Java URL to InputStream getInputStream(String url, int timeout)

Description

Attempts to obtain an InputStream from the provided url.

License

Open Source License

Parameter

Parameter	Description
url	the url to get an InputStream from
timeout	the amount of time to try to get an InputStream, a value of zero or lower will cause a default value to be used

Return

an from the url if it can be obtained in less time than timeout, otherwise null

Declaration

public static InputStream getInputStream(String url, int timeout) 

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright (c) 2012 - 2013 IBM Corporation and others.
 * 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://w  w  w  .  ja  va  2  s . c o m
 * IBM Corporation - initial API and implementation
 * yyyymmdd bug      Email and other contact information
 * -------- -------- -----------------------------------------------------------
 *     IBM Corporation - Initial API and implementation
 *******************************************************************************/

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;

public class Main {
    private static final int DEFAULT_TIMEOUT = 2500;

    /**
     * Attempts to obtain an {@link InputStream} from the provided url. If one
     * cannot be opened before <code>timeout</code>, the result is null.
     * 
     * @param url
     *            the url to get an InputStream from
     * @param timeout
     *            the amount of time to try to get an InputStream, a value of
     *            zero or lower will cause a default value to be used
     * @return an {@link InputStream} from the <code>url</code> if it can be
     *         obtained in less time than <code>timeout</code>, otherwise
     *         <code>null</code>
     * 
     */
    public static InputStream getInputStream(String url, int timeout) {
        final InputStream[] result = new InputStream[1];
        try {
            final URLConnection connection = new URL(url).openConnection();
            final Thread streamOpener = new Thread() {
                public void run() {
                    try {
                        result[0] = connection.getInputStream();
                    } catch (IOException e) {
                    } finally {
                        /*
                         * Main thread moved on, cleanup.
                         */
                        if (isInterrupted() && result[0] != null) {
                            try {
                                result[0].close();
                            } catch (IOException e) {
                            }
                        }
                    }
                }
            };
            streamOpener.start();
            try {
                streamOpener.join(timeout < 1 ? DEFAULT_TIMEOUT : timeout);
                /*
                 * allow some time to open the inputstream
                 */
                if (streamOpener.isAlive())
                    streamOpener.interrupt();
            } catch (InterruptedException e) {
                if (result[0] == null) {
                    result[0] = connection.getInputStream();//bug407211
                }
                Thread.currentThread().interrupt();
            }
        } catch (IOException e) {
        }
        return result[0];
    }
}

Related

1. getInputStream(URL sourceURL)
2. getInputStream(URL url)
3. getInputStream(URL url)
4. getInputStream(URL url)