/*
*
* Copyright (c) 2016 Amazon.com, Inc. or its affiliates. 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.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file 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.amazonaws.http;
import com.amazonaws.AmazonWebServiceResponse;
import com.amazonaws.ResponseMetadata;
import com.amazonaws.annotation.SdkInternalApi;
import com.amazonaws.internal.CRC32MismatchException;
import com.amazonaws.transform.JsonUnmarshallerContext;
import com.amazonaws.transform.JsonUnmarshallerContext.UnmarshallerType;
import com.amazonaws.transform.JsonUnmarshallerContextImpl;
import com.amazonaws.transform.Unmarshaller;
import com.amazonaws.transform.VoidJsonUnmarshaller;
import com.amazonaws.util.IOUtils;
import com.amazonaws.util.ValidationUtils;
import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonParser;
import java.io.IOException;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Default implementation of HttpResponseHandler that handles a successful response from an AWS
* service and unmarshalls the result using a JSON unmarshaller.
*
* @param <T> Indicates the type being unmarshalled by this response handler.
*/
@SdkInternalApi
public class JsonResponseHandler<T> implements HttpResponseHandler<AmazonWebServiceResponse<T>> {
/**
* The JSON unmarshaller to use when handling the response
*/
private Unmarshaller<T, JsonUnmarshallerContext> responseUnmarshaller;
/**
* Shared logger for profiling information
*/
private static final Log log = LogFactory.getLog("com.amazonaws.request");
private final JsonFactory jsonFactory;
private final boolean needsConnectionLeftOpen;
private final boolean isPayloadJson;
private final Map<Class<?>, Unmarshaller<?, JsonUnmarshallerContext>> simpleTypeUnmarshallers;
private final Map<UnmarshallerType, Unmarshaller<?, JsonUnmarshallerContext>> customTypeMarshallers;
/**
* Constructs a new response handler that will use the specified JSON unmarshaller to unmarshall
* the service response and uses the specified response element path to find the root of the
* business data in the service's response.
* @param responseUnmarshaller The JSON unmarshaller to use on the response.
* @param simpleTypeUnmarshallers List of unmarshallers to be used for scalar types.
* @param customTypeMarshallers List of custom unmarshallers to be used for special types.
* @param jsonFactory the json factory to be used for parsing the response.
*/
public JsonResponseHandler(Unmarshaller<T, JsonUnmarshallerContext> responseUnmarshaller,
Map<Class<?>, Unmarshaller<?, JsonUnmarshallerContext>> simpleTypeUnmarshallers,
Map<UnmarshallerType, Unmarshaller<?, JsonUnmarshallerContext>> customTypeMarshallers,
JsonFactory jsonFactory, boolean needsConnectionLeftOpen,
boolean isPayloadJson) {
/*
* Even if the invoked operation just returns null, we still need an
* unmarshaller to run so we can pull out response metadata.
*
* We might want to pass this in through the client class so that we
* don't have to do this check here.
*/
this.responseUnmarshaller =
responseUnmarshaller != null ? responseUnmarshaller : new VoidJsonUnmarshaller<T>();
this.needsConnectionLeftOpen = needsConnectionLeftOpen;
this.isPayloadJson = isPayloadJson;
this.simpleTypeUnmarshallers = ValidationUtils.assertNotNull(simpleTypeUnmarshallers, "simple type unmarshallers");
this.customTypeMarshallers = ValidationUtils.assertNotNull(customTypeMarshallers, "custom type marshallers");
this.jsonFactory = ValidationUtils.assertNotNull(jsonFactory, "JSONFactory");
}
/**
* @see HttpResponseHandler#handle(HttpResponse)
*/
public AmazonWebServiceResponse<T> handle(HttpResponse response) throws Exception {
log.trace("Parsing service response JSON");
String CRC32Checksum = response.getHeaders().get("x-amz-crc32");
JsonParser jsonParser = null;
if (shouldParsePayloadAsJson()) {
jsonParser = jsonFactory.createParser(response.getContent());
}
try {
AmazonWebServiceResponse<T> awsResponse = new AmazonWebServiceResponse<T>();
JsonUnmarshallerContext unmarshallerContext = new JsonUnmarshallerContextImpl(
jsonParser, simpleTypeUnmarshallers, customTypeMarshallers, response);
registerAdditionalMetadataExpressions(unmarshallerContext);
T result = responseUnmarshaller.unmarshall(unmarshallerContext);
// Make sure we read all the data to get an accurate CRC32 calculation.
// See https://github.com/aws/aws-sdk-java/issues/1018
if (shouldParsePayloadAsJson() && response.getContent() != null) {
IOUtils.drainInputStream(response.getContent());
}
if (CRC32Checksum != null) {
long serverSideCRC = Long.parseLong(CRC32Checksum);
long clientSideCRC = response.getCRC32Checksum();
if (clientSideCRC != serverSideCRC) {
throw new CRC32MismatchException(
"Client calculated crc32 checksum didn't match that calculated by server side");
}
}
awsResponse.setResult(result);
Map<String, String> metadata = unmarshallerContext.getMetadata();
metadata.put(ResponseMetadata.AWS_REQUEST_ID,
response.getHeaders().get(X_AMZN_REQUEST_ID_HEADER));
awsResponse.setResponseMetadata(new ResponseMetadata(metadata));
log.trace("Done parsing service response");
return awsResponse;
} finally {
if (shouldParsePayloadAsJson()) {
try {
jsonParser.close();
} catch (IOException e) {
log.warn("Error closing json parser", e);
}
}
}
}
/**
* Hook for subclasses to override in order to collect additional metadata from service
* responses.
*
* @param unmarshallerContext
* The unmarshaller context used to configure a service's response
* data.
*/
protected void registerAdditionalMetadataExpressions(
JsonUnmarshallerContext unmarshallerContext) {
}
public boolean needsConnectionLeftOpen() {
return needsConnectionLeftOpen;
}
/**
* @return True if the payload will be parsed as JSON, false otherwise.
*/
private boolean shouldParsePayloadAsJson() {
return !needsConnectionLeftOpen && isPayloadJson;
}
}