package com.nearinfinity.hbase.dsl;
/**
* 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.util.HashMap;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import com.nearinfinity.hbase.dsl.types.BigDecimalConverter;
import com.nearinfinity.hbase.dsl.types.BigIntegerConverter;
import com.nearinfinity.hbase.dsl.types.BooleanConverter;
import com.nearinfinity.hbase.dsl.types.ByteArrayConverter;
import com.nearinfinity.hbase.dsl.types.DateConverter;
import com.nearinfinity.hbase.dsl.types.DoubleConverter;
import com.nearinfinity.hbase.dsl.types.FloatConverter;
import com.nearinfinity.hbase.dsl.types.IntConverter;
import com.nearinfinity.hbase.dsl.types.LongConverter;
import com.nearinfinity.hbase.dsl.types.ShortConverter;
import com.nearinfinity.hbase.dsl.types.StringConverter;
import com.nearinfinity.hbase.dsl.types.TypeConverter;
/**
* This class is responsible for converting objects to binary and back again.
* Internally it uses a hash map, so it is not thread safe while changing the
* types. Once setup though, it is thread safe.
*
* @author Aaron McCurry
*/
@SuppressWarnings("unchecked")
public class TypeDriver {
private static final Log LOG = LogFactory.getLog(TypeDriver.class);
private Map<Class<?>, TypeConverter<?>> converters = new HashMap<Class<?>, TypeConverter<?>>();
/**
* This method registers all know type converters.
*
* @return this.
*/
public TypeDriver registerAllKnownTypes() {
registerType(new BigDecimalConverter());
registerType(new BigIntegerConverter());
registerType(new StringConverter());
registerType(new IntConverter());
registerType(new DoubleConverter());
registerType(new BooleanConverter());
registerType(new FloatConverter());
registerType(new LongConverter());
registerType(new ShortConverter());
registerType(new DateConverter());
registerType(new ByteArrayConverter());
return this;
}
/**
* Converts the object to binary.
*
* @param o
* the object, can not be null.
* @return the binary.
*/
public byte[] toBytes(Object o) {
TypeConverter<Object> typeConverter = (TypeConverter<Object>) converters.get(o.getClass());
if (typeConverter == null) {
for (Class<?> c : converters.keySet()) {
LOG.info("Known type [" + c + "]");
}
throw new RuntimeException("No type found for class [" + o.getClass() + "]");
}
return typeConverter.toBytes(o);
}
/**
* Convert the binary back into an object.
*
* @param <U>
* the type of the new object.
* @param value
* the binary.
* @param cl
* the class type of the new object.
* @return the new object.
*/
public <U> U fromBytes(byte[] value, Class<U> cl) {
TypeConverter<U> typeConverter = (TypeConverter<U>) converters.get(cl);
if (typeConverter == null) {
for (Class<?> c : converters.keySet()) {
LOG.info("Known type [" + c + "]");
}
throw new RuntimeException("No type found for class [" + cl + "]");
}
return typeConverter.fromBytes(value);
}
/**
* Registers a single type converter into this driver.
*
* @param converter
* the new converter.
* @return this.
*/
public TypeDriver registerType(TypeConverter<?> converter) {
for (Class<?> c : converter.getTypes()) {
LOG.info("Registering type [" + c + "]");
converters.put(c, converter);
}
return this;
}
}