Java tutorial
/* * aTunes * Copyright (C) Alex Aranda, Sylvain Gaudard and contributors * * See http://www.atunes.org/wiki/index.php?title=Contributing for information about contributors * * http://www.atunes.org * http://sourceforge.net/projects/atunes * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ package net.sourceforge.atunes.kernel.modules.network; import java.awt.Image; import java.awt.color.CMMException; import java.io.BufferedInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStreamWriter; import java.io.UnsupportedEncodingException; import java.net.Authenticator; import java.net.URL; import java.net.URLConnection; import java.net.URLEncoder; import java.net.UnknownHostException; import java.util.ArrayList; import java.util.List; import java.util.Map; import javax.imageio.ImageIO; import net.sourceforge.atunes.Constants; import net.sourceforge.atunes.kernel.AbstractHandler; import net.sourceforge.atunes.model.INetworkHandler; import net.sourceforge.atunes.model.IProxyBean; import net.sourceforge.atunes.model.IStateCore; import net.sourceforge.atunes.utils.ClosingUtils; import net.sourceforge.atunes.utils.Logger; import net.sourceforge.atunes.utils.StringUtils; import org.apache.commons.io.IOUtils; import de.umass.lastfm.Caller; /** * Responsible of handling network connections * * @author alex * */ /** * @author alex * */ public class NetworkHandler extends AbstractHandler implements INetworkHandler { private IStateCore stateCore; private int connectTimeoutInSeconds; private int readTimeoutInSeconds; /** * @param connectTimeoutInSeconds */ public void setConnectTimeoutInSeconds(final int connectTimeoutInSeconds) { this.connectTimeoutInSeconds = connectTimeoutInSeconds; } /** * @param readTimeoutInSeconds */ public void setReadTimeoutInSeconds(final int readTimeoutInSeconds) { this.readTimeoutInSeconds = readTimeoutInSeconds; } /** * @param stateCore */ public void setStateCore(final IStateCore stateCore) { this.stateCore = stateCore; } @Override protected void initHandler() { updateProxy(stateCore.getProxy()); } /** * @param proxy */ @Override public void updateProxy(final IProxyBean proxy) { try { ExtendedProxy extendedProxy = ExtendedProxy.getProxy(proxy); initProxy(extendedProxy); // Necessary for last.fm Caller.getInstance().setProxy(extendedProxy); } catch (UnknownHostException e) { Logger.error(e); } catch (IOException e) { Logger.error(e); } } /** * Initializes proxy authenticator * * @param proxy */ private void initProxy(final ExtendedProxy proxy) { if (proxy != null) { Authenticator.setDefault(new ProxyAuthenticator(proxy)); } else { Authenticator.setDefault(null); } } /** * Encodes a string in a format suitable to send a http request. * * @param s * The String that should be encoded * * @return A suitable encoded String */ @Override public String encodeString(final String s) { try { return URLEncoder.encode(s, "UTF-8"); } catch (UnsupportedEncodingException e) { return s; } } /** * Returns a HttpURLConnection specified by a given URL * * @param urlString * A URL as String * * @return A HttpURLConnection * * @throws IOException * If an IO exception occurs */ @Override public URLConnection getConnection(final String urlString) throws IOException { Logger.debug("Opening Connection With: ", urlString); URL url = new URL(urlString); URLConnection connection; ExtendedProxy proxy = ExtendedProxy.getProxy(stateCore.getProxy()); if (proxy == null) { connection = url.openConnection(); } else { connection = url.openConnection(proxy); } connection.setRequestProperty("User-agent", Constants.APP_NAME); connection.setConnectTimeout(connectTimeoutInSeconds * 1000); connection.setReadTimeout(readTimeoutInSeconds * 1000); return connection; } /** * Reads a Image from a given URLConnection. * * @param connection * A URLConnection * * @return The Image that was read from the URLConnection * * @throws IOException * If an IO exception occurs */ @Override public Image getImage(final URLConnection connection) throws IOException { InputStream input = null; try { input = connection.getInputStream(); return ImageIO.read(input); } catch (CMMException e) { // Exception reading image format Logger.error(e.getMessage()); return null; } finally { ClosingUtils.close(input); } } /** * Reads a String from a given URLConnection. * * @param connection * A URLConnection * * @return A String read from a given URLConnection * * @throws IOException * If an IO exception occurs */ @Override public String readURL(final URLConnection connection) throws IOException { InputStream input = null; try { input = connection.getInputStream(); return IOUtils.toString(input); } finally { ClosingUtils.close(input); } } @Override public String readURL(final URLConnection connection, final int bytes) throws IOException { BufferedInputStream bis = null; try { InputStream input = connection.getInputStream(); bis = new BufferedInputStream(input); byte[] array = new byte[bytes]; int read = bis.read(array); return read != -1 ? new String(array) : null; } finally { ClosingUtils.close(bis); } } /** * Reads a String from a given URLConnection with a given charset encoding. * * @param connection * A URLConnection * @param charset * A charset as String, e.g. "UTF-8" * * @return A String read from a given URLConnection * * @throws IOException * If an IO exception occurs */ @Override public String readURL(final URLConnection connection, final String charset) throws IOException { InputStream input = null; try { input = connection.getInputStream(); return IOUtils.toString(input, charset); } finally { ClosingUtils.close(input); } } /** * Sends a POST request with given parameters and receives response with * given charset * * @param requestURL * @param params * @param charset * @return * @throws IOException */ @Override public String readURL(final String requestURL, final Map<String, String> params, final String charset) throws IOException { URLConnection connection = getConnection(requestURL); connection.setUseCaches(false); connection.setDoInput(true); if (params != null && params.size() > 0) { connection.setDoOutput(true); OutputStreamWriter writer = new OutputStreamWriter(connection.getOutputStream()); writer.write(formatPOSTParameters(params)); writer.flush(); } InputStream input = null; try { input = connection.getInputStream(); return IOUtils.toString(input, charset); } finally { ClosingUtils.close(input); } } private String formatPOSTParameters(final Map<String, String> parameters) throws UnsupportedEncodingException { List<String> requestParams = new ArrayList<String>(); for (Map.Entry<String, String> parameter : parameters.entrySet()) { requestParams.add(formatPOSTParameter(parameter)); } return org.apache.commons.lang.StringUtils.join(requestParams, '&'); } private String formatPOSTParameter(final Map.Entry<String, String> parameter) throws UnsupportedEncodingException { return StringUtils.getString(URLEncoder.encode(parameter.getKey(), "UTF-8"), "=", URLEncoder.encode(parameter.getValue(), "UTF-8")); } }