/* Copyright 2010 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License 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.
*
* $Id: URLConnectionStrategy.java 526 2010-02-18 23:00:24Z dchung@google.com $
*/
package com.google.dataconnector.client.fetchrequest;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import org.apache.log4j.Logger;
import com.google.dataconnector.client.StrategyException;
import com.google.dataconnector.client.FetchRequestHandler.Strategy;
import com.google.dataconnector.protocol.proto.SdcFrame.FetchReply;
import com.google.dataconnector.protocol.proto.SdcFrame.FetchRequest;
import com.google.protobuf.ByteString;
/**
* Simple strategy of getting all the bytes from a URLConnection and send back
* to the cloud.
*
* @author dchung
*
*/
public class URLConnectionStrategy implements Strategy {
private static Logger LOG = Logger.getLogger(URLConnectionStrategy.class);
public URLConnectionStrategy() {
// Default constructor.
}
/**
* Implements the strategy method of processing the request and filling in the
* reply with results of processing.
*
* @param request The request.
* @param reply The reply to fill in.
*/
@Override
public void process(FetchRequest request, FetchReply.Builder replyBuilder)
throws StrategyException {
try {
// Perform the actual fetch here.
URL resource = new URL(request.getResource());
// Connect to resource.
URLConnection conn = resource.openConnection();
// Copy the result to reply buffer.
ByteArrayOutputStream contents = new ByteArrayOutputStream();
byte[] buffer = new byte[2048];
int bytesRead = 0;
int totalRead = 0;
while ((bytesRead = conn.getInputStream().read(buffer)) > 0) {
contents.write(buffer, 0, bytesRead);
totalRead += bytesRead;
}
LOG.info("Read resource " + resource + ", bytes=" + totalRead);
// finally set the content in the reply, if we have data
if (totalRead > 0) {
replyBuilder.setContents(ByteString.copyFrom(contents.toByteArray()));
}
replyBuilder.setStatus(0);
} catch (MalformedURLException e) {
throw new StrategyException(request.getId() + ": bad url.", e);
} catch (IOException e) {
throw new StrategyException(request.getId() + ": io exception.", e);
}
}
}