/*
* Copyright (c) 2011. The Apache Software Foundation
*
* 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.yaoql.impl;
import org.apache.expreval.expr.ExpressionTree;
import org.apache.expreval.expr.literal.BooleanLiteral;
import org.apache.hadoop.hbase.hbql.client.HBqlException;
import org.apache.hadoop.hbase.hbql.mapping.MappingContext;
import org.apache.hadoop.hbase.hbql.parser.ParserUtil;
import org.apache.hadoop.hbase.hbql.util.Lists;
import org.apache.yaoql.client.ObjectQuery;
import org.apache.yaoql.client.ObjectQueryListener;
import org.apache.yaoql.client.ObjectResultSet;
import java.util.Collection;
import java.util.List;
public class ObjectQueryImpl<T> extends ParameterBinding implements ObjectQuery<T> {
private final String query;
private List<ObjectQueryListener<T>> queryListeners = null;
public ObjectQueryImpl(final String query) {
this.query = query;
}
public void addListener(final ObjectQueryListener<T> listener) {
if (this.getQueryListeners() == null)
this.queryListeners = Lists.newArrayList();
this.getQueryListeners().add(listener);
}
private List<ObjectQueryListener<T>> getQueryListeners() {
return this.queryListeners;
}
public void clearListeners() {
if (this.getQueryListeners() != null)
this.getQueryListeners().clear();
}
private void callOnQueryInit() {
if (this.getQueryListeners() != null) {
for (final ObjectQueryListener<T> listener : this.getQueryListeners())
listener.onQueryStart();
}
}
public T callOnEachObject(T val) {
if (this.getQueryListeners() != null) {
for (final ObjectQueryListener<T> listener : this.getQueryListeners())
listener.onEachObject(val);
}
return val;
}
public void callOnQueryComplete() {
if (this.getQueryListeners() != null) {
for (final ObjectQueryListener<T> listener : this.getQueryListeners())
listener.onQueryComplete();
}
}
public String getQuery() {
return this.query;
}
public ExpressionTree getExpressionTree(final Collection<T> objects) throws HBqlException {
final ExpressionTree expressionTree;
if (objects == null || objects.size() == 0) {
expressionTree = ExpressionTree.newExpressionTree(null, new BooleanLiteral(true));
expressionTree.setMappingContext(null);
expressionTree.setAllowColumns(false);
}
else {
// Grab the first object to derive the mapping
final Object obj = objects.iterator().next();
final ReflectionMapping mapping = ReflectionMapping.getReflectionMapping(obj);
final MappingContext mappingContext = new MappingContext(mapping);
expressionTree = ParserUtil.parseWhereExpression(this.getQuery(), mappingContext);
this.applyParameters(expressionTree);
}
return expressionTree;
}
public ObjectResultSet<T> getResults(final Collection<T> objs) throws HBqlException {
this.callOnQueryInit();
return new ObjectResultSet<T>(this, objs);
}
public List<T> getResultList(final Collection<T> objs) throws HBqlException {
final List<T> retval = Lists.newArrayList();
final ObjectResultSet<T> results = this.getResults(objs);
for (final T val : results)
retval.add(val);
return retval;
}
}