package org.apache.torque.engine.database.transform;
/*
* 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.
*/
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.torque.engine.database.model.Column;
import org.apache.torque.engine.database.model.Database;
import org.apache.torque.engine.database.model.Table;
import org.xml.sax.Attributes;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
/**
* A Class that is used to parse an input xml schema file and creates and
* AppData java structure.
*
* @author <a href="mailto:leon@opticode.co.za">Leon Messerschmidt</a>
* @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
* @author <a href="mailto:mpoeschl@marmot.at">Martin Poeschl</a>
* @author <a href="mailto:fedor.karpelevitch@home.com">Fedor Karpelevitch</a>
* @version $Id: XmlToData.java 473814 2006-11-11 22:30:30Z tv $
*/
public class XmlToData extends DefaultHandler implements EntityResolver
{
/** Logging class from commons.logging */
private static Log log = LogFactory.getLog(XmlToData.class);
private Database database;
private List data;
private String dtdFileName;
private File dtdFile;
private InputSource dataDTD;
private static SAXParserFactory saxFactory;
static
{
saxFactory = SAXParserFactory.newInstance();
saxFactory.setValidating(true);
}
/**
* Default custructor
*/
public XmlToData(Database database, String dtdFilePath)
throws MalformedURLException, IOException
{
this.database = database;
dtdFile = new File(dtdFilePath);
this.dtdFileName = "file://" + dtdFile.getName();
dataDTD = new InputSource(dtdFile.toURL().openStream());
}
/**
*
*/
public List parseFile(String xmlFile)
throws Exception
{
data = new ArrayList();
SAXParser parser = saxFactory.newSAXParser();
FileReader fr = new FileReader (xmlFile);
BufferedReader br = new BufferedReader (fr);
try
{
InputSource is = new InputSource (br);
parser.parse(is, this);
}
finally
{
br.close();
}
return data;
}
/**
* Handles opening elements of the xml file.
*/
public void startElement(String uri, String localName, String rawName,
Attributes attributes)
throws SAXException
{
try
{
if (rawName.equals("dataset"))
{
//ignore <dataset> for now.
}
else
{
Table table = database.getTableByJavaName(rawName);
if (table == null)
{
throw new SAXException("Table '" + rawName + "' unknown");
}
List columnValues = new ArrayList();
for (int i = 0; i < attributes.getLength(); i++)
{
Column col = table
.getColumnByJavaName(attributes.getQName(i));
if (col == null)
{
throw new SAXException("Column "
+ attributes.getQName(i) + " in table "
+ rawName + " unknown.");
}
String value = attributes.getValue(i);
columnValues.add(new ColumnValue(col, value));
}
data.add(new DataRow(table, columnValues));
}
}
catch (Exception e)
{
throw new SAXException(e);
}
}
/**
* called by the XML parser
*
* @return an InputSource for the database.dtd file
*/
public InputSource resolveEntity(String publicId, String systemId)
throws SAXException
{
try
{
if (dataDTD != null && dtdFileName.equals(systemId))
{
log.info("Resolver: used " + dtdFile.getPath());
return dataDTD;
}
else
{
log.info("Resolver: used " + systemId);
return getInputSource(systemId);
}
}
catch (IOException e)
{
throw new SAXException(e);
}
}
/**
* get an InputSource for an URL String
*
* @param urlString
* @return an InputSource for the URL String
*/
public InputSource getInputSource(String urlString)
throws IOException
{
URL url = new URL(urlString);
InputSource src = new InputSource(url.openStream());
return src;
}
/**
*
*/
public class DataRow
{
private Table table;
private List columnValues;
public DataRow(Table table, List columnValues)
{
this.table = table;
this.columnValues = columnValues;
}
public Table getTable()
{
return table;
}
public List getColumnValues()
{
return columnValues;
}
}
/**
*
*/
public class ColumnValue
{
private Column col;
private String val;
public ColumnValue(Column col, String val)
{
this.col = col;
this.val = val;
}
public Column getColumn()
{
return col;
}
public String getValue()
{
return val;
}
public String getEscapedValue()
{
StringBuffer sb = new StringBuffer();
sb.append("'");
sb.append(StringUtils.replace(val, "'", "''"));
sb.append("'");
return sb.toString();
}
}
}