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.tinkerpop.gremlin.groovy.jsr223; import org.apache.commons.configuration.ConfigurationConverter; import org.apache.tinkerpop.gremlin.process.traversal.Bytecode; import org.apache.tinkerpop.gremlin.process.traversal.P; import org.apache.tinkerpop.gremlin.process.traversal.SackFunctions; import org.apache.tinkerpop.gremlin.process.traversal.Translator; import org.apache.tinkerpop.gremlin.process.traversal.Traversal; import org.apache.tinkerpop.gremlin.process.traversal.TraversalSource; import org.apache.tinkerpop.gremlin.process.traversal.TraversalStrategy; import org.apache.tinkerpop.gremlin.process.traversal.step.TraversalOptionParent; import org.apache.tinkerpop.gremlin.process.traversal.strategy.TraversalStrategyProxy; import org.apache.tinkerpop.gremlin.process.traversal.util.ConnectiveP; import org.apache.tinkerpop.gremlin.process.traversal.util.OrP; import org.apache.tinkerpop.gremlin.structure.Edge; import org.apache.tinkerpop.gremlin.structure.Element; import org.apache.tinkerpop.gremlin.structure.Vertex; import org.apache.tinkerpop.gremlin.structure.VertexProperty; import org.apache.tinkerpop.gremlin.structure.util.StringFactory; import org.apache.tinkerpop.gremlin.util.function.Lambda; import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Map; import java.util.Set; /** * @author Marko A. Rodriguez (http://markorodriguez.com) */ public final class GroovyTranslator implements Translator.ScriptTranslator { private final String traversalSource; private GroovyTranslator(final String traversalSource) { this.traversalSource = traversalSource; } public static final GroovyTranslator of(final String traversalSource) { return new GroovyTranslator(traversalSource); } /////// @Override public String translate(final Bytecode bytecode) { return this.internalTranslate(this.traversalSource, bytecode); } @Override public String getTargetLanguage() { return "gremlin-groovy"; } @Override public String toString() { return StringFactory.translatorString(this); } @Override public String getTraversalSource() { return this.traversalSource; } /////// private String internalTranslate(final String start, final Bytecode bytecode) { final StringBuilder traversalScript = new StringBuilder(start); for (final Bytecode.Instruction instruction : bytecode.getInstructions()) { final String methodName = instruction.getOperator(); if (0 == instruction.getArguments().length) traversalScript.append(".").append(methodName).append("()"); else { traversalScript.append("."); String temp = methodName + "("; for (final Object object : instruction.getArguments()) { temp = temp + convertToString(object) + ","; } traversalScript.append(temp.substring(0, temp.length() - 1)).append(")"); } } return traversalScript.toString(); } private String convertToString(final Object object) { if (object instanceof Bytecode.Binding) return ((Bytecode.Binding) object).variable(); else if (object instanceof Bytecode) return this.internalTranslate("__", (Bytecode) object); else if (object instanceof Traversal) return convertToString(((Traversal) object).asAdmin().getBytecode()); else if (object instanceof String) { return (((String) object).contains("\"") ? "\"\"\"" + object + "\"\"\"" : "\"" + object + "\"") .replace("$", "\\$"); } else if (object instanceof Set) { final Set<String> set = new HashSet<>(((Set) object).size()); for (final Object item : (Set) object) { set.add(convertToString(item)); } return set.toString() + " as Set"; } else if (object instanceof List) { final List<String> list = new ArrayList<>(((List) object).size()); for (final Object item : (List) object) { list.add(convertToString(item)); } return list.toString(); } else if (object instanceof Map) { final StringBuilder map = new StringBuilder("new LinkedHashMap(){{"); for (final Map.Entry<?, ?> entry : ((Map<?, ?>) object).entrySet()) { map.append("put(").append(convertToString(entry.getKey())).append(",") .append(convertToString(entry.getValue())).append(");"); } return map.append("}}").toString(); } else if (object instanceof Long) return object + "L"; else if (object instanceof Double) return object + "d"; else if (object instanceof Float) return object + "f"; else if (object instanceof Integer) return "(int) " + object; else if (object instanceof Class) return ((Class) object).getCanonicalName(); else if (object instanceof P) return convertPToString((P) object, new StringBuilder()).toString(); else if (object instanceof SackFunctions.Barrier) return "SackFunctions.Barrier." + object.toString(); else if (object instanceof VertexProperty.Cardinality) return "VertexProperty.Cardinality." + object.toString(); else if (object instanceof TraversalOptionParent.Pick) return "TraversalOptionParent.Pick." + object.toString(); else if (object instanceof Enum) return ((Enum) object).getDeclaringClass().getSimpleName() + "." + object.toString(); else if (object instanceof Element) { final String id = convertToString(((Element) object).id()); String temp = this.traversalSource.equals("__") ? "g" : this.traversalSource; if (object instanceof Vertex) temp = temp + ".V(" + id + ").next()"; else if (object instanceof Edge) temp = temp + ".E(" + id + ").next()"; else { final VertexProperty vertexProperty = (VertexProperty) object; temp = temp + ".V(" + convertToString(vertexProperty.element().id()) + ").properties(" + convertToString(vertexProperty.key()) + ").hasId(" + id + ").next()"; } return temp; } else if (object instanceof Lambda) { final String lambdaString = ((Lambda) object).getLambdaScript().trim(); return lambdaString.startsWith("{") ? lambdaString : "{" + lambdaString + "}"; } else if (object instanceof TraversalStrategyProxy) { final TraversalStrategyProxy proxy = (TraversalStrategyProxy) object; if (proxy.getConfiguration().isEmpty()) return proxy.getStrategyClass().getCanonicalName() + ".instance()"; else return proxy.getStrategyClass().getCanonicalName() + ".create(new org.apache.commons.configuration.MapConfiguration(" + convertToString(ConfigurationConverter.getMap(proxy.getConfiguration())) + "))"; } else if (object instanceof TraversalStrategy) { return convertToString(new TraversalStrategyProxy(((TraversalStrategy) object))); } else return null == object ? "null" : object.toString(); } private StringBuilder convertPToString(final P p, final StringBuilder current) { if (p instanceof ConnectiveP) { final List<P<?>> list = ((ConnectiveP) p).getPredicates(); for (int i = 0; i < list.size(); i++) { convertPToString(list.get(i), current); if (i < list.size() - 1) current.append(p instanceof OrP ? ".or(" : ".and("); } current.append(")"); } else current.append("P.").append(p.getBiPredicate().toString()).append("(") .append(convertToString(p.getValue())).append(")"); return current; } }