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* 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.conf;
import java.io.InputStream;
import javax.sql.DataSource;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.cayenne.ConfigurationException;
import org.apache.cayenne.access.ConnectionLogger;
import org.apache.cayenne.access.QueryLogger;
import org.apache.cayenne.conn.DataSourceInfo;
import org.apache.cayenne.conn.PoolManager;
import org.apache.cayenne.util.Util;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
/**
* Creates DataSource objects from XML configuration files that describe a JDBC driver.
* Wraps JDBC driver in a generic DataSource implementation.
*
* @author Andrei Adamchik
*/
// TODO: factory shouldn't contain any state specific to location ("driverInfo" ivar
// should go, and probably "parser" too)... Otherwise the API doesn't make sense -
// sequential invocations of getDataSource() will have side effects....
public class DriverDataSourceFactory implements DataSourceFactory {
private static Logger logObj = Logger.getLogger(DriverDataSourceFactory.class);
protected XMLReader parser;
protected DataSourceInfo driverInfo;
protected Configuration parentConfiguration;
/**
* Creates new DriverDataSourceFactory.
*/
public DriverDataSourceFactory() throws Exception {
this.parser = Util.createXmlReader();
}
/**
* Stores configuration object internally to use it later for resource loading.
*/
public void initializeWithParentConfiguration(Configuration parentConfiguration) {
this.parentConfiguration = parentConfiguration;
}
/**
* @deprecated since 1.2
*/
public DataSource getDataSource(String location, Level logLevel) throws Exception {
return this.getDataSource(location);
}
public DataSource getDataSource(String location) throws Exception {
this.load(location);
ConnectionLogger logger = new ConnectionLogger();
try {
return new PoolManager(driverInfo.getJdbcDriver(), driverInfo
.getDataSourceUrl(), driverInfo.getMinConnections(), driverInfo
.getMaxConnections(), driverInfo.getUserName(), driverInfo
.getPassword(), logger);
}
catch (Exception ex) {
QueryLogger.logConnectFailure(ex);
throw ex;
}
}
/**
* Returns DataSourceInfo property.
*/
protected DataSourceInfo getDriverInfo() {
return this.driverInfo;
}
protected InputStream getInputStream(String location) {
if (this.parentConfiguration == null) {
throw new ConfigurationException(
"No parent Configuration set - cannot continue.");
}
return this.parentConfiguration.getResourceLocator().findResourceStream(location);
}
/**
* Loads driver information from the file at <code>location</code>. Called
* internally from "getDataSource"
*/
protected void load(String location) throws Exception {
logObj.info("loading driver information from '" + location + "'.");
InputStream in = this.getInputStream(location);
if (in == null) {
logObj.info("Error: location '" + location + "' not found.");
throw new ConfigurationException(
"Can't find DataSource configuration file at " + location);
}
RootHandler handler = new RootHandler();
parser.setContentHandler(handler);
parser.setErrorHandler(handler);
parser.parse(new InputSource(in));
}
// SAX handlers start below
/** Handler for the root element. Its only child must be the "driver" element. */
private class RootHandler extends DefaultHandler {
/**
* Handles the start of a "driver" element. A driver handler is created and
* initialized with the element name and attributes.
*
* @exception SAXException if the tag given is not <code>"driver"</code>
*/
public void startElement(
String namespaceURI,
String localName,
String qName,
Attributes atts) throws SAXException {
if (localName.equals("driver")) {
new DriverHandler(parser, this).init(localName, atts);
}
else {
logObj.info( "<driver> must be the root element. <"
+ localName
+ "> is unexpected.");
throw new SAXException("Config file is not of expected XML type. '"
+ localName
+ "' unexpected.");
}
}
}
/** Handler for the "driver" element. */
private class DriverHandler extends AbstractHandler {
public DriverHandler(XMLReader parser, ContentHandler parentHandler) {
super(parser, parentHandler);
}
public void init(String name, Attributes attrs) {
String className = attrs.getValue("", "class");
logObj.info( "loading driver " + className);
driverInfo = new DataSourceInfo();
driverInfo.setJdbcDriver(className);
}
/**
* Handles the start of a driver child element. An appropriate handler is created
* and initialized with the element name and attributes.
*
* @exception SAXException if the tag given is not recognized.
*/
public void startElement(
String namespaceURI,
String localName,
String qName,
Attributes atts) throws SAXException {
if (localName.equals("login")) {
new LoginHandler(this.parser, this).init(localName, atts, driverInfo);
}
else if (localName.equals("url")) {
new UrlHandler(this.parser, this).init(localName, atts, driverInfo);
}
else if (localName.equals("connectionPool")) {
new ConnectionHandler(this.parser, this)
.init(localName, atts, driverInfo);
}
else {
logObj.info( "<login, url, connectionPool> are valid. <"
+ localName
+ "> is unexpected.");
throw new SAXException("Config file is not of expected XML type");
}
}
}
private class UrlHandler extends AbstractHandler {
/**
* Constructor which just delegates to the superconstructor.
*
* @param parentHandler The handler which should be restored to the parser at the
* end of the element. Must not be <code>null</code>.
*/
public UrlHandler(XMLReader parser, ContentHandler parentHandler) {
super(parser, parentHandler);
}
public void init(String name, Attributes atts, DataSourceInfo driverInfo)
throws SAXException {
driverInfo.setDataSourceUrl(atts.getValue("value"));
if (driverInfo.getDataSourceUrl() == null) {
logObj.info( "error: <url> has no 'value'.");
throw new SAXException("'<url value=' attribute is required.");
}
}
}
private class LoginHandler extends AbstractHandler {
/**
* Constructor which just delegates to the superconstructor.
*
* @param parentHandler The handler which should be restored to the parser at the
* end of the element. Must not be <code>null</code>.
*/
public LoginHandler(XMLReader parser, ContentHandler parentHandler) {
super(parser, parentHandler);
}
public void init(String name, Attributes atts, DataSourceInfo driverInfo) {
logObj.info("loading user name and password.");
driverInfo.setUserName(atts.getValue("userName"));
driverInfo.setPassword(atts.getValue("password"));
}
}
private class ConnectionHandler extends AbstractHandler {
/**
* Constructor which just delegates to the superconstructor.
*
* @param parentHandler The handler which should be restored to the parser at the
* end of the element. Must not be <code>null</code>.
*/
public ConnectionHandler(XMLReader parser, ContentHandler parentHandler) {
super(parser, parentHandler);
}
public void init(String name, Attributes atts, DataSourceInfo driverInfo)
throws SAXException {
try {
String min = atts.getValue("min");
if (min != null)
driverInfo.setMinConnections(Integer.parseInt(min));
String max = atts.getValue("max");
if (max != null)
driverInfo.setMaxConnections(Integer.parseInt(max));
}
catch (NumberFormatException nfex) {
logObj.info( "Error loading numeric attribute", nfex);
throw new SAXException("Error reading numeric attribute.", nfex);
}
}
}
}