/*
* @(#)WebUtils.java 11/11/2004
*
* Copyright (c) 2004, 2005 jASEN.org
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the distribution.
*
* 3. The names of the authors may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 4. Any modification or additions to the software must be contributed back
* to the project.
*
* 5. Any investigation or reverse engineering of source code or binary to
* enable emails to bypass the filters, and hence inflict spam and or viruses
* onto users who use or do not use jASEN could subject the perpetrator to
* criminal and or civil liability.
*
* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JASEN.ORG,
* OR ANY CONTRIBUTORS TO THIS SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
package org.jasen.util;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.MalformedURLException;
import java.net.URL;
import org.jasen.io.NonBlockingStreamReader;
import org.jasen.io.StreamReaderListener;
/**
* <P>
* General WWW and net utility methods.
* </P>
* @author Jason Polites
*/
public class WebUtils
{
public static final String URL_REGEX = "";
/**
* Returns true iff the text passed represents a url.
* <p>
* A url may take many forms:
* <br/><br/>
* For example:
* <ul>
* <li/>www.google.com
* <li/>http://www.google.com
* <li/>google.com
* <li/>toolbar.google.com
* <li/>a.b.c.d.e.f.g.google.com
* <li/>etc...
* </ul>
* </p>
* <p>
* Unfortunately there doesn't seem to be an "elegant" way to determine<br/>
* definatively if an unknown String is in fact a URL. We are just going<br/>
* to use the java.net.URL class and assume a MalformedURLException implies<br/>
* that the string is not a url.
* </p>
* @param text
* @return True if the text is a valid URL, false otherwise
*/
public static boolean isUrl(String text) {
try
{
URL u = new URL(text);
return true;
}
catch (MalformedURLException e)
{
return false;
}
}
/**
* Attempts to download the file given by the URL and saves it to the output stream provided
* <br/>
* NOTE: The given output stream will NOT be closed within this method
* @param url The fully qualified url path to the remote resource
* @param out The output stream to which the data read will be written
* @param bufferSize The buffer size to use for reading bytes
* @param timeout The timeout (in milliseconds) to wait for a response from the remote server
* @throws IOException If an error occurred during transit
*/
public static void get(URL url, OutputStream out, int bufferSize, long timeout) throws IOException {
get(url, out, bufferSize, timeout, null);
}
/**
* Attempts to download the file given by the URL and saves it to the output stream provided
* <br/>
* NOTE: The given output stream will NOT be closed within this method
* @param url The fully qualified url path to the remote resource
* @param out The output stream to which the data read will be written
* @param bufferSize The buffer size to use for reading bytes
* @param timeout The timeout (in milliseconds) to wait for a response from the remote server
* @param listener A listener which will report when bytes have been written to the output stream
* @throws IOException If an error occurred during transit
*/
public static void get(URL url, OutputStream out, int bufferSize, long timeout, StreamReaderListener listener) throws IOException {
InputStream in = null;
NonBlockingStreamReader reader = null;
try {
in = url.openConnection().getInputStream();
reader = new NonBlockingStreamReader(listener);
reader.read(in, out, bufferSize, timeout, null);
}
finally {
if(in != null) {
try {
in.close();
}
catch (IOException ignore) {}
}
}
}
}