/*
* Copyright (C) 2010 Google 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.google.greaze.rest.client;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.StringWriter;
import java.lang.reflect.Type;
import java.net.HttpURLConnection;
import com.google.greaze.client.internal.utils.ConnectionPreconditions;
import com.google.greaze.definition.ContentBodySpec;
import com.google.greaze.definition.ErrorReason;
import com.google.greaze.definition.HeaderMap;
import com.google.greaze.definition.HeaderMapSpec;
import com.google.greaze.definition.LogConfig;
import com.google.greaze.definition.WebServiceSystemException;
import com.google.greaze.definition.internal.utils.Streams;
import com.google.greaze.definition.rest.ResourceId;
import com.google.greaze.definition.rest.RestResourceBase;
import com.google.greaze.definition.rest.RestResponseBase;
import com.google.greaze.definition.rest.RestResponseSpec;
import com.google.greaze.webservice.client.ResponseReceiver;
import com.google.gson.Gson;
/**
* Receives a response coming on an {@link HttpURLConnection}.
*
* @author Inderjeet Singh
*/
public class RestResponseBaseReceiver<I extends ResourceId, R extends RestResourceBase<I, R>>
extends ResponseReceiver {
public RestResponseBaseReceiver(Gson gson, RestResponseSpec spec) {
super(gson, spec);
}
private RestResponseSpec getSpec() {
return (RestResponseSpec) spec;
}
@Override
public RestResponseBase<I, R> receive(HttpURLConnection conn) {
try {
handleResponseCode(conn);
HeaderMapSpec paramSpec = getSpec().getHeadersSpec();
Type bodyType = getSpec().getResourceType();
// read response
HeaderMap responseParams = readResponseHeaders(conn, paramSpec);
R responseBody = readResponseBody(conn, bodyType);
return new RestResponseBase<I, R>(getSpec(), responseParams, responseBody);
} catch (IOException e) {
ErrorReason reason = ErrorReason.fromValue(conn, e);
throw new WebServiceSystemException(reason, e);
}
}
// We could reuse the base classes method, readResponseBody. However, that requires that
// a RequestBody.GsonTypeAdapter is registered. We avoid that registration for REST resources
// with this implementation
@SuppressWarnings("unchecked")
private R readResponseBody(
HttpURLConnection conn, Type resourceType) throws IOException {
String connContentType = conn.getContentType();
ConnectionPreconditions.checkArgument(connContentType != null &&
connContentType.contains(ContentBodySpec.JSON_CONTENT_TYPE), conn);
StringWriter writer = new StringWriter();
Streams.copy(new InputStreamReader(conn.getInputStream()), writer, true, true);
String json = writer.getBuffer().toString();
if (LogConfig.INFO) logger.info("Response Body: " + json);
R body = (R) gson.fromJson(json, resourceType);
return body;
}
}