/*
* Copyright 2012-2013 Hauser Olsson GmbH
*
* 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 ch.agent.crnickl.mongodb;
import java.util.ArrayList;
import java.util.Collection;
import java.util.regex.Pattern;
import org.bson.types.ObjectId;
import ch.agent.crnickl.T2DBException;
import ch.agent.crnickl.T2DBMsg;
import ch.agent.crnickl.T2DBMsg.E;
import ch.agent.crnickl.api.DBObjectType;
import ch.agent.crnickl.api.Database;
import ch.agent.crnickl.api.Property;
import ch.agent.crnickl.api.Surrogate;
import ch.agent.crnickl.api.ValueType;
import ch.agent.crnickl.impl.PropertyImpl;
import ch.agent.crnickl.mongodb.T2DBMMsg.J;
import com.mongodb.BasicDBObject;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
/**
* A stateless object with methods providing read access to properties.
*
* @author Jean-Paul Vetterli
*/
public class ReadMethodsForProperty extends MongoDatabaseMethods {
public ReadMethodsForProperty() {
}
/**
* Find a property by its name in a database.
*
* @param database a database
* @param name a string
* @return a property or null
* @throws T2DBException
*/
public <T>Property<T> getProperty(Database database, String name) throws T2DBException {
try {
DBCollection coll = getMongoDB(database).getProperties();
DBObject obj = coll.findOne(mongoObject(MongoDatabase.FLD_PROP_NAME, name));
if (obj != null)
return unpack(database, (BasicDBObject) obj);
else
return null;
} catch (Exception e) {
throw T2DBMsg.exception(e, E.E20104, name);
}
}
/**
* Find a collection of properties with names matching a pattern.
* If the pattern is enclosed in slashes it is taken as a standard
* regexp pattern; the slashes will be removed. If it is not enclosed
* in slashes, it is taken as a minimal pattern and all occurrences of
* "*" will be replaced with ".*" (zero or more arbitrary characters).
*
* @param database a database
* @param pattern a simple pattern or a regexp pattern
* @return a collection of properties, possibly empty, never null
* @throws T2DBException
*/
public Collection<Property<?>> getProperties(Database database, String pattern) throws T2DBException {
try {
DBCollection coll = getMongoDB(database).getProperties();
DBObject query = null;
if (pattern != null && pattern.length() > 0) {
String regexp = extractRegexp(pattern);
if (regexp == null)
pattern = pattern.replace("*", ".*");
else
pattern = regexp;
query = mongoObject(MongoDatabase.FLD_PROP_NAME, Pattern.compile(pattern));
}
DBCursor cursor = coll.find(query);
Collection<Property<?>> result = new ArrayList<Property<?>>();
try {
while (cursor.hasNext()) {
result.add(unpack(database, (BasicDBObject) cursor.next()));
}
} finally {
cursor.close();
}
return result;
} catch (Exception e) {
throw T2DBMsg.exception(e, E.E20106, pattern);
}
}
/**
* Find a property corresponding to a surrogate.
*
* @param s a surrogate
* @return a property or null
* @throws T2DBException
*/
public <T>Property<T> getProperty(Surrogate s) throws T2DBException {
try {
DBObject obj = getObject(s, false);
if (obj != null)
return unpack(s.getDatabase(), (BasicDBObject) obj);
else
return null;
} catch (Exception e) {
throw T2DBMsg.exception(e, E.E20105, s.toString());
}
}
private <T>Property<T> unpack(Database db, BasicDBObject obj) throws T2DBException {
try {
ObjectId id = obj.getObjectId(MongoDatabase.FLD_ID);
String name = obj.getString(MongoDatabase.FLD_PROP_NAME);
ObjectId vtId = obj.getObjectId(MongoDatabase.FLD_PROP_VT);
Boolean indexed = obj.getBoolean(MongoDatabase.FLD_PROP_INDEXED);
Surrogate vts = makeSurrogate(db, DBObjectType.VALUE_TYPE, new MongoDBObjectId(vtId));
ValueType<T> vt = db.getValueType(vts);
Surrogate s = makeSurrogate(db, DBObjectType.PROPERTY, new MongoDBObjectId(id));
checkIntegrity(vt, vts, s);
return new PropertyImpl<T>(name, vt, indexed, s);
} catch (ClassCastException e) {
throw T2DBMMsg.exception(e, J.J81010, obj.toString());
}
}
}