tds.itemscoringengine.web.server.ItemScoringEngineHttpWebHelper.java Source code

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Here is the source code for tds.itemscoringengine.web.server.ItemScoringEngineHttpWebHelper.java

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/*******************************************************************************
 * Educational Online Test Delivery System 
 * Copyright (c) 2014 American Institutes for Research
 *   
 * Distributed under the AIR Open Source License, Version 1.0 
 * See accompanying file AIR-License-1_0.txt or at
 * http://www.smarterapp.org/documents/American_Institutes_for_Research_Open_Source_Software_License.pdf
 ******************************************************************************/
package tds.itemscoringengine.web.server;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URISyntaxException;
import java.net.URL;

import javax.annotation.PreDestroy;
import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;

import org.apache.commons.io.output.NullOutputStream;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ByteArrayEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.HttpContext;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import tds.itemscoringengine.ItemScoreResponse;

// TODO Shiva: We right now have copied over HttpWebHelper and
// changed it to just accept ItemScoreResponse. We need to reconcile with what
// is there in
// shared-web. One reason why I decided not to move the following code to
// shared-web is because of the use
// of the possibly "access restricted" class as commented in
// ItemScoreResponse.writeXml().
public class ItemScoringEngineHttpWebHelper {
    private static final Logger _logger = LoggerFactory.getLogger(ItemScoringEngineHttpWebHelper.class);

    private final CloseableHttpClient _client;

    private ThreadLocal<HttpContext> _contextPool = new ThreadLocal<HttpContext>() {
        @Override
        protected HttpContext initialValue() {
            return new BasicHttpContext();
        }
    };

    public ItemScoringEngineHttpWebHelper() {
        PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();
        _client = HttpClientBuilder.create().setConnectionManager(connectionManager).build();
    }

    @PreDestroy
    public void cleanUp() {
        // We hope that, by making the variable inaccessible, we are doing enough to
        // let the GC figure out that it should go away.
        _contextPool = null;

        // Close the client and release its resources
        try {
            _client.close();
        } catch (IOException e) {
            _logger.error("Error closing HTTP client connection pool", e);
        }
    }

    public void sendXml(String url, ItemScoreResponse inputData) {
        sendXml(url, inputData, new NullOutputStream());
    }

    public void sendXml(String url, ItemScoreResponse inputData, OutputStream outputData) {
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        HttpPost post = new HttpPost(url);
        post.setHeader("Content-Type", "text/xml");
        HttpResponse response = null;
        try {
            inputData.writeXML(out);
            ByteArrayEntity entity = new ByteArrayEntity(out.toByteArray());
            post.setEntity(entity);
            response = _client.execute(post, _contextPool.get());
        } catch (IOException | XMLStreamException e) {
            try {
                outputData.write(String.format("HTTP client through exception: %s", e.getMessage()).getBytes());
            } catch (IOException e1) {
                // Our IOExceptioin through an IOException--bad news!!!
                _logger.error("Output stream encountered an error while attempting to process an error message",
                        e1);
                _logger.error(String.format("Original drror message was \"\"", e.getMessage()));
            }
        }
        if (response != null) {
            HttpEntity responseEntity = response.getEntity();
            if (responseEntity != null) {
                String responseString = "";
                try {
                    responseString = EntityUtils.toString(responseEntity);
                    outputData.write(responseString.getBytes());
                } catch (IOException e) {
                    // Our IOExceptioin through an IOException--bad news!!!
                    _logger.error("Output stream encountered an error while attempting to process a reply", e);
                    _logger.error(String.format("Original reply content was \"\"", responseString));
                }
                EntityUtils.consumeQuietly(responseEntity);
            }
        }
    }
}