com.nesscomputing.tinyhttp.HttpFetcher.java Source code

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Here is the source code for com.nesscomputing.tinyhttp.HttpFetcher.java

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/**
 * Copyright (C) 2012 Ness Computing, 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.
 */
package com.nesscomputing.tinyhttp;

import java.io.Closeable;
import java.io.IOException;
import java.net.URI;
import java.security.GeneralSecurityException;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;

import com.google.common.base.Throwables;
import com.google.common.io.Closeables;

import com.nesscomputing.tinyhttp.ssl.HttpsTrustManagerFactory;
import com.nesscomputing.tinyhttp.ssl.SSLConfig;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.client.params.ClientPNames;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.conn.scheme.PlainSocketFactory;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.client.DefaultHttpRequestRetryHandler;
import org.apache.http.impl.conn.SingleClientConnManager;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpParams;
import org.apache.http.protocol.BasicHttpContext;
import org.apache.http.protocol.HttpContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public final class HttpFetcher implements Closeable {
    private static final Logger LOG = LoggerFactory.getLogger(HttpFetcher.class);

    private final HttpParams params = new BasicHttpParams();
    private final SchemeRegistry registry = new SchemeRegistry();
    private final ClientConnectionManager connectionManager;

    private static final Scheme HTTP_SCHEME = new Scheme("http", 80, PlainSocketFactory.getSocketFactory());

    public HttpFetcher() {
        this(null);
    }

    public HttpFetcher(final SSLConfig sslConfig) {
        params.setBooleanParameter(ClientPNames.HANDLE_REDIRECTS, true);
        registry.register(HTTP_SCHEME);

        if (sslConfig != null && sslConfig.isSSLEnabled()) {
            try {
                final TrustManager[] trustManagers = new TrustManager[] {
                        HttpsTrustManagerFactory.getTrustManager(sslConfig) };
                final SSLContext sslContext = SSLContext.getInstance("TLS");
                sslContext.init(null, trustManagers, null);
                final SSLSocketFactory sslSocketFactory = new SSLSocketFactory(sslContext,
                        SSLSocketFactory.STRICT_HOSTNAME_VERIFIER);

                registry.register(new Scheme("https", 443, sslSocketFactory));
                LOG.debug("HTTPS enabled.");
            } catch (GeneralSecurityException ce) {
                throw Throwables.propagate(ce);
            } catch (IOException ioe) {
                throw Throwables.propagate(ioe);
            }
        } else {
            LOG.debug("HTTPS disabled.");
        }

        connectionManager = new SingleClientConnManager(registry);

        LOG.debug("HTTP fetcher ready.");
    }

    @Override
    public void close() {
        connectionManager.shutdown();
    }

    public <T> T get(final URI uri, final String login, final String pw, final HttpContentConverter<T> converter)
            throws IOException {
        final HttpRequestBase httpRequest = new HttpGet(uri);
        final DefaultHttpClient httpClient = new DefaultHttpClient(connectionManager, params);
        // Maximum of three retries...
        httpClient.setHttpRequestRetryHandler(new DefaultHttpRequestRetryHandler(3, false));

        if (login != null) {
            httpClient.setCredentialsProvider(new HttpFetcherCredentialsProvider(login, pw));
        }

        final HttpContentResponseHandler<T> responseHandler = new HttpContentResponseHandler<T>(converter);

        try {
            final HttpContext httpContext = new BasicHttpContext();
            final HttpResponse httpResponse = httpClient.execute(httpRequest, httpContext);

            try {
                return responseHandler.handle(httpRequest, httpResponse);
            } finally {
                // Make sure that the content has definitely been consumed. Otherwise,
                // keep-alive does not work.
                final HttpEntity entity = httpResponse.getEntity();
                if (entity != null) {
                    Closeables.closeQuietly(entity.getContent());
                }
            }
        } catch (Exception e) {
            LOG.warn("Aborting Request!", e);

            httpRequest.abort();
            throw Throwables.propagate(e);
        }
    }
}