org.apache.openjpa.jdbc.schema.LazySchemaFactory Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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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
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.openjpa.jdbc.schema;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.SQLException;
import org.apache.openjpa.jdbc.conf.JDBCConfiguration;
import org.apache.openjpa.jdbc.identifier.DBIdentifier;
import org.apache.openjpa.jdbc.identifier.QualifiedDBIdentifier;
import org.apache.openjpa.jdbc.sql.SQLExceptions;
import org.apache.openjpa.lib.conf.Configurable;
import org.apache.openjpa.lib.conf.Configuration;
/**
* Factory that uses database metadata to construct the system schema.
* The lazy schema factory only loads table data as it is requested. It
* does not properly support operations that require knowledge of the entire
* schema.
*
* @author Abe White
*/
public class LazySchemaFactory
extends SchemaGroup
implements SchemaFactory, Configurable {
private static final long serialVersionUID = 1L;
private transient JDBCConfiguration _conf = null;
private transient Connection _conn = null;
private transient DatabaseMetaData _meta = null;
private transient SchemaGenerator _gen = null;
private boolean _indexes = false;
private boolean _pks = false;
private boolean _fks = false;
public boolean getPrimaryKeys() {
return _pks;
}
public void setPrimaryKeys(boolean pks) {
_pks = pks;
}
public boolean getForeignKeys() {
return _fks;
}
public void setForeignKeys(boolean fks) {
_fks = fks;
}
public boolean getIndexes() {
return _indexes;
}
public void setIndexes(boolean idx) {
_indexes = idx;
}
@Override
public SchemaGroup readSchema() {
return this;
}
@Override
public void storeSchema(SchemaGroup schema) {
// nothing to do
}
/**
* @deprecated
*/
@Deprecated
@Override
public Table findTable(String name) {
if (name == null)
return null;
return findTable(DBIdentifier.newTable(name));
}
public Table findTable(DBIdentifier name) {
if (name == null)
return null;
return findTable(QualifiedDBIdentifier.getPath(name));
}
@Override
public Table findTable(QualifiedDBIdentifier path) {
if (path == null)
return null;
Table table = super.findTable(path);
if (table != null)
return table;
generateSchemaObject(path, true);
return super.findTable(path);
}
/**
* @deprecated
*/
@Deprecated
@Override
public Sequence findSequence(String name) {
if (name == null)
return null;
return findSequence(DBIdentifier.newSequence(name));
}
@Override
public Sequence findSequence(DBIdentifier name) {
if (name == null)
return null;
return findSequence(QualifiedDBIdentifier.getPath(name));
}
@Override
public Sequence findSequence(QualifiedDBIdentifier name) {
if (name == null)
return null;
Sequence seq = super.findSequence(name);
if (seq != null)
return seq;
generateSchemaObject(name, false);
return super.findSequence(name);
}
/**
* Generate the table or sequence with the given name.
*/
private void generateSchemaObject(QualifiedDBIdentifier name, boolean isTable) {
// if full name, split
DBIdentifier schemaName = name.getSchemaName();
DBIdentifier objectName = name.getIdentifier();
// we share a single connection across all schemas, so synch
// on the schema group
synchronized (this) {
boolean close = false;
try {
// use the existing connection if possible; this method
// might be reentrant if generating the foreign keys for
// this table (see below) requires loading additional
// tables; in that case we don't want to spawn additional
// connections
if (_conn == null) {
_conn = _conf.getDataSource2(null).getConnection();
close = true;
_meta = _conn.getMetaData();
}
if (isTable) {
// generate the table from database metadata
_gen.generateTables(schemaName, objectName, _conn, _meta);
Table table = super.findTable(name);
if (table != null) {
if (_pks)
_gen.generatePrimaryKeys(table.getSchemaIdentifier(),
table.getIdentifier(), _conn, _meta);
if (_indexes)
_gen.generateIndexes(table.getSchemaIdentifier(),
table.getIdentifier(), _conn, _meta);
// generate foreign keys from the table; this might
// end up re-calling this getTable method if the foreign
// key links to a table that hasn't been loaded yet
if (_fks)
_gen.generateForeignKeys(table.getSchemaIdentifier(),
table.getIdentifier(), _conn, _meta);
}
} else
_gen.generateSequences(schemaName, objectName, _conn,
_meta);
} catch (SQLException se) {
throw SQLExceptions.getStore(se,
_conf.getDBDictionaryInstance());
} finally {
if (close) {
try {
_conn.close();
} catch (SQLException se) {
}
_conn = null;
}
}
}
}
@Override
public void setConfiguration(Configuration conf) {
_conf = (JDBCConfiguration) conf;
_gen = new SchemaGenerator(_conf);
_gen.setSchemaGroup(this);
}
@Override
public void startConfiguration() {
}
@Override
public void endConfiguration() {
}
}