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 * * 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.streams.neo4j; import org.apache.streams.graph.QueryGraphHelper; import org.apache.streams.jackson.StreamsJacksonMapper; import org.apache.streams.pojo.json.Activity; import org.apache.streams.pojo.json.ActivityObject; import org.apache.streams.util.PropertyUtil; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.node.ObjectNode; import org.apache.commons.lang3.StringEscapeUtils; import org.javatuples.Pair; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.stringtemplate.v4.ST; import java.io.Serializable; import java.util.ArrayList; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Objects; /** * Supporting class for interacting with neo4j via rest API */ public class CypherQueryGraphHelper implements QueryGraphHelper, Serializable { private static final ObjectMapper MAPPER = StreamsJacksonMapper.getInstance(); private static final Logger LOGGER = LoggerFactory.getLogger(CypherQueryGraphHelper.class); public static final String getVertexLongIdStatementTemplate = "MATCH (v) WHERE ID(v) = <id> RETURN v"; public static final String getVertexStringIdStatementTemplate = "MATCH (v {id: '<id>'} ) RETURN v"; public static final String getVerticesLabelIdStatementTemplate = "MATCH (v:<type>) RETURN v"; public final static String createVertexStatementTemplate = "MATCH (x {id: '<id>'}) " + "CREATE UNIQUE (v:`<type>` { props }) " + "ON CREATE SET v <labels> " + "RETURN v"; public final static String mergeVertexStatementTemplate = "MERGE (v:`<type>` {id: '<id>'}) " + "ON CREATE SET v <labels>, v = { props }, v.`@timestamp` = timestamp() " + "ON MATCH SET v <labels>, v = { props }, v.`@timestamp` = timestamp() " + "RETURN v"; public final static String createEdgeStatementTemplate = "MATCH (s:`<s_type>` {id: '<s_id>'}),(d:`<d_type>` {id: '<d_id>'}) " + "CREATE UNIQUE (s)-[r:`<r_type>` <r_props>]->(d) " + "RETURN r"; public Pair<String, Map<String, Object>> getVertexRequest(String streamsId) { ST getVertex = new ST(getVertexStringIdStatementTemplate); getVertex.add("id", streamsId); Pair<String, Map<String, Object>> queryPlusParameters = new Pair(getVertex.render(), null); LOGGER.debug("getVertexRequest", queryPlusParameters.toString()); return queryPlusParameters; } /** * getVertexRequest. * @param vertexId numericId * @return pair (streamsId, parameterMap) */ public Pair<String, Map<String, Object>> getVertexRequest(Long vertexId) { ST getVertex = new ST(getVertexLongIdStatementTemplate); getVertex.add("id", vertexId); Pair<String, Map<String, Object>> queryPlusParameters = new Pair(getVertex.render(), null); LOGGER.debug("getVertexRequest", queryPlusParameters.toString()); return queryPlusParameters; } /** * createVertexRequest. * @param activityObject activityObject * @return pair (query, parameterMap) */ public Pair<String, Map<String, Object>> createVertexRequest(ActivityObject activityObject) { Objects.requireNonNull(activityObject.getObjectType()); List<String> labels = getLabels(activityObject); ST createVertex = new ST(createVertexStatementTemplate); createVertex.add("id", activityObject.getId()); createVertex.add("type", activityObject.getObjectType()); if (labels.size() > 0) { createVertex.add("labels", String.join(" ", labels)); } String query = createVertex.render(); ObjectNode object = MAPPER.convertValue(activityObject, ObjectNode.class); Map<String, Object> props = PropertyUtil.flattenToMap(object, '.'); Pair<String, Map<String, Object>> queryPlusParameters = new Pair(createVertex.render(), props); LOGGER.debug("createVertexRequest: ({},{})", query, props); return queryPlusParameters; } /** * getVerticesRequest gets all vertices with a label. * @param labelId labelId * @return pair (query, parameterMap) */ public Pair<String, Map<String, Object>> getVerticesRequest(String labelId) { ST getVertex = new ST(getVerticesLabelIdStatementTemplate); getVertex.add("type", labelId); Pair<String, Map<String, Object>> queryPlusParameters = new Pair(getVertex.render(), null); LOGGER.debug("getVertexRequest", queryPlusParameters.toString()); return queryPlusParameters; } /** * mergeVertexRequest. * @param activityObject activityObject * @return pair (query, parameterMap) */ public Pair<String, Map<String, Object>> mergeVertexRequest(ActivityObject activityObject) { Objects.requireNonNull(activityObject.getObjectType()); Pair queryPlusParameters = new Pair(null, new HashMap<>()); List<String> labels = getLabels(activityObject); ST mergeVertex = new ST(mergeVertexStatementTemplate); mergeVertex.add("id", activityObject.getId()); mergeVertex.add("type", activityObject.getObjectType()); if (labels.size() > 0) { mergeVertex.add("labels", String.join(" ", labels)); } String query = mergeVertex.render(); ObjectNode object = MAPPER.convertValue(activityObject, ObjectNode.class); Map<String, Object> props = PropertyUtil.flattenToMap(object, '.'); LOGGER.debug("mergeVertexRequest: ({},{})", query, props); queryPlusParameters = queryPlusParameters.setAt0(query); queryPlusParameters = queryPlusParameters.setAt1(props); return queryPlusParameters; } /** * createActorObjectEdge. * @param activity activity * @return pair (query, parameterMap) */ public Pair<String, Map<String, Object>> createActorObjectEdge(Activity activity) { Pair queryPlusParameters = new Pair(null, new HashMap<>()); ObjectNode object = MAPPER.convertValue(activity, ObjectNode.class); Map<String, Object> props = PropertyUtil.flattenToMap(object, '.'); ST mergeEdge = new ST(createEdgeStatementTemplate); mergeEdge.add("s_id", activity.getActor().getId()); mergeEdge.add("s_type", activity.getActor().getObjectType()); mergeEdge.add("d_id", activity.getObject().getId()); mergeEdge.add("d_type", activity.getObject().getObjectType()); mergeEdge.add("r_id", activity.getId()); mergeEdge.add("r_type", activity.getVerb()); mergeEdge.add("r_props", getActorObjectEdgePropertyCreater(props)); String statement = mergeEdge.render(); queryPlusParameters = queryPlusParameters.setAt0(statement); queryPlusParameters = queryPlusParameters.setAt1(props); LOGGER.debug("createActorObjectEdge: ({},{})", statement, props); return queryPlusParameters; } /** * createActorTargetEdge. * @param activity activity * @return pair (query, parameterMap) */ public Pair<String, Map<String, Object>> createActorTargetEdge(Activity activity) { Pair queryPlusParameters = new Pair(null, new HashMap<>()); ObjectNode object = MAPPER.convertValue(activity, ObjectNode.class); Map<String, Object> props = PropertyUtil.flattenToMap(object, '.'); ST mergeEdge = new ST(createEdgeStatementTemplate); mergeEdge.add("s_id", activity.getActor().getId()); mergeEdge.add("s_type", activity.getActor().getObjectType()); mergeEdge.add("d_id", activity.getTarget().getId()); mergeEdge.add("d_type", activity.getTarget().getObjectType()); mergeEdge.add("r_id", activity.getId()); mergeEdge.add("r_type", activity.getVerb()); mergeEdge.add("r_props", getActorTargetEdgePropertyCreater(props)); String statement = mergeEdge.render(); queryPlusParameters = queryPlusParameters.setAt0(statement); queryPlusParameters = queryPlusParameters.setAt1(props); LOGGER.debug("createActorObjectEdge: ({},{})", statement, props); return queryPlusParameters; } /** * getPropertyValueSetter. * @param map paramMap * @return PropertyValueSetter string */ public static String getPropertyValueSetter(Map<String, Object> map, String symbol) { StringBuilder builder = new StringBuilder(); for (Map.Entry<String, Object> entry : map.entrySet()) { if (entry.getValue() instanceof String) { String propVal = (String) (entry.getValue()); builder.append("," + symbol + ".`" + entry.getKey() + "` = '" + StringEscapeUtils.escapeJava(propVal) + "'"); } } return builder.toString(); } /** * getPropertyParamSetter. * @param map paramMap * @return PropertyParamSetter string */ public static String getPropertyParamSetter(Map<String, Object> map, String symbol) { StringBuilder builder = new StringBuilder(); for (Map.Entry<String, Object> entry : map.entrySet()) { if (entry.getValue() instanceof String) { String propVal = (String) (entry.getValue()); builder.append("," + symbol + ".`" + entry.getKey() + "` = '" + StringEscapeUtils.escapeJava(propVal) + "'"); } } return builder.toString(); } /** * getPropertyCreater. * @param map paramMap * @return PropertyCreater string */ public static String getPropertyCreater(Map<String, Object> map) { StringBuilder builder = new StringBuilder(); builder.append("{ "); List<String> parts = new ArrayList<>(); for (Map.Entry<String, Object> entry : map.entrySet()) { if (entry.getValue() instanceof String) { String propVal = (String) (entry.getValue()); parts.add("`" + entry.getKey() + "`:'" + StringEscapeUtils.escapeJava(propVal) + "'"); } } builder.append(String.join(" ", parts)); builder.append(" }"); return builder.toString(); } private String getActorObjectEdgePropertyCreater(Map<String, Object> map) { StringBuilder builder = new StringBuilder(); builder.append("{ "); List<String> parts = new ArrayList<>(); for (Map.Entry<String, Object> entry : map.entrySet()) { if (entry.getValue() instanceof String) { String propVal = (String) (entry.getValue()); if (!entry.getKey().contains(".")) { parts.add("`" + entry.getKey() + "`: '" + StringEscapeUtils.escapeJava(propVal) + "'"); } } } builder.append(String.join(", ", parts)); builder.append(" }"); return builder.toString(); } private String getActorTargetEdgePropertyCreater(Map<String, Object> map) { StringBuilder builder = new StringBuilder(); builder.append("{ "); List<String> parts = new ArrayList<>(); for (Map.Entry<String, Object> entry : map.entrySet()) { if (entry.getValue() instanceof String) { String propVal = (String) (entry.getValue()); if (!entry.getKey().contains(".")) { parts.add("`" + entry.getKey() + "`: '" + StringEscapeUtils.escapeJava(propVal) + "'"); } else if (entry.getKey().startsWith("object.") && !entry.getKey().contains(".id")) { parts.add("`" + entry.getKey().substring("object.".length()) + "`: '" + StringEscapeUtils.escapeJava(propVal) + "'"); } } } builder.append(String.join(", ", parts)); builder.append(" }"); return builder.toString(); } /** * getLabels. * @param activityObject activityObject * @return PropertyCreater string */ public static List<String> getLabels(ActivityObject activityObject) { List<String> labels = Collections.singletonList(":streams"); if (activityObject.getAdditionalProperties().containsKey("labels")) { List<String> extraLabels = (List<String>) activityObject.getAdditionalProperties().get("labels"); for (String extraLabel : extraLabels) { labels.add(":" + extraLabel); } } return labels; } }