org.modeshape.jcr.query.model.Query Maven / Gradle / Ivy
/*
* ModeShape (http://www.modeshape.org)
*
* Licensed 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.modeshape.jcr.query.model;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import org.modeshape.common.annotation.Immutable;
import org.modeshape.common.util.CheckArg;
import org.modeshape.common.util.HashCode;
import org.modeshape.common.util.ObjectUtil;
/**
*
*/
@Immutable
public class Query implements QueryCommand {
private static final long serialVersionUID = 1L;
public static final boolean IS_DISTINCT_DEFAULT = false;
private final List orderings;
private final Limit limits;
private final Source source;
private final Constraint constraint;
private final List columns;
private final boolean distinct;
private final int hc;
private transient javax.jcr.query.qom.Column[] columnArray;
private transient javax.jcr.query.qom.Ordering[] orderingArray;
/**
* Create a new query that uses the supplied source.
*
* @param source the source
* @throws IllegalArgumentException if the source is null
*/
public Query( Source source ) {
super();
CheckArg.isNotNull(source, "source");
this.orderings = Collections.emptyList();
this.limits = Limit.NONE;
this.source = source;
this.constraint = null;
this.columns = Collections.emptyList();
this.distinct = IS_DISTINCT_DEFAULT;
this.hc = HashCode.compute(this.source, this.constraint, this.columns, this.distinct);
}
/**
* Create a new query that uses the supplied source, constraint, orderings, columns and limits.
*
* @param source the source
* @param constraint the constraint (or composite constraint), or null or empty if there are no constraints
* @param orderings the specifications of how the results are to be ordered, or null if the order is to be implementation
* determined
* @param columns the columns to be included in the results, or null or empty if there are no explicit columns and the actual
* result columns are to be implementation determiend
* @param limit the limit for the results, or null if all of the results are to be included
* @param isDistinct true if duplicates are to be removed from the results
* @throws IllegalArgumentException if the source is null
*/
public Query( Source source,
Constraint constraint,
List orderings,
List columns,
Limit limit,
boolean isDistinct ) {
CheckArg.isNotNull(source, "source");
this.source = source;
this.constraint = constraint;
this.columns = columns != null ? columns : Collections.emptyList();
this.distinct = isDistinct;
this.orderings = orderings != null ? orderings : Collections.emptyList();
this.limits = limit != null ? limit : Limit.NONE;
this.hc = HashCode.compute(this.source, this.constraint, this.columns, this.distinct);
}
@Override
public Limit getLimits() {
return limits;
}
@Override
public List orderings() {
return orderings;
}
/**
* Get the source for the results.
*
* @return the query source; never null
*/
public Source source() {
return source;
}
/**
* Get the constraints, if there are any.
*
* @return the constraint; may be null
*/
public Constraint constraint() {
return constraint;
}
@Override
public List columns() {
return columns;
}
@Override
public javax.jcr.query.qom.Ordering[] getOrderings() {
if (orderingArray == null) {
// this is idempotent ...
orderingArray = orderings.toArray(new javax.jcr.query.qom.Ordering[orderings.size()]);
}
return orderingArray;
}
@Override
public javax.jcr.query.qom.Column[] getColumns() {
if (columnArray == null) {
// this is idempotent ...
columnArray = columns.toArray(new javax.jcr.query.qom.Column[columns.size()]);
}
return columnArray;
}
/**
* Determine whether this query is to return only distinct values.
*
* @return true if the query is to remove duplicate tuples, or false otherwise
*/
public boolean isDistinct() {
return distinct;
}
/**
* Create a copy of this query, but one in which there are no duplicate rows in the results.
*
* @return the copy of the query with no duplicate result rows; never null
*/
public Query distinct() {
return new Query(source, constraint, orderings(), columns, getLimits(), true);
}
/**
* Create a copy of this query, but one in which there may be duplicate rows in the results.
*
* @return the copy of the query with potentially duplicate result rows; never null
*/
public Query noDistinct() {
return new Query(source, constraint, orderings(), columns, getLimits(), false);
}
/**
* Create a copy of this query, but one that uses the supplied constraint.
*
* @param constraint the constraint that should be used; never null
* @return the copy of the query that uses the supplied constraint; never null
*/
public Query constrainedBy( Constraint constraint ) {
return new Query(source, constraint, orderings(), columns, getLimits(), distinct);
}
/**
* Create a copy of this query, but one whose results should be ordered by the supplied orderings.
*
* @param orderings the result ordering specification that should be used; never null
* @return the copy of the query that uses the supplied ordering; never null
*/
public Query orderedBy( List orderings ) {
return new Query(source, constraint, orderings, columns, getLimits(), distinct);
}
@Override
public Query withLimit( int rowLimit ) {
if (getLimits().getRowLimit() == rowLimit) return this; // nothing to change
return new Query(source, constraint, orderings(), columns, getLimits().withRowLimit(rowLimit), distinct);
}
@Override
public Query withOffset( int offset ) {
if (getLimits().getOffset() == offset) return this; // nothing to change
return new Query(source, constraint, orderings(), columns, getLimits().withOffset(offset), distinct);
}
/**
* Create a copy of this query, but that returns results with the supplied columns.
*
* @param columns the columns of the results; may not be null
* @return the copy of the query returning the supplied result columns; never null
*/
public Query returning( List columns ) {
return new Query(source, constraint, orderings(), columns, getLimits(), distinct);
}
/**
* Create a copy of this query, but that returns results that are ordered by the {@link #orderings() orderings} of this column
* as well as those supplied.
*
* @param orderings the additional orderings of the result rows; may no be null
* @return the copy of the query returning the supplied result columns; never null
*/
public Query adding( Ordering... orderings ) {
List newOrderings = null;
if (this.orderings() != null) {
newOrderings = new ArrayList(orderings());
for (Ordering ordering : orderings) {
newOrderings.add(ordering);
}
} else {
newOrderings = Arrays.asList(orderings);
}
return new Query(source, constraint, newOrderings, columns, getLimits(), distinct);
}
/**
* Create a copy of this query, but that returns results that include the columns specified by this query as well as the
* supplied columns.
*
* @param columns the additional columns that should be included in the the results; may not be null
* @return the copy of the query returning the supplied result columns; never null
*/
public Query adding( Column... columns ) {
List newColumns = null;
if (this.columns != null) {
newColumns = new ArrayList(this.columns);
for (Column column : columns) {
newColumns.add(column);
}
} else {
newColumns = Arrays.asList(columns);
}
return new Query(source, constraint, orderings(), newColumns, getLimits(), distinct);
}
@Override
public String toString() {
return Visitors.readable(this);
}
@Override
public int hashCode() {
return hc;
}
@Override
public boolean equals( Object obj ) {
if (obj == this) return true;
if (obj instanceof Query) {
Query that = (Query)obj;
if (this.hc != that.hc) return false;
if (this.distinct != that.distinct) return false;
if (!this.source.equals(that.source)) return false;
if (!ObjectUtil.isEqualWithNulls(this.getLimits(), that.getLimits())) return false;
if (!ObjectUtil.isEqualWithNulls(this.constraint, that.constraint)) return false;
if (!ObjectUtil.isEqualWithNulls(this.columns, that.columns)) return false;
if (!ObjectUtil.isEqualWithNulls(this.orderings(), that.orderings())) return false;
return true;
}
return false;
}
@Override
public void accept( Visitor visitor ) {
visitor.visit(this);
}
}
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