import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.Map;
import java.util.LinkedHashMap;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class ShortenUrl {

	private static final boolean DEBUG = true;

	public static void main(String[] args) {
		String url = "http://www.henshiyong.com/tools/sina-shorten-url.php";
		Map<String, String> params = new LinkedHashMap<String, String>();
		params.put("url", "http://www.google.com");
		params.put("submit", "转换");

		String data = null;

		try {
			data = postUrl(url, params);
			if (DEBUG) {
				System.out.println(data);
			}
		} catch (IOException ex) {
		}

		if (data != null) {
			String shortUrl = getShortenUrl(data);
			if (DEBUG) {
				System.out.println(shortUrl);
			}
		}
	}

	public static String getShortenUrl(String content) {
		String url = null;
		List<String> resultList = getContext(content);

		for (Iterator<String> iterator = resultList.iterator(); iterator
				.hasNext();) {
			url = iterator.next();
		}

		return url;
	}

	/**
	 * Extract "XXXX" from "<textarea>XXXX</textarea>"
	 * 
	 * @param html
	 * @return
	 */
	public static List<String> getContext(String html) {
		List<String> resultList = new ArrayList<String>();
		Pattern p = Pattern.compile("<textarea>(.*)</textarea>");
		Matcher m = p.matcher(html);
		while (m.find()) {
			resultList.add(m.group(1));
		}
		return resultList;
	}

	public static class HttpException extends RuntimeException {

		private int errorCode;
		private String errorData;

		public HttpException(int errorCode, String errorData) {
			super("HTTP Code " + errorCode + " : " + errorData);
			this.errorCode = errorCode;
			this.errorData = errorData;
		}

		public int getErrorCode() {
			return errorCode;
		}

		public String getErrorData() {
			return errorData;
		}

	}

	public static String postUrl(String url, Map<String, String> params)
			throws IOException {
		String data = "";
		for (String key : params.keySet()) {
			data += "&" + URLEncoder.encode(key, "UTF-8") + "="
					+ URLEncoder.encode(params.get(key), "UTF-8");
		}
		data = data.substring(1);
		// System.out.println(data);
		URL aURL = new java.net.URL(url);
		HttpURLConnection aConnection = (java.net.HttpURLConnection) aURL
				.openConnection();
		try {
			aConnection.setDoOutput(true);
			aConnection.setDoInput(true);
			aConnection.setRequestMethod("POST");
			// aConnection.setAllowUserInteraction(false);
			// POST the data
			OutputStreamWriter streamToAuthorize = new java.io.OutputStreamWriter(
					aConnection.getOutputStream());
			streamToAuthorize.write(data);
			streamToAuthorize.flush();
			streamToAuthorize.close();

			// check error
			int errorCode = aConnection.getResponseCode();
			if (errorCode >= 400) {
				InputStream errorStream = aConnection.getErrorStream();
				try {
					String errorData = streamToString(errorStream);
					throw new HttpException(errorCode, errorData);
				} finally {
					errorStream.close();
				}
			}

			// Get the Response
			InputStream resultStream = aConnection.getInputStream();
			try {
				String responseData = streamToString(resultStream);
				return responseData;
			} finally {
				resultStream.close();
			}
		} finally {
			aConnection.disconnect();
		}
	}

	private static String streamToString(InputStream resultStream)
			throws IOException {
		BufferedReader aReader = new java.io.BufferedReader(
				new java.io.InputStreamReader(resultStream));
		StringBuffer aResponse = new StringBuffer();
		String aLine = aReader.readLine();
		while (aLine != null) {
			aResponse.append(aLine + "\n");
			aLine = aReader.readLine();
		}
		return aResponse.toString();

	}
}