org.apache.cayenne.access.trans.LOBBatchQueryWrapper Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of cayenne-client-nodeps
Show all versions of cayenne-client-nodeps
Cayenne Object Persistence Framework
/*****************************************************************
* 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.cayenne.access.trans;
import java.sql.Types;
import java.util.ArrayList;
import java.util.List;
import org.apache.cayenne.map.DbAttribute;
import org.apache.cayenne.query.BatchQuery;
/**
* Helper class to extract the information from BatchQueries, essential for LOB columns
* processing.
*
* @author Andrei Adamchik
*/
public class LOBBatchQueryWrapper {
protected BatchQuery query;
protected List dbAttributes;
// attribute list decoders
protected boolean[] qualifierAttributes;
protected boolean[] allLOBAttributes;
protected Object[] updatedLOBAttributes;
protected boolean hasNext;
public LOBBatchQueryWrapper(BatchQuery query) {
this.query = query;
this.dbAttributes = query.getDbAttributes();
int len = dbAttributes.size();
this.qualifierAttributes = new boolean[len];
this.allLOBAttributes = new boolean[len];
this.updatedLOBAttributes = new Object[len];
indexQualifierAttributes();
}
public boolean next() {
hasNext = query.next();
if (hasNext) {
indexLOBAttributes();
}
return hasNext;
}
/**
* Indexes attributes
*/
protected void indexQualifierAttributes() {
int len = this.dbAttributes.size();
for (int i = 0; i < len; i++) {
DbAttribute attribute = (DbAttribute) this.dbAttributes.get(i);
int type = attribute.getType();
qualifierAttributes[i] = attribute.isPrimaryKey();
allLOBAttributes[i] = (type == Types.BLOB || type == Types.CLOB);
}
}
/**
* Indexes attributes
*/
protected void indexLOBAttributes() {
int len = updatedLOBAttributes.length;
for (int i = 0; i < len; i++) {
updatedLOBAttributes[i] = null;
if (allLOBAttributes[i]) {
// skip null and empty LOBs
Object value = query.getValue(i);
if (value == null) {
continue;
}
if (((DbAttribute) dbAttributes.get(i)).getType() == Types.BLOB) {
updatedLOBAttributes[i] = convertToBlobValue(value);
}
else {
updatedLOBAttributes[i] = convertToClobValue(value);
}
}
}
}
/**
* Converts value to byte[] if possible.
*/
protected byte[] convertToBlobValue(Object value) {
if (value instanceof byte[]) {
byte[] bytes = (byte[]) value;
return bytes.length == 0 ? null : bytes;
}
return null;
}
/**
* Converts to char[] or String. Both are acceptable when writing CLOBs.
*/
protected Object convertToClobValue(Object value) {
if (value instanceof char[]) {
char[] chars = (char[]) value;
return (chars.length == 0) ? null : chars;
}
else {
String strValue = value.toString();
return (strValue.length() == 0) ? null : strValue;
}
}
/**
* Returns a list of DbAttributes used in the qualifier of the query that selects a
* LOB row for LOB update.
*/
public List getDbAttributesForLOBSelectQualifier() {
int len = qualifierAttributes.length;
List attributes = new ArrayList(len);
for (int i = 0; i < len; i++) {
if (this.qualifierAttributes[i]) {
attributes.add(this.dbAttributes.get(i));
}
}
return attributes;
}
/**
* Returns a list of DbAttributes that correspond to the LOB columns updated in the
* current row in the batch query. The list will not include LOB attributes that are
* null or empty.
*/
public List getDbAttributesForUpdatedLOBColumns() {
if (!hasNext) {
throw new IllegalStateException("No more rows in the BatchQuery.");
}
int len = updatedLOBAttributes.length;
List attributes = new ArrayList(len);
for (int i = 0; i < len; i++) {
if (this.updatedLOBAttributes[i] != null) {
attributes.add(this.dbAttributes.get(i));
}
}
return attributes;
}
public List getValuesForLOBSelectQualifier() {
if (!hasNext) {
throw new IllegalStateException("No more rows in the BatchQuery.");
}
int len = this.qualifierAttributes.length;
List values = new ArrayList(len);
for (int i = 0; i < len; i++) {
if (this.qualifierAttributes[i]) {
values.add(query.getValue(i));
}
}
return values;
}
public List getValuesForUpdatedLOBColumns() {
if (!hasNext) {
throw new IllegalStateException("No more rows in the BatchQuery.");
}
int len = this.updatedLOBAttributes.length;
List values = new ArrayList(len);
for (int i = 0; i < len; i++) {
if (this.updatedLOBAttributes[i] != null) {
values.add(this.updatedLOBAttributes[i]);
}
}
return values;
}
/**
* Returns wrapped BatchQuery.
*/
public BatchQuery getQuery() {
return query;
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy