실천: 네트워크 프로그래밍

public class HttpUtil {
    public static String sendHttpRequest(String address) {
        HttpURLConnection connection = null;
        try {
            URL url = new URL(address);
            connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");
            connection.setConnectTimeout(8000);
            connection.setReadTimeout(8000);
            connection.setDoInput(true);
            connection.setDoOutput(true);
            InputStream in = connection.getInputStream();
            BufferedReader reader = new BufferedReader(new
            InputStreamReader(in));
            StringBuilder response = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                response.append(line);
            }
            return response.toString();
        } catch (Exception e) {
            e.printStackTrace();
            return e.getMessage();
        } finally {
            if (connection != null) {
                connection.disconnect();
            }
        }
    }
}

String address = "http://www.baidu.com";
String response = HttpUtil.sendHttpRequest(address);

public interface HttpCallbackListener {
    void onFinish(String response);
    void onError(Exception e);
}

public class HttpUtil {
    public static void sendHttpRequest(final String address, final HttpCallbackListener listener) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                HttpURLConnection connection = null;
                try {
                    URL url = new URL(address);
                    connection = (HttpURLConnection) url.openConnection();
                    connection.setRequestMethod("GET");
                    connection.setConnectTimeout(8000);
                    connection.setReadTimeout(8000);
                    connection.setDoInput(true);
                    connection.setDoOutput(true);
                    InputStream in = connection.getInputStream();
                    BufferedReader reader = new BufferedReader(new
                    InputStreamReader(in));
                    StringBuilder response = new StringBuilder();\
                    String line;
                    while ((line = reader.readLine()) != null) {
                        response.append(line);
                    }
                    if (listener != null) {
                        //   onFinish()  
                        listener.onFinish(response.toString());
                    }
                } catch (Exception e) {
                    if (listener != null) {
                        //   onError()  
                        listener.onError(e);
                    }
                } finally {
                    if (connection != null) {
                        connection.disconnect();
                    }
                }
            }
        }).start();
    }
}

HttpUtil.sendHttpRequest(address, new HttpCallbackListener() {
    @Override
    public void onFinish(String response) {
        //                 
    }
    @Override
    public void onError(Exception e) {
        //             
    }
});