org.apache.http.impl.client.FutureRequestExecutionService Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of httpclient Show documentation
Builds the httpclient. Requires the commons logging to be built first and be excluded from any other poms requiring it.
The newest version!
/*
 * ====================================================================
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * .
 *
 */
package org.apache.http.impl.client;

import java.io.Closeable;
import java.io.IOException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.atomic.AtomicBoolean;

import org.apache.http.annotation.Contract;
import org.apache.http.annotation.ThreadingBehavior;
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.concurrent.FutureCallback;
import org.apache.http.protocol.HttpContext;

/**
 * HttpAsyncClientWithFuture wraps calls to execute with a {@link HttpRequestFutureTask}
 * and schedules them using the provided executor service. Scheduled calls may be cancelled.
 */
@Contract(threading = ThreadingBehavior.SAFE)
public class FutureRequestExecutionService implements Closeable {

    private final HttpClient httpclient;
    private final ExecutorService executorService;
    private final FutureRequestExecutionMetrics metrics = new FutureRequestExecutionMetrics();
    private final AtomicBoolean closed = new AtomicBoolean(false);

    /**
     * Create a new FutureRequestExecutionService.
     *
     * @param httpclient
     *            you should tune your httpclient instance to match your needs. You should
     *            align the max number of connections in the pool and the number of threads
     *            in the executor; it doesn't make sense to have more threads than connections
     *            and if you have less connections than threads, the threads will just end up
     *            blocking on getting a connection from the pool.
     * @param executorService
     *            any executorService will do here. E.g.
     *            {@link java.util.concurrent.Executors#newFixedThreadPool(int)}
     */
    public FutureRequestExecutionService(
            final HttpClient httpclient,
            final ExecutorService executorService) {
        this.httpclient = httpclient;
        this.executorService = executorService;
    }

    /**
     * Schedule a request for execution.
     *
     * @param 
     *
     * @param request
     *            request to execute
     * @param responseHandler
     *            handler that will process the response.
     * @return HttpAsyncClientFutureTask for the scheduled request.
     */
    public  HttpRequestFutureTask execute(
            final HttpUriRequest request,
            final HttpContext context,
            final ResponseHandler responseHandler) {
        return execute(request, context, responseHandler, null);
    }

    /**
     * Schedule a request for execution.
     *
     * @param 
     *
     * @param request
     *            request to execute
     * @param context
     *            optional context; use null if not needed.
     * @param responseHandler
     *            handler that will process the response.
     * @param callback
     *            callback handler that will be called when the request is scheduled,
     *            started, completed, failed, or cancelled.
     * @return HttpAsyncClientFutureTask for the scheduled request.
     */
    public  HttpRequestFutureTask execute(
            final HttpUriRequest request,
            final HttpContext context,
            final ResponseHandler responseHandler,
            final FutureCallback callback) {
        if(closed.get()) {
            throw new IllegalStateException("Close has been called on this httpclient instance.");
        }
        metrics.getScheduledConnections().incrementAndGet();
        final HttpRequestTaskCallable callable = new HttpRequestTaskCallable(
            httpclient, request, context, responseHandler, callback, metrics);
        final HttpRequestFutureTask httpRequestFutureTask = new HttpRequestFutureTask(
            request, callable);
        executorService.execute(httpRequestFutureTask);

        return httpRequestFutureTask;
    }

    /**
     * @return metrics gathered for this instance.
     * @see FutureRequestExecutionMetrics
     */
    public FutureRequestExecutionMetrics metrics() {
        return metrics;
    }

    @Override
    public void close() throws IOException {
        closed.set(true);
        executorService.shutdownNow();
        if (httpclient instanceof Closeable) {
            ((Closeable) httpclient).close();
        }
    }
}