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The AWS SDK for Java - Core module holds the classes that are used by the individual service clients to interact with Amazon Web Services. Users need to depend on aws-java-sdk artifact for accessing individual client classes.
/*
* Copyright 2010-2024 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.internal.SdkFilterInputStream;
import com.amazonaws.transform.StaxUnmarshallerContext;
import com.amazonaws.transform.Unmarshaller;
import com.amazonaws.transform.VoidStaxUnmarshaller;
import com.amazonaws.util.StringUtils;
import com.amazonaws.util.XmlUtils;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Map;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLStreamException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.impl.io.EmptyInputStream;
/**
* Default implementation of HttpResponseHandler that handles a successful
* response from an AWS service and unmarshalls the result using a StAX
* unmarshaller.
*
* @param Indicates the type being unmarshalled by this response handler.
*/
public class StaxResponseHandler implements HttpResponseHandler> {
/**
* The StAX unmarshaller to use when handling the response
*/
private Unmarshaller responseUnmarshaller;
private final boolean needsConnectionLeftOpen;
private final boolean isPayloadXML;
/**
* Shared logger for profiling information
*/
private static final Log log = LogFactory.getLog("com.amazonaws.request");
public StaxResponseHandler(Unmarshaller responseUnmarshaller, boolean needsConnectionLeftOpen, boolean isPayloadXML) {
this.responseUnmarshaller = responseUnmarshaller;
/*
* 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.
*/
if (this.responseUnmarshaller == null) {
this.responseUnmarshaller = new VoidStaxUnmarshaller();
}
this.needsConnectionLeftOpen = needsConnectionLeftOpen;
this.isPayloadXML = isPayloadXML;
}
/**
* Constructs a new response handler that will use the specified StAX
* 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 StAX unmarshaller to use on the response.
*/
public StaxResponseHandler(Unmarshaller responseUnmarshaller) {
this(responseUnmarshaller, false, true);
}
/**
* @see HttpResponseHandler#handle(HttpResponse)
*/
public AmazonWebServiceResponse handle(HttpResponse response) throws Exception {
log.trace("Parsing service response XML");
InputStream content = response.getContent();
/**
* Send an empty ByteArrayInputStream when the http response is not XML.
*/
if (content == null || !shouldParsePayloadAsXml()) {
content = new ByteArrayInputStream(" awsResponse = new AmazonWebServiceResponse();
StaxUnmarshallerContext unmarshallerContext =
new StaxUnmarshallerContext(eventReader, response.getHeaders(), response);
unmarshallerContext.registerMetadataExpression("ResponseMetadata/RequestId", 2, ResponseMetadata.AWS_REQUEST_ID);
unmarshallerContext.registerMetadataExpression("requestId", 2, ResponseMetadata.AWS_REQUEST_ID);
registerAdditionalMetadataExpressions(unmarshallerContext);
T result = responseUnmarshaller.unmarshall(unmarshallerContext);
awsResponse.setResult(result);
Map metadata = unmarshallerContext.getMetadata();
Map responseHeaders = response.getHeaders();
if (responseHeaders != null) {
if (responseHeaders.get(X_AMZN_REQUEST_ID_HEADER) != null) {
metadata.put(ResponseMetadata.AWS_REQUEST_ID,
responseHeaders.get(X_AMZN_REQUEST_ID_HEADER));
}
if (responseHeaders.get(X_AMZN_EXTENDED_REQUEST_ID_HEADER) != null) {
metadata.put(ResponseMetadata.AWS_EXTENDED_REQUEST_ID,
responseHeaders.get(X_AMZN_EXTENDED_REQUEST_ID_HEADER));
}
}
awsResponse.setResponseMetadata(getResponseMetadata(metadata));
log.trace("Done parsing service response");
return awsResponse;
} catch (XMLStreamException e) {
throw handleXmlStreamException(e);
} finally {
try {
eventReader.close();
} catch (XMLStreamException e) {
log.warn("Error closing xml parser", e);
}
}
}
/**
* If the exception was caused by an {@link IOException}, wrap it an another IOE so
* that it will be exposed to the RetryPolicy.
*/
private Exception handleXmlStreamException(XMLStreamException e) throws Exception {
if (e.getNestedException() instanceof IOException) {
return new IOException(e);
}
return e;
}
/**
* Create the default {@link ResponseMetadata}. Subclasses may override this to create a
* subclass of {@link ResponseMetadata}. Currently only SimpleDB does this.
*/
protected ResponseMetadata getResponseMetadata(Map metadata) {
return new ResponseMetadata(metadata);
}
/**
* 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(StaxUnmarshallerContext unmarshallerContext) {
}
/**
* Since this response handler completely consumes all the data from the
* underlying HTTP connection during the handle method, we don't need to
* keep the HTTP connection open in most of the cases.
* However, we need it for payload as InputStream.
*
* @see com.amazonaws.http.HttpResponseHandler#needsConnectionLeftOpen()
*/
public boolean needsConnectionLeftOpen() {
return needsConnectionLeftOpen;
}
/**
* @return True if the payload will be parsed as XML, false otherwise.This false whenever response content is blob type.
*/
private boolean shouldParsePayloadAsXml() {
return !needsConnectionLeftOpen && isPayloadXML;
}
}