Supporting Billions of entities/rows for Mobile – Android Series - Part 8–Writing an Android Client to consume RESTful data from Azure (Microsoft Cloud)

 package com.bruno.cloudclient;import java.io.IOException;import com.bruno.cloudclient.R;import android.app.Activity;import android.app.Dialog;import android.content.Context;import android.content.SharedPreferences;import android.graphics.LightingColorFilter;import android.os.Bundle;import android.view.Gravity;import android.view.KeyEvent;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.AdapterView;import android.widget.ArrayAdapter;import android.widget.Button;import android.widget.EditText;import android.widget.ImageView;import android.widget.ListView;import android.widget.TextView;import android.widget.Toast;import android.widget.AdapterView.OnItemClickListener;public class CloudClientActivity extends Activity {        /** Called when the activity is first created. */    ArrayAdapter<String> adapter = null;  //     String listName;    SharedPreferences settings;    /***************************************************************    *  Purpose      - Startup routine. Configures view and accesses    *                 xml file that is your view. Set the file system    *                 sharing mode.    ****************************************************************/    @Override    public void onCreate(Bundle savedInstanceState)     {        try         {            super.onCreate(savedInstanceState);            setContentView(R.layout.main);            // Set file sharing mode to private            settings = getPreferences(Context.MODE_PRIVATE);            listName = settings.getString("listName", "Bruno");            // Get some data. Create an adapter and attach to our listview             // control.            final Data data = new Data();            // This is a key call. It retrieves the dat from the web service.            // The data is in JSON originally, then converted to simple strings.            adapter = new ArrayAdapter<String>(this, R.layout.list_item,                    R.id.listItem, data.getItems(listName));            // Attach the data to the ListView            final ListView myList = (ListView) findViewById(R.id.list);            myList.setAdapter(adapter);            // Create an "Add" button. This button will allow users to            // add data stored in web service.            Button btnAdd = (Button) findViewById(R.id.btnAdd);            // Manage button color for a black screen            btnAdd.getBackground().setColorFilter(                    new LightingColorFilter(0xFFFFFFFF, 0xFFAA0000));            // Add a textbox the user can use to enter new data to be added            // to the web service.            final EditText txtItem = (EditText) findViewById(R.id.txtItem);            // Setup the button listener            btnAdd.setOnClickListener(new Button.OnClickListener() {                public void onClick(View v) {                    settings = getPreferences(Context.MODE_PRIVATE);                    listName = settings.getString("listName", "Bruno");                    // Passing true to modifyData, which will add a new record                    // in the cloud                    data.modifyItem(listName, txtItem.getText().toString(), true);                    // Clear the textbox                    txtItem.setText("");                    try {                        refresh();                    } catch (IOException e) {                        // TODO Auto-generated catch block                        e.printStackTrace();                    }                }            });            // If you click on a ListItem in the ListBox you will            // pass "false" to modifyItem() which will delete            // a record in the cloud            myList.setOnItemClickListener(new OnItemClickListener()             {                public void onItemClick(AdapterView<?> a, View v, int position,                        long id)                 {                    String s = myList.getItemAtPosition(position).toString();                    settings = getPreferences(Context.MODE_PRIVATE);                    listName = settings.getString("listName", "Bruno");                    data.modifyItem(listName, s, false);                    try                     {                        refresh();  // Refresh the listbox to reflect the deleted entry                    }                     catch (IOException e)                     {                        // TODO Auto-generated catch block                        e.printStackTrace();                    }                    // Notify user that record was just deleted                    makeToast(s);                }            });        }         catch (Exception e)         {            e.printStackTrace();        }    }     /***************************************************************    *  Purpose      - Notify user that we just deleted a record    *                 Pops a little message    ****************************************************************/    public void makeToast(String item)     {        LayoutInflater inflater = getLayoutInflater();        View layout = inflater.inflate(R.layout.toast_layout,                (ViewGroup) findViewById(R.id.toast_layout_root));        ImageView image = (ImageView) layout.findViewById(R.id.image);        image.setImageResource(R.drawable.icon);        TextView text = (TextView) layout.findViewById(R.id.text);        text.setText(item + " deleted.");        Toast toast = new Toast(getApplicationContext());        toast.setGravity(Gravity.CENTER_VERTICAL, 0, 0);        toast.setDuration(Toast.LENGTH_SHORT);        toast.setView(layout);        toast.show();    }    /***************************************************************    *  Purpose      - Get latest data. Fill the view, attach view and    *                 adapter, tell adapter to refresh view.     ****************************************************************/    public void refresh() throws IOException     {        Data d = new Data();        settings = getPreferences(Context.MODE_PRIVATE);        listName = settings.getString("listName", "Bruno");        adapter = new ArrayAdapter<String>(this, R.layout.list_item,                R.id.listItem, d.getItems(listName));        // Attach adapter and view, then refresh with the        // notifyDataSetChanged event        ListView myList = (ListView) findViewById(R.id.list);        myList.setAdapter(adapter);        adapter.notifyDataSetChanged();    }}                

