/***
* Copyright (c) 2009 Caelum - www.caelum.com.br/opensource
* All rights reserved.
*
* 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 br.com.caelum.vraptor.http.ognl;
import static com.google.common.base.Predicates.containsPattern;
import static com.google.common.collect.Maps.filterKeys;
import java.lang.reflect.Array;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.ResourceBundle;
import java.util.TreeMap;
import javax.servlet.http.HttpServletRequest;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import br.com.caelum.vraptor.converter.ConversionError;
import br.com.caelum.vraptor.http.InvalidParameterException;
import br.com.caelum.vraptor.http.ParameterNameProvider;
import br.com.caelum.vraptor.http.ParametersProvider;
import br.com.caelum.vraptor.ioc.Container;
import br.com.caelum.vraptor.ioc.RequestScoped;
import br.com.caelum.vraptor.resource.ResourceMethod;
import br.com.caelum.vraptor.validator.Message;
import br.com.caelum.vraptor.validator.ValidationMessage;
import com.google.common.base.Defaults;
/**
* Provides parameters using ognl to parse expression values into parameter
* values.
*
* @author guilherme silveira
*/
@RequestScoped
public class OgnlParametersProvider implements ParametersProvider {
private final ParameterNameProvider provider;
private static final Logger logger = LoggerFactory.getLogger(OgnlParametersProvider.class);
private final HttpServletRequest request;
private final Container container;
private final OgnlFacade ognl;
public OgnlParametersProvider(ParameterNameProvider provider,
HttpServletRequest request, Container container, OgnlFacade ognl) {
this.provider = provider;
this.request = request;
this.container = container;
this.ognl = ognl;
}
public Object[] getParametersFor(ResourceMethod method, List<Message> errors, ResourceBundle bundle) {
String[] names = provider.parameterNamesFor(method.getMethod());
Type[] types = method.getMethod().getGenericParameterTypes();
Class[] classes = method.getMethod().getParameterTypes();
Object[] result = new Object[types.length];
for (int i = 0; i < types.length; i++) {
Map<String, String[]> requestNames = parametersThatStartWith(names[i]);
result[i] = createParameter(new Parameter(types[i], classes[i], names[i], method), requestNames, bundle, errors);
}
return result;
}
protected static class Parameter {
public Type type;
public Class clazz;
public String name;
public ResourceMethod method;
public Parameter(Type type, Class clazz, String name, ResourceMethod method) {
this.type = type;
this.clazz = clazz;
this.name = name;
this.method = method;
}
public Class actualType() {
if (type instanceof TypeVariable) {
ParameterizedType superclass = (ParameterizedType) method.getResource().getType().getGenericSuperclass();
return (Class) superclass.getActualTypeArguments()[0];
}
return clazz;
}
}
protected Object createParameter(Parameter param, Map<String, String[]> requestNames, ResourceBundle bundle, List<Message> errors) {
Object root;
if (request.getAttribute(param.name) != null) {
return request.getAttribute(param.name);
} else if (param.clazz.isInterface() && container.canProvide(param.clazz)) {
return container.instanceFor(param.clazz);
} else if (requestNames.isEmpty()) {
return Defaults.defaultValue(param.actualType());
} else {
root = createRoot(param, requestNames, bundle, errors);
if (root == null) {
return null;
}
}
ognl.startContext(param.name, param.type, root, bundle);
for (Entry<String, String[]> parameter : requestNames.entrySet()) {
String key = parameter.getKey().replaceFirst('^' + param.name + "\\.?", "");
String[] values = parameter.getValue();
setProperty(param.name, key, values, errors);
}
return ognl.get(param.name);
}
protected Object createRoot(Parameter param, Map<String, String[]> requestNames, ResourceBundle bundle,
List<Message> errors) {
if (requestNames.containsKey(param.name)) {
String[] values = requestNames.get(param.name);
try {
return createSimpleParameter(param, values, bundle);
} catch(ConversionError ex) {
errors.add(new ValidationMessage(ex.getMessage(), param.name));
return null;
}
}
try {
return ognl.nullHandler().instantiate(param.actualType());
} catch (Exception ex) {
throw new InvalidParameterException("unable to instantiate type " + param.type, ex);
}
}
protected void setProperty(String name, String key, String[] values, List<Message> errors) {
try {
logger.debug("Applying {} with {}",key, values);
ognl.setValue(name, key, values);
} catch (ConversionError ex) {
errors.add(new ValidationMessage(ex.getMessage(), key));
}
}
protected Object createSimpleParameter(Parameter param, String[] values, ResourceBundle bundle) {
if (param.actualType().isArray()) {
return createArray(param.actualType(), values, bundle);
}
if (List.class.isAssignableFrom(param.actualType())) {
return createList(param.type, bundle, values);
}
return convert(param.actualType(), values[0], bundle);
}
protected Object convert(Class clazz, String value, ResourceBundle bundle) {
return ognl.createAdapter(bundle).convert(value, clazz);
}
protected List createList(Type type, ResourceBundle bundle, String[] values) {
List list = new ArrayList();
Class actual = getActualType(type);
for (String value : values) {
list.add(convert(actual, value, bundle));
}
return list;
}
protected Object createArray(Class clazz, String[] values, ResourceBundle bundle) {
Class arrayType = clazz.getComponentType();
Object array = Array.newInstance(arrayType, values.length);
for (int i = 0; i < values.length; i++) {
Array.set(array, i, convert(arrayType, values[i], bundle));
}
return array;
}
protected Class getActualType(Type type) {
return (Class) ((ParameterizedType) type).getActualTypeArguments()[0];
}
protected Map<String, String[]> parametersThatStartWith(String name) {
Map<String, String[]> requestNames = filterKeys(request.getParameterMap(), containsPattern('^' + name));
return new TreeMap<String, String[]>(requestNames);
}
}