com.survivingwithandroid.tutorial.asynclistview.MainActivity.java Source code

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Here is the source code for com.survivingwithandroid.tutorial.asynclistview.MainActivity.java

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/*
 * Copyright (C) 2013 Surviving with Android (http://www.survivingwithandroid.com)
 *
 * 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.
 */

package com.survivingwithandroid.tutorial.asynclistview;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.app.ProgressDialog;

import android.widget.ListView;

public class MainActivity extends Activity {
    private SimpleAdapter adpt;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        adpt = new SimpleAdapter(new ArrayList<Contact>(), this);
        ListView lView = (ListView) findViewById(R.id.listview);

        lView.setAdapter(adpt);

        // Exec async load task
        (new AsyncListViewLoader()).execute("http://10.0.2.2:8080/JSONServer/rest/ContactWS/get");
    }

    private class AsyncListViewLoader extends AsyncTask<String, Void, List<Contact>> {
        private final ProgressDialog dialog = new ProgressDialog(MainActivity.this);

        @Override
        protected void onPostExecute(List<Contact> result) {
            super.onPostExecute(result);
            dialog.dismiss();
            adpt.setItemList(result);
            adpt.notifyDataSetChanged();
        }

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            dialog.setMessage("Downloading contacts...");
            dialog.show();
        }

        @Override
        protected List<Contact> doInBackground(String... params) {
            List<Contact> result = new ArrayList<Contact>();

            try {
                URL u = new URL(params[0]);

                HttpURLConnection conn = (HttpURLConnection) u.openConnection();
                conn.setRequestMethod("GET");

                conn.connect();
                InputStream is = conn.getInputStream();

                // Read the stream
                byte[] b = new byte[1024];
                ByteArrayOutputStream baos = new ByteArrayOutputStream();

                while (is.read(b) != -1)
                    baos.write(b);

                String JSONResp = new String(baos.toByteArray());

                JSONArray arr = new JSONArray(JSONResp);
                for (int i = 0; i < arr.length(); i++) {
                    result.add(convertContact(arr.getJSONObject(i)));
                }

                return result;
            } catch (Throwable t) {
                t.printStackTrace();
            }
            return null;
        }

        private Contact convertContact(JSONObject obj) throws JSONException {
            String name = obj.getString("name");
            String surname = obj.getString("surname");
            String email = obj.getString("email");
            String phoneNum = obj.getString("phoneNum");

            return new Contact(name, surname, email, phoneNum);
        }

    }

}