/*
* Copyright 2011-2014 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 java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.List;
import java.util.Map.Entry;
import com.amazonaws.AmazonClientException;
import com.amazonaws.AmazonServiceException;
import com.amazonaws.AmazonServiceException.ErrorType;
import com.amazonaws.transform.JsonErrorUnmarshaller;
import com.amazonaws.util.json.JSONObject;
public class JsonErrorResponseHandler implements HttpResponseHandler<AmazonServiceException> {
/**
* Services using AWS JSON 1.1 protocol with HTTP binding send the error
* type information in the response headers, instead of the content.
*/
private static final String X_AMZN_ERROR_TYPE = "x-amzn-ErrorType";
/**
* The list of error response unmarshallers to try to apply to error
* responses.
*/
private List<? extends JsonErrorUnmarshaller> unmarshallerList;
public JsonErrorResponseHandler(List<? extends JsonErrorUnmarshaller> exceptionUnmarshallers) {
this.unmarshallerList = exceptionUnmarshallers;
}
public AmazonServiceException handle(HttpResponse response) throws Exception {
String streamContents = readStreamContents(response.getContent());
JSONObject jsonErrorMessage;
try {
String s = streamContents;
if (s.length() == 0 || s.trim().length() == 0) s = "{}";
jsonErrorMessage = new JSONObject(s);
} catch (Exception e) {
throw new AmazonClientException("Unable to parse error response: '" + streamContents + "'", e);
}
String errorTypeFromHeader = parseErrorTypeFromHeader(response);
AmazonServiceException ase = runErrorUnmarshallers(response, jsonErrorMessage, errorTypeFromHeader);
if (ase == null) return null;
ase.setServiceName(response.getRequest().getServiceName());
ase.setStatusCode(response.getStatusCode());
if (response.getStatusCode() < 500) {
ase.setErrorType(ErrorType.Client);
} else {
ase.setErrorType(ErrorType.Service);
}
for (Entry<String, String> headerEntry : response.getHeaders().entrySet()) {
if (headerEntry.getKey().equalsIgnoreCase("X-Amzn-RequestId")) {
ase.setRequestId(headerEntry.getValue());
}
}
return ase;
}
private AmazonServiceException runErrorUnmarshallers(HttpResponse errorResponse, JSONObject json, String errorTypeFromHeader) throws Exception {
/*
* We need to select which exception unmarshaller is the correct one to
* use from all the possible exceptions this operation can throw.
* Currently we rely on JsonErrorUnmarshaller.match(...) method which
* checks for the error type parsed either from response headers or the
* content.
*/
for (JsonErrorUnmarshaller unmarshaller : unmarshallerList) {
if (unmarshaller.match(errorTypeFromHeader, json)) {
AmazonServiceException ase = unmarshaller.unmarshall(json);
ase.setStatusCode(errorResponse.getStatusCode());
return ase;
}
}
return null;
}
public boolean needsConnectionLeftOpen() {
return false;
}
private String readStreamContents(final InputStream stream) {
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(stream));
StringBuilder sb = new StringBuilder();
while (true) {
String line = reader.readLine();
if (line == null) break;
sb.append(line);
}
return sb.toString();
} catch (Exception e) {
try {stream.close();} catch (Exception ex) {}
throw new AmazonClientException("Unable to read error response: " + e.getMessage(), e);
}
}
/**
* Attempt to parse the error type from the response headers.
* Returns null if such information is not available in the header.
*/
private String parseErrorTypeFromHeader(HttpResponse response) {
String headerValue = response.getHeaders().get(X_AMZN_ERROR_TYPE);
if (headerValue != null) {
int separator = headerValue.indexOf(':');
if (separator != -1) {
headerValue = headerValue.substring(0, separator);
}
}
return headerValue;
}
}