/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.data.oracle;
import java.lang.reflect.Method;
import org.geotools.factory.Hints;
import org.geotools.util.Converter;
import org.geotools.util.ConverterFactory;
public class OracleClobConverterFactory implements ConverterFactory {
OracleDateConverter converter = new OracleDateConverter();
static final Class<?> ORA_CLOB;
static final Method ORA_GET_CHARS;
static final Method ORA_LENGTH;
static {
Class<?> oracleClobClass = null;
try {
oracleClobClass = Class.forName("oracle.sql.CLOB");
} catch (ClassNotFoundException e) {
// ojdbc*.jar not on the path
}
if (oracleClobClass == null) {
ORA_CLOB = null;
ORA_GET_CHARS = null;
ORA_LENGTH = null;
} else {
try {
ORA_CLOB = oracleClobClass;
ORA_LENGTH = ORA_CLOB.getMethod("length");
ORA_GET_CHARS = ORA_CLOB.getMethod("getChars", long.class, int.class, char[].class);
} catch(Exception e) {
throw new RuntimeException("Could not initialize the oracle blob converter", e);
}
}
}
public Converter createConverter(Class<?> source, Class<?> target,
Hints hints) {
// if the jdbc driver is not in the classpath don't bother trying to convert
if(ORA_CLOB == null)
return null;
// can only convert towards String
if (!(String.class.equals(target)))
return null;
// can only deal with oracle specific blob classes
if (!ORA_CLOB.isAssignableFrom(source))
return null;
// converter is thread safe, so cache and return just one
return converter;
}
class OracleDateConverter implements Converter {
public <T> T convert(Object source, Class<T> target) throws Exception {
int length = ((Long) ORA_LENGTH.invoke(source)).intValue();
char[] buffer = new char[length];
ORA_GET_CHARS.invoke(source, 1l, length, buffer);
return (T) new String(buffer);
}
}
}