| /******************************************************************************* |
| * Copyright (c) 2007 Oracle Corporation. |
| * 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: |
| * Oracle - initial API and implementation |
| * |
| ********************************************************************************/ |
| package org.eclipse.jst.jsf.common.metadata.internal.provisional.query; |
| |
| import java.util.Iterator; |
| import java.util.Stack; |
| |
| import org.eclipse.jst.jsf.common.metadata.internal.provisional.Entity; |
| import org.eclipse.jst.jsf.common.metadata.internal.provisional.EntityGroup; |
| import org.eclipse.jst.jsf.common.metadata.internal.provisional.Trait; |
| |
| |
| /** |
| * A simple metadata query visitor implementing {@link IEntityQueryVisitor} and {@link ITraitQueryVisitor}. |
| * - simple find entity and traits by id only |
| * - Does not allow for wild card searchs |
| */ |
| public class SimpleMetaDataQueryVisitorImpl implements IEntityQueryVisitor, ITraitQueryVisitor { |
| |
| private String traitQuery; |
| private SearchControl control; |
| private boolean _stop; |
| |
| private EntityQueryComparator entityComparator; |
| private SimpleResultSet/*<Entity>*/ entityResultSet; |
| private SimpleResultSet/*<Trait>*/ traitResultSet; |
| |
| /** |
| * Constructor that also creates a default SearchControl |
| */ |
| public SimpleMetaDataQueryVisitorImpl() { |
| super(); |
| control = new SearchControl(); |
| } |
| |
| /** |
| * Constructor |
| * @param control |
| */ |
| public SimpleMetaDataQueryVisitorImpl(SearchControl control) { |
| super(); |
| this.control = control; |
| } |
| |
| /* (non-Javadoc) |
| * @see org.eclipse.jst.jsf.common.metadata.internal.provisional.query.ITraitQueryVisitor#findTraits(org.eclipse.jst.jsf.common.metadata.internal.provisional.Entity, java.lang.String) |
| */ |
| public IResultSet/*<Trait>*/ findTraits(final Entity entity, final String traitQuery){ |
| |
| resetQuery(); |
| if (entity != null){ |
| this.traitQuery = traitQuery; |
| for (Iterator/*<Trait>*/ it=entity.getTraits().iterator();it.hasNext();){ |
| Trait t = (Trait)it.next(); |
| t.accept(this); |
| if (stopVisiting()) |
| break; |
| } |
| } |
| return getTraitResultSet(); |
| } |
| |
| /* (non-Javadoc) |
| * @see org.eclipse.jst.jsf.common.metadata.internal.provisional.query.ITraitVisitor#visit(org.eclipse.jst.jsf.common.metadata.internal.provisional.Trait) |
| */ |
| public void visit(Trait trait) { |
| if (trait.equals(traitQuery)) |
| getTraitResultSet().addItem(trait); |
| |
| checkShouldStopVisitingTraits(); |
| } |
| |
| |
| /* (non-Javadoc) |
| * @see org.eclipse.jst.jsf.common.metadata.internal.provisional.query.IEntityQueryVisitor#findEntities(org.eclipse.jst.jsf.common.metadata.internal.provisional.Entity, java.lang.String) |
| */ |
| public IResultSet/*<Entity>*/ findEntities(Entity initialEntityContext, |
| String entityKey) { |
| |
| resetQuery(); |
| |
| if (initialEntityContext != null){ |
| entityComparator = new EntityQueryComparator(entityKey); |
| initialEntityContext.accept(this); |
| } |
| |
| return getEntityResultSet(); |
| } |
| |
| private void resetQuery() { |
| _stop = false; |
| } |
| |
| /** |
| * @return @return lazy init of a SimpleResultSet of Entities |
| */ |
| private SimpleResultSet/*<Entity>*/ getEntityResultSet(){ |
| if (entityResultSet == null){ |
| entityResultSet = new SimpleResultSet/*<Entity>*/(); |
| } |
| return entityResultSet; |
| } |
| |
| /** |
| * @return lazy init of a SimpleResultSet of Traits |
| */ |
| private SimpleResultSet/*<Trait>*/ getTraitResultSet(){ |
| if (traitResultSet == null){ |
| traitResultSet = new SimpleResultSet/*<Trait>*/(); |
| } |
| return traitResultSet; |
| } |
| |
| /* (non-Javadoc) |
| * @see org.eclipse.jst.jsf.common.metadata.internal.provisional.query.IEntityVisitor#visit(org.eclipse.jst.jsf.common.metadata.internal.provisional.Entity) |
| */ |
| public void visit(Entity key) { |
| switch (entityComparator.compareTo(key)){ |
| case 0: |
| getEntityResultSet().addItem(key); |
| break; |
| default: |
| break; |
| |
| } |
| checkShouldStopVisitingEntities(); |
| } |
| /* (non-Javadoc) |
| * @see org.eclipse.jst.jsf.common.metadata.internal.provisional.query.IEntityVisitor#visitCompleted() |
| */ |
| public void visitCompleted() { |
| entityComparator.popContext(); |
| } |
| |
| /* (non-Javadoc) |
| * @see org.eclipse.jst.jsf.common.metadata.internal.provisional.query.IMetaDataVisitor#stopVisiting() |
| */ |
| public boolean stopVisiting() { |
| return _stop; |
| } |
| |
| private void checkShouldStopVisitingEntities(){ |
| //implement how to set stop to signal to the entity accept() to skip visiting |
| if (control.getCountLimit()== getEntityResultSet().size() && control.getCountLimit() != SearchControl.COUNT_LIMIT_NONE ) |
| _stop = true; |
| } |
| |
| private void checkShouldStopVisitingTraits(){ |
| //this simple visitor will only find a single trait as it checks for exact match only currently |
| if (getTraitResultSet().size() > 0 ) |
| _stop = true; |
| } |
| |
| |
| /** |
| * Simple comparator that compares that an entity's id for with another |
| */ |
| private class EntityQueryComparator implements Comparable/*<Entity>*/{ |
| |
| private String entityKey; |
| private EntityStack stack; |
| |
| public EntityQueryComparator(String entityKey){ |
| this.entityKey = entityKey; |
| stack = new EntityStack(); |
| } |
| |
| public int compareTo(Object entity) { |
| stack.push(entity); |
| return entityKey.compareTo(getRelativeId()); |
| } |
| |
| public void popContext(){ |
| stack.pop(); |
| } |
| |
| private String getRelativeId(){ |
| int size = stack.size(); |
| int i = 1; |
| StringBuffer buf = new StringBuffer(); |
| while(i < size){ |
| Entity e = (Entity)stack.elementAt(i); |
| if (!(e instanceof EntityGroup)){ |
| if (buf.length()>0) |
| buf.append("/"); |
| buf.append(e.getId()); |
| } |
| i++; |
| } |
| return buf.toString(); |
| } |
| } |
| |
| /** |
| * Stack used for determining relative key of an entity from the initial context. |
| */ |
| private class EntityStack extends Stack/*<Entity>*/ { |
| public EntityStack(){ |
| super(); |
| } |
| } |
| |
| } |