/*
* 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.jdbc.kernel;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.apache.openjpa.jdbc.meta.ClassMapping;
import org.apache.openjpa.jdbc.meta.Joinable;
import org.apache.openjpa.jdbc.schema.Column;
import org.apache.openjpa.jdbc.sql.DBDictionary;
import org.apache.openjpa.jdbc.sql.LogicalUnion;
import org.apache.openjpa.jdbc.sql.Result;
import org.apache.openjpa.jdbc.sql.SQLBuffer;
import org.apache.openjpa.jdbc.sql.SelectExecutor;
import org.apache.openjpa.jdbc.sql.SelectImpl;
import org.apache.openjpa.jdbc.sql.Union;
import org.apache.openjpa.kernel.FetchConfiguration;
import org.apache.openjpa.kernel.FinderQuery;
import org.apache.openjpa.kernel.OpenJPAStateManager;
import org.apache.openjpa.kernel.StoreManager;
import org.apache.openjpa.meta.FieldMetaData;
import org.apache.openjpa.util.ApplicationIds;
import org.apache.openjpa.util.Id;
/**
* Implements Finder Query identified by ClassMappping for SelectExecutor that
* can be executed to generate Result.
*
* @author Pinaki Poddar
*
* @since 2.0.0
*/
public class FinderQueryImpl
implements FinderQuery<ClassMapping, SelectExecutor, Result> {
private final ClassMapping _mapping;
private final SelectImpl _select;
private final Column[] _pkCols;
private final Joinable[] _joins;
private final int[] _pkIndices;
private final SQLBuffer _buffer;
private final String _sql;
/**
* Attempts to construct a FinderQuery from the given Select for the given
* mapping. The given Select may not be amenable for caching and then a null
* value is returned.
*/
static FinderQueryImpl newFinder(ClassMapping mapping,
SelectExecutor select) {
SelectImpl impl = extractImplementation(select);
if (impl == null)
return null;
SQLBuffer buffer = impl.getSQL();
Column[] pkCols = mapping.getPrimaryKeyColumns();
//OPENJPA-2557: Typically the number of pkCols (length) should match the number (size) of
//parameters. However, there are a few cases (e.g. when extra parameters are needed for
//discriminator data) where the pkCols length may be different than the parameters.
//If we find the number of pkCols is equal to the number of parameters, we need to do
//one last check to verify that the buffers columns match the pkCols exactly.
boolean canCache = (pkCols.length == buffer.getParameters().size());
for(int i=0; i < pkCols.length && canCache; i++){
canCache = canCache && buffer.getColumns().contains(pkCols[i]);
}
return (canCache)
? new FinderQueryImpl(mapping, impl, buffer) : null;
}
private FinderQueryImpl(ClassMapping mapping, SelectImpl select,
SQLBuffer buffer) {
super();
_mapping = mapping;
_select = select;
_buffer = buffer;
_sql = _buffer.getSQL();
_pkCols = _mapping.getPrimaryKeyColumns();
_joins = new Joinable[_pkCols.length];
for (int i = 0; i < _pkCols.length; i++)
_joins[i] = _mapping.assertJoinable(_pkCols[i]);
_pkIndices = new int[_pkCols.length];
for (int i = 0; i < _pkCols.length; i++) {
FieldMetaData pk = _mapping.getField(_joins[i].getFieldIndex());
_pkIndices[i] = pk == null ? 0 : pk.getPrimaryKeyIndex();
}
}
public ClassMapping getIdentifier() {
return _mapping;
}
public SelectExecutor getDelegate() {
return _select;
}
public String getQueryString() {
return _sql;
}
public Column[] getPKColumns() {
return _pkCols;
}
private Object[] getPKValues(OpenJPAStateManager sm, JDBCStore store) {
Object[] pks = null;
Object oid = sm.getObjectId();
if (_mapping.getIdentityType() == ClassMapping.ID_APPLICATION)
pks = ApplicationIds.toPKValues(oid, _mapping);
Object[] val = new Object[_pkCols.length];
int count = 0;
for (int i = 0; i < _pkCols.length; i++, count++) {
if (pks == null)
val[0] = (oid == null)
? null : ((Id) oid).getId();
else {
val[i] = _joins[i].getJoinValue(pks[_pkIndices[i]], _pkCols[i],
store);
}
}
return val;
}
public Result execute(OpenJPAStateManager sm, StoreManager store,
FetchConfiguration fetch) {
boolean forUpdate = false;
JDBCStore jstore = (JDBCStore)store;
Connection conn = jstore.getConnection();
DBDictionary dict = jstore.getDBDictionary();
PreparedStatement stmnt = null;
ResultSet rs = null;
try {
stmnt = _select.prepareStatement(conn, _sql);
Object[] params = getPKValues(sm, jstore);
if (stmnt != null) {
for (int i = 0; i <params.length; i++) {
dict.setUnknown(stmnt, i+1, params[i], _pkCols[i]);
}
}
dict.setTimeouts(stmnt, (JDBCFetchConfiguration)fetch, forUpdate);
rs = _select.executeQuery(conn, stmnt, getQueryString(), jstore,
params, _pkCols);
return _select.getEagerResult(conn, stmnt, rs, jstore,
(JDBCFetchConfiguration)fetch, forUpdate, _buffer);
} catch (SQLException se) {
if (stmnt != null)
try { stmnt.close(); } catch (SQLException se2) {}
try { conn.close(); } catch (SQLException se2) {}
throw new RuntimeException(se);
}
}
private static SelectImpl extractImplementation(SelectExecutor selector) {
if (selector == null || selector.hasMultipleSelects())
return null;
if (selector instanceof SelectImpl)
return (SelectImpl)selector;
if (selector instanceof LogicalUnion.UnionSelect)
return ((LogicalUnion.UnionSelect)selector).getDelegate();
if (selector instanceof Union)
return extractImplementation(((Union)selector).getSelects()[0]);
return null;
}
public String toString() {
return _mapping + ": [" + getQueryString() + "]";
}
}