 package com.bruno.cloudclient;import java.io.BufferedInputStream;import java.io.IOException;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import java.net.URLConnection;import java.util.ArrayList;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.client.ClientProtocolException;import org.apache.http.client.HttpClient;import org.apache.http.client.methods.HttpDelete;import org.apache.http.client.methods.HttpGet;import org.apache.http.client.methods.HttpPost;import org.apache.http.entity.ByteArrayEntity;import org.apache.http.impl.client.DefaultHttpClient;import org.json.JSONArray;import android.os.AsyncTask;public class Data {    private ArrayList<String> items;    /***************************************************************    *  Purpose      - Populate or list view control. Makes a call    *                 the web service using a hard-coded address.    *                     *     ****************************************************************     *  Assumptions  - RESTful service available with data    *     ****************************************************************     *  Effects      - none, simply reads data    *     ****************************************************************     *  Inputs       - A list (represents an android user) to     *                 that is looked up from the RESTful service    ****************************************************************     *  Returns      - A populated array (will fill the adapter    *                 which is mapped to our listbox    *     ****************************************************************/    public ArrayList<String> getItems(String listName) throws IOException     {        // ArrayList will be populated from the JSON data coming from        // the web server        items = new ArrayList<String>();                JSONArray ja = new GetShoppingListData()           .doInBackground("https://fastmotorcycleservice.cloudapp.net/FastMotorcycleListService.svc/list/"+listName);                // Loop through json array and return results to be used in         // the listbox via the adapter object        for (int i = 0; i < ja.length(); i++)         {            try             {               items.add(ja.getString(i));            }             catch (Exception e)             {                e.printStackTrace();            }        }        return items;    }    /***************************************************************    *  Purpose      - Does a delete or add asynchronously. If pass    *                 true, then an add is done. Else do delete.    ****************************************************************/    public void modifyItem(String listName, String item, boolean operation)     {        if (operation == true)         {            HttpResponse response = new AddShoppingListData()                .doInBackground(                        "https://YOUR_AZURE_SERVICE.cloudapp.net/FastMotorcycleListService.svc/list/"+listName,                    item);        }         else         {            HttpResponse response = new DeleteShoppingListData()                    .doInBackground(                            "https://YOUR_AZURE_SERVICE.cloudapp.net/FastMotorcycleListService.svc/list/"+listName,                    item);        }    }        /***************************************************************    *  Purpose      - A private class to allow:    *                 Asynchronously retrieve data from the RESTful    *                 service hosted in the cloud    ****************************************************************     *  Assumptions  - RESTful service up and and running    *     ****************************************************************     *  Inputs       - A url to look up data    *     ****************************************************************     *  Returns      - A JSON array full of data    *     ****************************************************************/    private class GetShoppingListData extends            AsyncTask<String, Void, JSONArray> {        @Override        protected JSONArray doInBackground(String... urls)         {            // HttpClient used to talk to web service.            HttpClient httpclient = new DefaultHttpClient();                        // This will be the array we need to convert. We            // get the data from the web service.            JSONArray listItems = null;            String jason = null;                        // Setup the RESTful call to 'GET' the data            HttpGet request_http_get = new HttpGet(urls[0]);                        // Read the JSON data and return            try             {                // Fill a response object using a request                HttpResponse response_http_get = httpclient.execute(request_http_get);                            // Length represents the number of data items returned                // by RESTful service                long length = response_http_get.getEntity().getContentLength();                // "entity" ends up being the data coming back from web server.                HttpEntity entity = response_http_get.getEntity();                // Read the bytes, one byte at a time.                InputStream stream = entity.getContent();                                // Allocate a series of bytes                byte[] buffer = new byte[(int) length];                                // Read bytes from RESTful service.                // After this loop, we end up with -> ["busa","gxr1000","ninja250"]                for (int i = 0; i < length; i++)                 {                    buffer[i] = (byte) stream.read();                }                // The string "buffer" looks something                 // like this -> ["busa","gxr1000","ninja250"]                jason = new String(buffer);                // Convert to Json array for Android ListBox.                // This ends up being a 3 element json array (see "busa" above)                listItems = new JSONArray(jason);            }             catch (Exception e)             {                System.out.println(e);            }            return listItems;        }    }     /***************************************************************    *  Purpose      - A class used to Post data to the RESTful service (Microsoft    *                 cloud, Azure) using Http 'POST'    ****************************************************************     *  Inputs       - (1) The service address    *                 (2) The data to be posted (what the user types in)    ****************************************************************     *  Comments     - (1) Using HttpPost for "Add" operations    *                 (2) Using UTF8 because default Android is UTF-16    ****************************************************************/    private class AddShoppingListData extends            AsyncTask<String, Void, HttpResponse> {        HttpResponse response_http;        @Override        protected HttpResponse doInBackground(String... params)         {            HttpClient httpclient = new DefaultHttpClient();            HttpPost request_add = new HttpPost(params[0]);            try {                request_add.addHeader("Content-Type", "application/json");                String postData = "\"" + params[1] + "\"";                request_add.setEntity(new ByteArrayEntity(postData.getBytes("UTF8")));                response_http = httpclient.execute(request_add);            } catch (ClientProtocolException e) {                // TODO            } catch (IOException e) {                // TODO            }            return response_http;        }    }    /***************************************************************    *  Purpose      - A class used to Post data to the RESTful service (Microsoft    *                 cloud, Azure) using Http 'POST'    ****************************************************************     *  Inputs       - (1) The service address    *                 (2) The data to be posted (what the user types in)    ****************************************************************     *  Comments     - (1) Using HttpPost for "Delete" operations    *                 (2) Fixing up spaces with s.replace()    ****************************************************************/    private class DeleteShoppingListData extends            AsyncTask<String, Void, HttpResponse> {        @Override        protected HttpResponse doInBackground(String... params)         {            HttpClient httpclient = new DefaultHttpClient();            String s = params[1];            // Fix up spaces            String charEscaped = s.replace(" ", "%20");            HttpDelete request_delete = new HttpDelete(params[0] + "/" + charEscaped);            HttpResponse response_delete = null;            try             {                // Do the RESTful delete command                response_delete = httpclient.execute(request_delete);            }             catch (ClientProtocolException e)             {                e.printStackTrace();            } catch (IOException e)             {                e.printStackTrace();            }            return response_delete;        }    }}                

