com.gwtplatform.dispatch.rest.client.DefaultRestResponseDeserializer Maven / Gradle / Ivy
/**
* Copyright 2013 ArcBees Inc.
*
* 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 com.gwtplatform.dispatch.rest.client;
import javax.inject.Inject;
import com.github.nmorel.gwtjackson.client.exception.JsonMappingException;
import com.google.gwt.http.client.Response;
import com.gwtplatform.dispatch.rest.client.serialization.Serialization;
import com.gwtplatform.dispatch.rest.shared.RestAction;
import com.gwtplatform.dispatch.shared.ActionException;
/**
* Default implementation for {@link RestResponseDeserializer}.
*/
public class DefaultRestResponseDeserializer implements RestResponseDeserializer {
private final ActionMetadataProvider metadataProvider;
private final Serialization serialization;
@Inject
protected DefaultRestResponseDeserializer(
ActionMetadataProvider metadataProvider,
Serialization serialization) {
this.metadataProvider = metadataProvider;
this.serialization = serialization;
}
@Override
public , R> R deserialize(A action, Response response) throws ActionException {
if (isSuccessStatusCode(response)) {
return getDeserializedResponse(action, response);
} else {
throw new ActionException(response.getStatusText());
}
}
/**
* Verify if the provided resultType can be deserialized.
*
* @param resultType the parameterized type to verify if it can be deserialized.
*
* @return true if resultType can be deserialized, false otherwise.
*/
protected boolean canDeserialize(String resultType) {
return serialization.canDeserialize(resultType);
}
/**
* Deserializes the json as an object of the resultType type.
*
* @param resultType the parameterized type of the object once deserialized.
* @param json the json to deserialize.
* @param the type of the object once deserialized
*
* @return The deserialized object.
*/
protected R deserializeValue(String resultType, String json) {
return serialization.deserialize(json, resultType);
}
private boolean isSuccessStatusCode(Response response) {
int statusCode = response.getStatusCode();
return (statusCode >= 200 && statusCode < 300) || statusCode == 304;
}
private R getDeserializedResponse(RestAction action, Response response) throws ActionException {
String resultType = (String) metadataProvider.getValue(action, MetadataType.RESPONSE_TYPE);
if (!isNullOrEmpty(resultType) && canDeserialize(resultType)) {
try {
String json = response.getText();
return deserializeValue(resultType, json);
} catch (JsonMappingException e) {
throw new ActionException("Unable to deserialize response. An unexpected error occurred.", e);
}
}
throw new ActionException("Unable to deserialize response. No serializer found.");
}
private boolean isNullOrEmpty(String string) {
return string == null || string.isEmpty();
}
}