net.xisberto.phonetodesktop.network.URLOptions.java Source code

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Here is the source code for net.xisberto.phonetodesktop.network.URLOptions.java

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/*******************************************************************************
 * Copyright (c) 2013 Humberto Fraga <xisberto@gmail.com>.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/gpl.html
 * 
 * Contributors:
 *     Humberto Fraga <xisberto@gmail.com> - initial API and implementation
 ******************************************************************************/
package net.xisberto.phonetodesktop.network;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import java.nio.charset.Charset;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import net.xisberto.phonetodesktop.Utils;

import org.apache.http.Header;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.impl.client.DefaultHttpClient;

public class URLOptions {
    private static final Pattern TITLE_TAG = Pattern.compile("\\<title>(.*?)\\</title>",
            Pattern.CASE_INSENSITIVE | Pattern.DOTALL),
            CHARSET_HEADER = Pattern.compile("charset=([-_a-zA-Z0-9]+)", Pattern.CASE_INSENSITIVE | Pattern.DOTALL);

    private boolean isCancelled = false;

    protected void cancel() {
        isCancelled = true;
    }

    protected String[] unshorten(String... params) throws IOException {
        String[] result = params.clone();
        for (int i = 0; i < params.length; i++) {
            Utils.log("unshorten " + params[i]);

            URLConnection connection = new URL(params[i]).openConnection();
            connection.connect();
            InputStream instr = connection.getInputStream();
            instr.close();

            if (isCancelled) {
                return result;
            }

            result[i] = connection.getURL().toString();
            Utils.log("got " + result[i]);
        }
        return result;
    }

    protected String[] getTitles(String... params) throws IOException, NullPointerException {
        String[] result = params.clone();
        for (int i = 0; i < params.length; i++) {
            Utils.log("getTitles " + params[i]);

            String title = getPageTitle(params[i]);
            if (title != null) {
                Utils.log("Found title " + title);
                result[i] = title;
            } else {
                result[i] = params[i];
            }

            if (isCancelled) {
                return result;
            }
        }
        return result;
    }

    /**
     * Loads a url and search for a HTML title. <br>
     * Based on the code found at
     * http://www.gotoquiz.com/web-coding/programming/
     * java-programming/how-to-extract-titles-from-web-pages-in-java/
     * 
     * @param url
     *            the url to load
     * @return the HTML title or {@code null} if it's not a HTML page or if no
     *         title was found
     * @throws IOException
     */
    private String getPageTitle(String url) throws IOException, NullPointerException {
        HttpClient client = new DefaultHttpClient();
        HttpUriRequest request = new HttpGet(url);
        HttpResponse response = client.execute(request);

        if (isCancelled) {
            return null;
        }

        // Make sure this URL goes to a HTML page
        String headerValue = "";
        for (Header header : response.getAllHeaders()) {
            Utils.log("header: " + header.getName());
            if (header.getName().equals("Content-Type")) {
                headerValue = header.getValue();
                break;
            }
        }

        Utils.log("value: " + headerValue);
        String contentType = "";
        Charset charset = Charset.forName("ISO-8859-1");
        int sep = headerValue.indexOf(";");
        if (sep != -1) {
            contentType = headerValue.substring(0, sep);
            Matcher matcherCharset = CHARSET_HEADER.matcher(headerValue);
            if (matcherCharset.find()) {
                charset = Charset.forName(matcherCharset.group(1));
            }
        } else {
            contentType = headerValue;
        }

        if (contentType.equals("text/html")) {
            // Now we can search for <title>
            InputStream in = response.getEntity().getContent();
            BufferedReader reader = new BufferedReader(new InputStreamReader(in, charset));
            int n = 0, totalRead = 0;
            char[] buffer = new char[1024];
            StringBuilder content = new StringBuilder();

            while (totalRead < 8192 && (n = reader.read(buffer, 0, buffer.length)) != -1) {
                content.append(buffer);
                totalRead += n;
                Matcher matcher = TITLE_TAG.matcher(content);
                if (matcher.find()) {
                    reader.close();
                    String result = matcher.group(1).replaceAll("[\\s\\<>]+", " ").trim();
                    return result;
                }
                if (isCancelled) {
                    reader.close();
                    return null;
                }
                Utils.log("Will read some more");
            }
        }
        return null;
    }
}