/*
* Copyright 2010-2017 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.services.s3.internal;
import com.amazonaws.AmazonServiceException;
import com.amazonaws.http.HttpMethodName;
import com.amazonaws.http.HttpResponse;
import com.amazonaws.http.HttpResponseHandler;
import com.amazonaws.services.s3.Headers;
import com.amazonaws.services.s3.model.AmazonS3Exception;
import com.amazonaws.util.IOUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Map;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import static com.amazonaws.util.StringUtils.UTF8;
/**
* Response handler for S3 error responses. S3 error responses are different
* from other AWS error responses in a few ways. Most error responses will
* contain an XML body, but not all (ex: error responses to HEAD requests will
* not), so this error handler has to account for that. The actual XML error
* response body is slightly different than other services like SimpleDB or EC2
* and some information isn't explicitly represented in the XML error response
* body (ex: error type/fault information) so it has to be inferred from other
* parts of the error response.
*/
public class S3ErrorResponseHandler implements
HttpResponseHandler<AmazonServiceException> {
/** Shared logger for profiling information */
private static final Log log = LogFactory
.getLog(S3ErrorResponseHandler.class);
/** Shared factory for creating XML event readers */
private static final XMLInputFactory xmlInputFactory = XMLInputFactory
.newInstance();
private static enum S3ErrorTags {
Error, Message, Code, RequestId, HostId
};
@Override
public AmazonServiceException handle(HttpResponse httpResponse)
throws XMLStreamException {
final AmazonServiceException exception = createException(httpResponse);
exception.setHttpHeaders(httpResponse.getHeaders());
return exception;
}
private AmazonServiceException createException(HttpResponse httpResponse) throws
XMLStreamException {
final InputStream is = httpResponse.getContent();
String xmlContent = null;
/*
* We don't always get an error response body back from S3. When we send
* a HEAD request, we don't receive a body, so we'll have to just return
* what we can.
*/
if (is == null
|| httpResponse.getRequest().getHttpMethod() == HttpMethodName.HEAD) {
return createExceptionFromHeaders(httpResponse, null);
}
String content = null;
try {
content = IOUtils.toString(is);
} catch (IOException ioe) {
if (log.isDebugEnabled())
log.debug("Failed in parsing the error response : ", ioe);
return createExceptionFromHeaders(httpResponse, null);
}
/*
* XMLInputFactory is not thread safe and hence it is synchronized.
* Reference :
* http://itdoc.hitachi.co.jp/manuals/3020/30203Y2210e/EY220140.HTM
*/
XMLStreamReader reader;
synchronized (xmlInputFactory) {
reader = xmlInputFactory
.createXMLStreamReader(new ByteArrayInputStream(content
.getBytes(UTF8)));
}
try {
/*
* target depth is to determine if the XML Error response from the
* server has any element inside <Error> tag have child tags.
* Parsing such tags is not supported now. target depth is
* incremented for every start tag and decremented after every end
* tag is encountered.
*/
int targetDepth = 0;
final AmazonS3ExceptionBuilder exceptionBuilder = new AmazonS3ExceptionBuilder();
exceptionBuilder.setErrorResponseXml(content);
exceptionBuilder.setStatusCode(httpResponse.getStatusCode());
exceptionBuilder.setCloudFrontId(httpResponse.getHeaders().get(Headers.CLOUD_FRONT_ID));
boolean hasErrorTagVisited = false;
while (reader.hasNext()) {
int event = reader.next();
switch (event) {
case XMLStreamConstants.START_ELEMENT:
targetDepth++;
String tagName = reader.getLocalName();
if (targetDepth == 1
&& !S3ErrorTags.Error.toString().equals(tagName))
return createExceptionFromHeaders(httpResponse,
"Unable to parse error response. Error XML Not in proper format."
+ content);
if (S3ErrorTags.Error.toString().equals(tagName)) {
hasErrorTagVisited = true;
}
continue;
case XMLStreamConstants.CHARACTERS:
xmlContent = reader.getText();
if (xmlContent != null)
xmlContent = xmlContent.trim();
continue;
case XMLStreamConstants.END_ELEMENT:
tagName = reader.getLocalName();
targetDepth--;
if (!(hasErrorTagVisited) || targetDepth > 1) {
return createExceptionFromHeaders(httpResponse,
"Unable to parse error response. Error XML Not in proper format."
+ content);
}
if (S3ErrorTags.Message.toString().equals(tagName)) {
exceptionBuilder.setErrorMessage(xmlContent);
} else if (S3ErrorTags.Code.toString().equals(tagName)) {
exceptionBuilder.setErrorCode(xmlContent);
} else if (S3ErrorTags.RequestId.toString().equals(tagName)) {
exceptionBuilder.setRequestId(xmlContent);
} else if (S3ErrorTags.HostId.toString().equals(tagName)) {
exceptionBuilder.setExtendedRequestId(xmlContent);
} else {
exceptionBuilder.addAdditionalDetail(tagName, xmlContent);
}
continue;
case XMLStreamConstants.END_DOCUMENT:
return exceptionBuilder.build();
}
}
} catch (Exception e) {
if (log.isDebugEnabled())
log.debug("Failed in parsing the error response : " + content,
e);
}
return createExceptionFromHeaders(httpResponse, content);
}
private AmazonS3Exception createExceptionFromHeaders(
HttpResponse errorResponse, String errorResponseXml) {
final Map<String, String> headers = errorResponse.getHeaders();
final int statusCode = errorResponse.getStatusCode();
final AmazonS3ExceptionBuilder exceptionBuilder = new AmazonS3ExceptionBuilder();
exceptionBuilder.setErrorMessage(errorResponse.getStatusText());
exceptionBuilder.setErrorResponseXml(errorResponseXml);
exceptionBuilder.setStatusCode(statusCode);
exceptionBuilder
.setExtendedRequestId(headers.get(Headers.EXTENDED_REQUEST_ID));
exceptionBuilder.setRequestId(headers.get(Headers.REQUEST_ID));
exceptionBuilder.setCloudFrontId(headers.get(Headers.CLOUD_FRONT_ID));
exceptionBuilder
.setErrorCode(statusCode + " " + errorResponse.getStatusText());
exceptionBuilder.addAdditionalDetail(Headers.S3_BUCKET_REGION,
errorResponse.getHeaders().get(Headers.S3_BUCKET_REGION));
return exceptionBuilder.build();
}
/**
* 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.
*
* @see com.amazonaws.http.HttpResponseHandler#needsConnectionLeftOpen()
*/
public boolean needsConnectionLeftOpen() {
return false;
}
}