com.subgraph.vega.internal.http.requests.HttpRequestEngine.java Source code

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Here is the source code for com.subgraph.vega.internal.http.requests.HttpRequestEngine.java

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/*******************************************************************************
 * Copyright (c) 2011 Subgraph.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Subgraph - initial API and implementation
 ******************************************************************************/
package com.subgraph.vega.internal.http.requests;

import java.io.IOException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.logging.Logger;

import org.apache.http.HttpException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.client.protocol.ClientContext;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.HttpContext;

import com.subgraph.vega.api.html.IHTMLParser;
import com.subgraph.vega.api.http.requests.IHttpRequestBuilder;
import com.subgraph.vega.api.http.requests.IHttpRequestEngine;
import com.subgraph.vega.api.http.requests.IHttpRequestEngineConfig;
import com.subgraph.vega.api.http.requests.IHttpResponse;
import com.subgraph.vega.api.http.requests.IHttpResponseBuilder;
import com.subgraph.vega.api.http.requests.RequestEngineException;

public class HttpRequestEngine implements IHttpRequestEngine {
    public final static String VEGA_SENT_REQUEST = "vega.sent-request";
    /** Key under which a copy of sent request with actual sent headers is stored in HttpContext */
    private final Logger logger = Logger.getLogger("request-engine");
    private final ExecutorService executor;
    private final HttpClient client;
    private final IHttpRequestEngineConfig config;
    private final IHTMLParser htmlParser;
    private final RateLimiter rateLimit;

    HttpRequestEngine(ExecutorService executor, HttpClient client, IHttpRequestEngineConfig config,
            IHTMLParser htmlParser) {
        this.executor = executor;
        this.client = client;
        this.config = config;
        this.htmlParser = htmlParser;
        this.rateLimit = new RateLimiter(config.getRequestsPerMinute());
    }

    @Override
    public IHttpRequestEngineConfig getRequestEngineConfig() {
        return config;
    }

    @Override
    public IHttpRequestBuilder createRequestBuilder() {
        return new HttpRequestBuilder();
    }

    @Override
    public IHttpResponseBuilder createResponseBuilder() {
        return new HttpResponseBuilder();
    }

    @Override
    public IHttpResponse sendRequest(HttpUriRequest request, HttpContext context) throws RequestEngineException {
        final HttpContext requestContext = (context == null) ? (new BasicHttpContext()) : (context);
        requestContext.setAttribute(ClientContext.COOKIE_STORE, config.getCookieStore());
        Future<IHttpResponse> future = executor
                .submit(new RequestTask(client, rateLimit, request, requestContext, config, htmlParser));
        try {
            return future.get();
        } catch (InterruptedException e) {
            logger.info("Request " + request.getURI() + " was interrupted before completion");
        } catch (ExecutionException e) {
            throw translateException(request, e.getCause());
        }
        return null;
    }

    public IHttpResponse sendRequest(HttpUriRequest request) throws RequestEngineException {
        return sendRequest(request, null);
    }

    private RequestEngineException translateException(HttpUriRequest request, Throwable ex) {
        final StringBuilder sb = new StringBuilder();

        if (ex instanceof IOException) {
            sb.append("Network problem");
        } else if (ex instanceof HttpException) {
            sb.append("Protocol problem");
        } else {
            sb.append("Unknown problem");
        }
        sb.append(" while retrieving URI ");
        sb.append(request.getURI().toString());
        sb.append(" [");
        sb.append(ex.getMessage());
        sb.append("]");
        return new RequestEngineException(sb.toString(), ex);
    }
}