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* 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
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* KIND, either express or implied. See the License for the
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package org.apache.cayenne.configuration.server;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.SQLException;
import java.util.List;
import javax.sql.DataSource;
import org.apache.cayenne.CayenneRuntimeException;
import org.apache.cayenne.access.QueryLogger;
import org.apache.cayenne.configuration.AdhocObjectFactory;
import org.apache.cayenne.configuration.DataNodeDescriptor;
import org.apache.cayenne.dba.AutoAdapter;
import org.apache.cayenne.dba.DbAdapter;
import org.apache.cayenne.dba.JdbcAdapter;
import org.apache.cayenne.di.Inject;
import org.apache.cayenne.di.Provider;
import org.apache.cayenne.log.JdbcEventLogger;
/**
* A factory of DbAdapters that either loads user-provided adapter or guesses the adapter
* type from the database metadata.
*
* @since 3.1
*/
public class DefaultDbAdapterFactory implements DbAdapterFactory {
public static final String DETECTORS_LIST = "org.apache.cayenne.configuration.server.DefaultDbAdapterFactory.detectors";
@Inject
protected JdbcEventLogger jdbcEventLogger;
@Inject
protected AdhocObjectFactory objectFactory;
protected List<DbAdapterDetector> detectors;
public DefaultDbAdapterFactory(
@Inject(DETECTORS_LIST) List<DbAdapterDetector> detectors) {
if (detectors == null) {
throw new NullPointerException("Null detectors list");
}
this.detectors = detectors;
}
public DbAdapter createAdapter(
final DataNodeDescriptor nodeDescriptor,
final DataSource dataSource) throws Exception {
String adapterType = nodeDescriptor.getAdapterType();
if (adapterType != null) {
return objectFactory.newInstance(DbAdapter.class, adapterType);
}
else {
return new AutoAdapter(new Provider<DbAdapter>() {
public DbAdapter get() {
return detectAdapter(nodeDescriptor, dataSource);
}
});
}
}
protected DbAdapter detectAdapter(
DataNodeDescriptor nodeDescriptor,
DataSource dataSource) {
if (detectors.isEmpty()) {
return defaultAdapter();
}
try {
Connection c = dataSource.getConnection();
try {
return detectAdapter(c.getMetaData());
}
finally {
try {
c.close();
}
catch (SQLException e) {
// ignore...
}
}
}
catch (SQLException e) {
throw new CayenneRuntimeException("Error detecting database type: "
+ e.getLocalizedMessage(), e);
}
}
protected DbAdapter detectAdapter(DatabaseMetaData metaData) throws SQLException {
// iterate in reverse order to allow custom factories to take precedence over the
// default ones configured in constructor
for (int i = detectors.size() - 1; i >= 0; i--) {
DbAdapterDetector detector = detectors.get(i);
DbAdapter adapter = detector.createAdapter(metaData);
if (adapter != null) {
jdbcEventLogger.log("Detected and installed adapter: "
+ adapter.getClass().getName());
return adapter;
}
}
return defaultAdapter();
}
protected DbAdapter defaultAdapter() {
jdbcEventLogger.log("Failed to detect database type, using generic adapter");
return new JdbcAdapter();
}
}