org.zdevra.guice.mvc.ConversionService Maven / Gradle / Ivy
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/*****************************************************************************
* Copyright 2012 Zdenko Vrabel
*
* Licensed 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.zdevra.guice.mvc;
import java.lang.annotation.Annotation;
import java.util.Collection;
import java.util.Map;
import java.util.Set;
import org.zdevra.guice.mvc.converters.NoConverterFactory;
import org.zdevra.guice.mvc.exceptions.NoConverterException;
import com.google.inject.Inject;
import com.google.inject.Singleton;
/**
* The class provides conversions from incomming strings from HTTP requests
* to a various datatypes.
*
* The class is used internally by {@link MethodInvokerImpl}.
*
* You may implement and register your own converter. Just
* implements the {@link ConversionService.Converter}, {@link ConversionService.ConverterFactory}
* interfaces and in your configureControllers() register the converter:
*
*
* class MyModule extends MvcModule {
*
* protected void configureControllers() {
* ...
* registerConverter(MyConverterFactory.class);
* ...
* }
* }
*
*
* All supported converters in Lime are placed in package {@link org.zdevra.guice.mvc.converters}.
*
* @see ConversionService.Converter
* @see ConversionService.ConverterFactory
*/
@Singleton
public class ConversionService {
/*---------------------------- m. variables ----------------------------*/
private final Collection factories;
/*----------------------------------------------------------------------*/
/**
* Interface for converter
*/
public interface Converter {
public T convert(String name, Map data);
}
/**
* Interface for contertor factory which is constructing converter impl.
*
*/
public interface ConverterFactory {
public Converter createConverter(Class type, Annotation[] annotations);
}
/*---------------------------- constructors ----------------------------*/
/**
* Constructor
*/
@Inject
public ConversionService(Set factories) {
this.factories = factories;
}
/*------------------------------- methods ------------------------------*/
/**
* Method return right converter for type
*
* @param type
* @return
*/
public Converter getConverter(Class type, Annotation[] annotations)
{
for (ConverterFactory factory : factories) {
Converter converter = factory.createConverter(type, annotations);
if (converter != null) {
return converter;
}
}
throw new NoConverterException(type);
}
/**
* Method return converter from given factory class. If factory class is {@link NoConverterFactory}, then
* is called origin method of getConverter()
*/
public Converter getConverter(Class converterFactoryClass, Class type, Annotation[] annotations)
{
if (converterFactoryClass == NoConverterFactory.class) {
return getConverter(type, annotations);
}
for (ConverterFactory factory : factories) {
if (factory.getClass() == converterFactoryClass) {
Converter converter = factory.createConverter(type, annotations);
if (converter != null) {
return converter;
}
}
}
throw new NoConverterException(converterFactoryClass, type);
}
/*----------------------------------------------------------------------*/
}