Java tutorial
/******************************************************************************* * Copyright (c) 2009 Cambridge Semantics Incorporated. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * Cambridge Semantics Incorporated *******************************************************************************/ package org.openanzo.glitter.query; import java.util.EnumSet; import java.util.List; import java.util.Map; import java.util.Map.Entry; import org.apache.commons.collections15.BidiMap; import org.apache.commons.collections15.bidimap.TreeBidiMap; import org.openanzo.glitter.Engine; import org.openanzo.glitter.dataset.QueryDataset; import org.openanzo.glitter.syntax.concrete.ParseException; import org.openanzo.rdf.URI; import org.openanzo.rdf.Variable; /** * A SubqueryController specializes {@link QueryController} to be used for capturing the details of a subquery. Subqueries are more limited versions of full * queries - they can only be initialized from existing queries and copy things like base URI, prefix map, and dataset information from their parent. * * @author lee <lee@cambridgesemantics.com> * */ public class SubqueryController extends QueryController { private QueryController parent; /** * @param parent */ public SubqueryController(QueryController parent) { this.parent = parent; } @Override public void setEngine(Engine engine) { if (engine == null || !engine.equals(getEngine())) throw new UnsupportedOperationException( "Subqueries cannot have a different engine from the parent query."); } @Override public Engine getEngine() { return this.parent.getEngine(); } @Override public QueryDataset getQueryDataset() { return parent.getQueryDataset(); } @Override public void setQueryDataset(QueryDataset queryDataset) { throw new UnsupportedOperationException("Subqueries cannot set the query Dataset."); } @Override public void setBaseUri(URI u) { throw new UnsupportedOperationException( "Subqueries cannot have a different base URI from the parent query."); } @Override public URI getBaseUri() { return this.parent.getBaseUri(); } @Override public void mapPrefix(String prefix, URI uri) { throw new UnsupportedOperationException( "Subqueries cannot have a different set of prefixes from the parent query."); } @Override public URI resolveQName(String prefix, String localPart) throws ParseException { return this.parent.resolveQName(prefix, localPart); } @Override public SolutionGenerator getSolutionGenerator() { return this.parent.getSolutionGenerator(); } @Override public void setSolutionGenerator(SolutionGenerator solutionGenerator) { throw new UnsupportedOperationException( "Subqueries cannot have a different solution generator from the parent query."); } @Override public void prettyPrint(StringBuilder buffer) { buffer.append("Query("); int limit = this.getLimit(); if (limit > -1) buffer.append("LIMIT(" + limit + "), "); int offset = this.getOffset(); if (offset > -1) buffer.append("OFFSET(" + offset + "), "); List<OrderingCondition> orderingConditions = this.getOrderingConditions(); if (orderingConditions.size() > 0) { buffer.append("OrderBy("); int i = 0; for (OrderingCondition condition : orderingConditions) { condition.getCondition().prettyPrint(buffer); if (++i < orderingConditions.size()) buffer.append(", "); } buffer.append("), "); } this.getQueryResultForm().prettyPrint(buffer); buffer.append(", GraphPattern("); queryPattern.prettyPrint(buffer); buffer.append(")"); buffer.append(")"); } /** * Pretty print query string * * @param printFlags * print flags * @param startIndentLevel * @return pretty print version of query */ @SuppressWarnings("all") public String prettyPrintQueryString(EnumSet<QueryStringPrintOptions> printFlags, int startIndentLevel) { StringBuilder s = new StringBuilder(); prettyPrintQueryStringPart(printFlags, startIndentLevel, s); return s.toString(); } /** * Pretty print query string * * @param printFlags * print flags * @param startIndentLevel * @return pretty print version of query */ @SuppressWarnings("all") public void prettyPrintQueryStringPart(EnumSet<QueryStringPrintOptions> printFlags, int startIndentLevel, StringBuilder s) { QueryResultForm queryResultForm = this.getQueryResultForm(); final BidiMap<String, String> prefix2uri = new TreeBidiMap<String, String>(); Map<String, String> uri2prefix = prefix2uri.inverseBidiMap(); for (Entry<String, URI> e : this.parent.prefixMap.entrySet()) prefix2uri.put(e.getKey(), e.getValue().toString()); this.resultForm.prettyPrintQueryPart(printFlags, startIndentLevel, uri2prefix, s); printSeparator(printFlags, startIndentLevel, s); s.append("WHERE {"); printSeparator(printFlags, startIndentLevel + 1, s); this.queryPattern.prettyPrintQueryPart(printFlags, startIndentLevel + 1, uri2prefix, s); printSeparator(printFlags, startIndentLevel, s); s.append("}"); if (queryResultForm instanceof Projection) { Projection projection = (Projection) queryResultForm; if (!projection.getGroupByVariables().isEmpty()) { printSeparator(printFlags, startIndentLevel, s); projection.prettyPrintGroupByQueryPart(printFlags, startIndentLevel, uri2prefix, s); } } if (this.ordering.size() > 0) { printSeparator(printFlags, 0, s); s.append("ORDER BY "); for (int i = 0; i < this.ordering.size(); i++) { OrderingCondition c = this.ordering.get(i); if (i != 0) s.append(' '); c.prettyPrintQueryPart(printFlags, startIndentLevel, uri2prefix, s); } printSeparator(printFlags, startIndentLevel, s); } if (this.limit > -1) { printSeparator(printFlags, startIndentLevel, s); s.append("LIMIT "); s.append(this.limit); } if (this.offset > -1) { printSeparator(printFlags, startIndentLevel, s); s.append("OFFSET "); s.append(this.offset); } } @Override public String getQueryString(boolean includeFromClauses) { QueryResultForm queryResultForm = this.getQueryResultForm(); StringBuilder s = new StringBuilder(this.resultForm.toString()); s.append(" WHERE { "); s.append(this.queryPattern); s.append(" }"); if (this.ordering.size() > 0) { s.append(" ORDER BY"); for (OrderingCondition c : this.ordering) s.append(" " + c.getCondition()); } if (queryResultForm instanceof Projection) { Projection projection = (Projection) queryResultForm; List<Variable> vars = projection.getGroupByVariables(); if (vars != null && !vars.isEmpty()) { s.append(" GROUP BY"); for (Variable v : vars) s.append(" " + v); } } if (this.limit > -1) s.append(" LIMIT " + this.limit); if (this.offset > -1) s.append(" OFFSET " + this.offset); return s.toString(); } }