insert); } else { BasicDBObject new_dbo = new BasicDBObject(); new_dbo.put(nested, to_insert); mutable.put(parent, new_dbo); } } }