edu.vanderbilt.android.vuparking.network.ParkingClient.java Source code

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Here is the source code for edu.vanderbilt.android.vuparking.network.ParkingClient.java

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/*****************************************************************************
 *   Copyright VUparking for CS279 project                                   *
 *   Developed by Xiaowei Li, Yuan Zhuang                                    *
 *   Licensed under the Apache License, Version 2.0 (the "License");         *
 *   you may not use this file except in compliance with the License.        *
 *   You may obtain a copy of the License at                                 *
 *                                                                           *
 *   http://www.apache.org/licenses/LICENSE-2.0                              *
 *                                                                           *
 *   Unless required by applicable law or agreed to in writing, software     *
 *   distributed under the License is distributed on an "AS IS" BASIS,       *
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.*
 *   See the License for the specific language governing permissions and     *
 *   limitations under the License.                                          *
 ****************************************************************************/

// This file is written for contacting server for latest parking information.

package edu.vanderbilt.android.vuparking.network;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.SocketTimeoutException;

import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.json.JSONArray;
import org.json.JSONException;

import edu.vanderbilt.android.vuparking.ParkingDBManager;

import android.content.Context;
import android.widget.Toast;

public class ParkingClient {
    private Context mContext;
    private HttpClient client;

    public ParkingClient(Context context) {
        mContext = context;
        HttpParams httpParameters = new BasicHttpParams();
        // Set the timeout in milliseconds.
        int timeoutConnection = 3000;
        HttpConnectionParams.setConnectionTimeout(httpParameters, timeoutConnection);
        // Set the default socket timeout (SO_TIMEOUT) 
        int timeoutSocket = 5000;
        HttpConnectionParams.setSoTimeout(httpParameters, timeoutSocket);
        client = new DefaultHttpClient(httpParameters);
    }

    // Get parking lots information from the server
    public void getResponse() {
        //String getUrl = "http://10.0.2.2:8888/vuparkingservice";
        String getUrl = "http://vuparking.appspot.com/vuparkingservice";
        HttpGet request = new HttpGet(getUrl);
        try {
            String result;
            HttpResponse response = client.execute(request);

            int status = response.getStatusLine().getStatusCode();
            if (status == HttpStatus.SC_OK) {
                result = convertToString(response);
                //Toast.makeText(mContext, result, Toast.LENGTH_SHORT).show();
                JSONArray servResp = new JSONArray(result);

                // Update information in DB
                updateDB(servResp);
            } else {
                result = "Error when getting data from server.";
                Toast.makeText(mContext, result, Toast.LENGTH_SHORT).show();
            }
        } catch (SocketTimeoutException e) {
            Toast.makeText(mContext, "Error:" + e.getMessage(), Toast.LENGTH_SHORT).show();
        } catch (JSONException e) {
            Toast.makeText(mContext, "Error:" + e.getMessage(), Toast.LENGTH_SHORT).show();
        } catch (IOException e) {
            Toast.makeText(mContext, "Error:" + e.getMessage(), Toast.LENGTH_SHORT).show();
        }
    }

    // Update information in DB
    public void updateDB(JSONArray servResp) {
        ParkingDBManager manager = new ParkingDBManager();
        if (manager.openDB()) {
            manager.updateDB(servResp);
            Toast.makeText(mContext, "Updating finished.", Toast.LENGTH_SHORT).show();
        } else
            Toast.makeText(mContext, "Database open failed!", Toast.LENGTH_SHORT).show();
    }

    // Converting http response to string.
    public String convertToString(HttpResponse response) {
        String text = "";
        try {
            text = convertToString(response.getEntity().getContent());
        } catch (Exception ex) {
        }
        return text;
    }

    // Overloaded helper function for parsing to string.
    public String convertToString(InputStream in) {
        String text = "";
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        StringBuilder sb = new StringBuilder();
        String line = null;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            text = sb.toString();
        } catch (Exception ex) {
        } finally {
            try {
                in.close();
            } catch (Exception ex) {
            }
        }
        return text;
    }
}