com.amazonaws.http.StaxRxNettyResponseHandler Maven / Gradle / Ivy

Go to download
/*
 * Copyright 2010-2015 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.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.Map;
import java.util.HashMap;

import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;

import rx.Observable;
import rx.functions.*;
import io.netty.buffer.ByteBuf;
import iep.io.reactivex.netty.protocol.http.client.HttpClientResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import com.amazonaws.AmazonWebServiceResponse;
import com.amazonaws.ResponseMetadata;
import com.amazonaws.transform.StaxUnmarshallerContext;
import com.amazonaws.transform.Unmarshaller;
import com.amazonaws.transform.VoidStaxUnmarshaller;
import com.amazonaws.util.RxSchedulers;

/**
 * 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 StaxRxNettyResponseHandler implements RxNettyResponseHandler> {

    /** The StAX unmarshaller to use when handling the response */
    private Unmarshaller responseUnmarshaller;

    /** Shared logger for profiling information */
    private static final Log log = LogFactory.getLog("com.amazonaws.request");

    /** Shared factory for creating XML event readers */
    private static final XMLInputFactory xmlInputFactory = XMLInputFactory.newInstance();


    /**
     * 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 StaxRxNettyResponseHandler(Unmarshaller responseUnmarshaller) {
        this.responseUnmarshaller = responseUnmarshaller;
        if (this.responseUnmarshaller == null) {
            this.responseUnmarshaller = new VoidStaxUnmarshaller();
        }
    }

    @Override
    public AmazonWebServiceResponse handle(HttpResponse r) {
      throw new UnsupportedOperationException("apache client not suppported");
    }

    @Override
    public Observable> handle(HttpClientResponse response) throws Exception {
      return response.getContent().reduce(
        new ByteArrayOutputStream(),
        new Func2() {
          @Override
          public ByteArrayOutputStream call(ByteArrayOutputStream out, ByteBuf bb) {
            try {
              bb.readBytes(out, bb.readableBytes());
              return out;
            }
            catch (java.io.IOException e) {
              throw new RuntimeException(e);
            }
          }
        }
      )
      .observeOn(RxSchedulers.computation())
      .flatMap(out -> {
        byte[] bytes = out.toByteArray();
        if (bytes.length == 0) bytes = "".getBytes();
        ByteArrayInputStream in = new ByteArrayInputStream(bytes);
        XMLEventReader reader = null;
        try {
          reader = xmlInputFactory.createXMLEventReader(in);
        }
        catch (XMLStreamException e) {
          throw new RuntimeException(e);
        }
        try {
          Map responseHeaders = new HashMap();
          for (String k : response.getHeaders().names()) {
            // TODO: comma seperated?
            responseHeaders.put(k, response.getHeaders().get(k));
          }
          AmazonWebServiceResponse awsResponse = new AmazonWebServiceResponse();
          StaxUnmarshallerContext unmarshallerContext = new StaxUnmarshallerContext(reader, responseHeaders);
          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();
          if (responseHeaders != null) {
            if (responseHeaders.get("x-amzn-RequestId") != null) {
              metadata.put(ResponseMetadata.AWS_REQUEST_ID, responseHeaders.get("x-amzn-RequestId"));
            }
          }
          awsResponse.setResponseMetadata(new ResponseMetadata(metadata));

          return Observable.just(awsResponse);
        }
        catch (Exception e) {
          throw new RuntimeException(e);
        }
        finally {
          try {
            reader.close();
          } catch (XMLStreamException e) {
            log.warn("Error closing xml parser", e);
          }
        }
      });
    }

    /**
     * Hook for subclasses to override in order to collect additional metadata
     * from service responses.
     *
     * @param unmarshallerContext
     *            The unmarshaller context used to process 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.
     *
     * @see com.amazonaws.http.HttpResponseHandler#needsConnectionLeftOpen()
     */
    public boolean needsConnectionLeftOpen() {
        return false;
    }

}