 <?xml version="1.0" encoding="utf-8"?><RelativeLayout  xmlns:android="https://schemas.android.com/apk/res/android"  android:layout_width="fill_parent"  android:layout_height="fill_parent">  <ListView    android:layout_alignParentTop="true" android:id="@+id/list" android:layout_width="fill_parent" android:layout_height="fill_parent">  </ListView>  <LinearLayout    android:layout_below="@+id/ListView01" android:id="@+id/LinearLayout01" android:layout_height="wrap_content" android:layout_width="fill_parent" android:layout_alignParentBottom="true">    <EditText      android:id="@+id/txtItem"      android:layout_width="fill_parent"      android:layout_height="wrap_content"      android:layout_weight="1"      android:layout_alignParentBottom="true">    </EditText>    <Button      android:id="@+id/btnAdd"      android:layout_alignRight="@id/txtItem"      android:layout_width="fill_parent"      android:layout_height="wrap_content"      android:layout_weight="1"      android:text="Add"      android:layout_alignParentBottom="true">    </Button>  </LinearLayout></RelativeLayout>                

 <?xml version="1.0" encoding="utf-8"?><LinearLayout  xmlns:android="https://schemas.android.com/apk/res/android"  android:id="@+id/layout_root"  android:orientation="horizontal"  android:layout_width="fill_parent"  android:layout_height="fill_parent"  android:padding="10dp">  <EditText    android:id="@+id/listName"    android:layout_width="100dp"    android:layout_height="fill_parent"    android:layout_marginRight="10dp"/>  <Button    android:id="@+id/btnCreateList"    android:layout_width="100dp"    android:layout_height="fill_parent"    android:textColor="#FFF"/></LinearLayout>                

 <?xml version="1.0" encoding="utf-8"?><LinearLayout  xmlns:android="https://schemas.android.com/apk/res/android"  android:id="@+id/layout_root"  android:orientation="horizontal"  android:layout_width="fill_parent"  android:layout_height="fill_parent"  android:padding="10dp">  <EditText    android:id="@+id/listName"    android:layout_width="100dp"    android:layout_height="fill_parent"    android:layout_marginRight="10dp"/>  <Button    android:id="@+id/btnCreateList"    android:layout_width="100dp"    android:layout_height="fill_parent"    android:textColor="#FFF"/></LinearLayout>                

 <?xml version="1.0" encoding="utf-8"?><LinearLayout  xmlns:android="https://schemas.android.com/apk/res/android"  android:layout_width="wrap_content"  android:layout_height="wrap_content">  <TextView    xmlns:android="https://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:padding="10dp"    android:textSize="16sp"    android:id="@+id/listItem">  </TextView></LinearLayout>                

 <?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="https://schemas.android.com/apk/res/android"      package="com.bruno.cloudclient"      android:versionCode="1"      android:versionName="1.0">    <uses-sdk android:minSdkVersion="10" /> <uses-permission android:name="android.permission.INTERNET" />    <application android:icon="@drawable/icon" android:label="@string/app_name">        <activity android:name=".CloudClientActivity"                  android:label="@string/app_name">            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application></manifest>