| /* |
| * 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.openjpa.kernel.exps; |
| |
| import java.io.Serializable; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.LinkedHashMap; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Stack; |
| |
| import org.apache.openjpa.kernel.QueryOperations; |
| import org.apache.openjpa.kernel.ResultShape; |
| import org.apache.openjpa.kernel.StoreQuery; |
| import org.apache.openjpa.lib.util.OrderedMap; |
| import org.apache.openjpa.meta.ClassMetaData; |
| import org.apache.openjpa.meta.FieldMetaData; |
| |
| /** |
| * Struct to hold the state of a parsed expression query. |
| * |
| * @author Abe White |
| * @since 0.3.2 |
| */ |
| public class QueryExpressions implements Serializable { |
| private static final long serialVersionUID = 1L; |
| public static final int DISTINCT_AUTO = 2 << 0; |
| public static final int DISTINCT_TRUE = 2 << 1; |
| public static final int DISTINCT_FALSE = 2 << 2; |
| public static final Value[] EMPTY_VALUES = new Value[0]; |
| |
| /** |
| * Map of {@link FieldMetaData},{@link Value} for update statements. |
| */ |
| public Map<Path, Value> updates = Collections.emptyMap(); |
| public int distinct = DISTINCT_AUTO; |
| public String alias = null; |
| public Value[] projections = EMPTY_VALUES; |
| public String[] projectionClauses = StoreQuery.EMPTY_STRINGS; |
| public String[] projectionAliases = StoreQuery.EMPTY_STRINGS; |
| public Class<?> resultClass = null; |
| public Expression filter = null; |
| public Value[] grouping = EMPTY_VALUES; |
| public String[] groupingClauses = StoreQuery.EMPTY_STRINGS; |
| public Expression having = null; |
| public Value[] ordering = EMPTY_VALUES; |
| public boolean[] ascending = StoreQuery.EMPTY_BOOLEANS; |
| public String[] orderingClauses = StoreQuery.EMPTY_STRINGS; |
| public String[] orderingAliases = StoreQuery.EMPTY_STRINGS; |
| public OrderedMap<Object,Class<?>> parameterTypes = StoreQuery.EMPTY_ORDERED_PARAMS; |
| public int operation = QueryOperations.OP_SELECT; |
| public ClassMetaData[] accessPath = StoreQuery.EMPTY_METAS; |
| public String[] fetchPaths = StoreQuery.EMPTY_STRINGS; |
| public String[] fetchInnerPaths = StoreQuery.EMPTY_STRINGS; |
| public Value[] range = EMPTY_VALUES; |
| private Boolean _aggregate = null; |
| private Stack<Context> _contexts = null; |
| public Object state; |
| public ResultShape<?> shape; |
| public boolean hasInExpression; |
| |
| /** |
| * Set reference to the JPQL query contexts. |
| */ |
| public void setContexts(Stack<Context> contexts) { |
| _contexts = contexts; |
| } |
| |
| /** |
| * Returns the current JPQL query context. |
| */ |
| public Context ctx() { |
| return _contexts.peek(); |
| } |
| |
| /** |
| * Whether this is an aggregate results. |
| */ |
| public boolean isAggregate() { |
| if (projections.length == 0) |
| return false; |
| if (_aggregate == null) |
| _aggregate = (AggregateExpressionVisitor.isAggregate(projections)) |
| ? Boolean.TRUE : Boolean.FALSE; |
| return _aggregate; |
| } |
| |
| public boolean isDistinct() { |
| return distinct != DISTINCT_FALSE; |
| } |
| |
| /** |
| * Gets the fields that are bound to parameters. |
| * |
| * @return empty if the query has no filtering condition or no parameters. |
| */ |
| public List<FieldMetaData> getParameterizedFields() { |
| return ParameterExpressionVisitor.collectParameterizedFields(filter); |
| } |
| |
| /** |
| * Add an update. |
| */ |
| public void putUpdate(Path path, Value val) { |
| if (updates == Collections.EMPTY_MAP) |
| updates = new LinkedHashMap<>(); |
| updates.put(path, val); |
| } |
| |
| /** |
| * Visitor to determine whether our projections are aggregates. |
| */ |
| private static class AggregateExpressionVisitor |
| extends AbstractExpressionVisitor { |
| |
| private Value _sub = null; |
| private boolean _agg = false; |
| |
| /** |
| * Return whether the given values include projections. |
| */ |
| public static boolean isAggregate(Value[] vals) { |
| if (vals.length == 0) |
| return false; |
| AggregateExpressionVisitor v = new AggregateExpressionVisitor(); |
| for (int i = 0; i < vals.length && !v._agg; i++) |
| vals[i].acceptVisit(v); |
| return v._agg; |
| } |
| |
| @Override |
| public void enter(Value val) { |
| if (_agg) |
| return; |
| if (_sub == null) { |
| if (val.isAggregate()) |
| _agg = true; |
| } else if (val instanceof Subquery) |
| _sub = val; |
| } |
| |
| @Override |
| public void exit(Value val) { |
| if (val == _sub) |
| _sub = null; |
| } |
| } |
| |
| /** |
| * Visits the expression tree to find the parameter nodes. |
| * @author Pinaki Poddar |
| * |
| */ |
| private static class ParameterExpressionVisitor extends AbstractExpressionVisitor { |
| private FieldMetaData _parameterized; |
| private List<FieldMetaData> _collected = new ArrayList<>(); |
| /** |
| * Enters the current node. |
| */ |
| @Override |
| public void enter(Value val) { |
| if (val instanceof Parameter) { |
| if (_parameterized != null) { |
| _collected.add(_parameterized); |
| } |
| } else if (val instanceof Path) { |
| _parameterized = ((Path)val).last(); |
| } else { |
| _parameterized = null; |
| } |
| } |
| |
| public static List<FieldMetaData> collectParameterizedFields(Expression e) { |
| if (e == null) { |
| return Collections.emptyList(); |
| } |
| ParameterExpressionVisitor visitor = new ParameterExpressionVisitor(); |
| e.acceptVisit(visitor); |
| return visitor._collected; |
| } |
| |
| } |
| } |