MDAD17: Lab9 Reading values from Text file

Lab9 :
Reading values from Text file hosted in Tomcat Server over the network

Part 1

7. Replace the contents of activity_net2.xml with the file downloaded from OLIVE.

activity_net2.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/customise"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <TextView
        android:id="@+id/tvNet2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />
    
    <Button
        android:id="@+id/btnGetConfig"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Get Config" />
</LinearLayout>

Type the following for Net2Activity.java and correct all errors with Eclipse intellisense:

package mdad.lab9;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Color;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;

public class Net2Activity extends Activity {
  static int c1=255, c2=255, c3=255; //this statement is outside of onCreate method
  String[] s=new String[3];
  TextView tv2;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);

             setContentView(R.layout.activity_net2);
      tv2 = (TextView)findViewById(R.id.tvNet2);
      tv2.setTextColor(Color.BLUE);
      tv2.setText("Red:"+c1+" Green:"+c2+" Blue:"+c3); 
    
    
        //Set background Color
        LinearLayout layout = (LinearLayout) findViewById(R.id.customise);
        layout.setBackgroundColor(Color.rgb(c1, c2, c3));
        Button btnGetConfig = (Button)findViewById(R.id.btnGetConfig);
        btnGetConfig.setOnClickListener(new OnClickListener(){
         public void onClick(View v){
          
         new NetworkTask().execute("http://10.0.2.2:8080/MDAD/html/config.txt");
          
           
                 }  });
  
 }
 //AsyncTask inner class needed because of StrictMode to ensure network tasks are on separate threads
 private class NetworkTask extends AsyncTask<String, Void, String>{

  protected String doInBackground(String... params) {
   
       
   String a = params[0];
      try{
       System.out.println("NetworkTask started……"); //print to logcat for debugging
    URL url = new URL(a);
 HttpURLConnection con = (HttpURLConnection)url.openConnection();
   con.setRequestProperty("Accept", "text/plain");
 BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream()));
  
    String line;
    int i=0;
    while((line=br.readLine())!=null) {  //read values from config.txt in the server over the network
       s[i]=line;
       
       System.out.println(s[i]);
       i++;
        }
    Net2Activity.c1 = Integer.parseInt(s[0]);//convert to integer
        Net2Activity.c2 = Integer.parseInt(s[1]);
        Net2Activity.c3 = Integer.parseInt(s[2]);
     con.disconnect();
        }
        catch(IOException e){ Log.e("error", "error in reading", e); }
      
  
      
      return "Red:"+s[0]+" Green:"+s[1]+" Blue:"+s[2];
  }
  protected void onPostExecute(String result) {
   
   tv2.setTextColor(Color.RED);
   
         tv2.setText(result);
      LinearLayout layout = (LinearLayout) findViewById(R.id.customise);
         layout.setBackgroundColor(Color.rgb(c1, c2, c3));
    }//end onPostExecute
 }//end of inner class NetworkTask
 @Override
 public boolean onCreateOptionsMenu(Menu menu) {
  // Inflate the menu; this adds items to the action bar if it is present.
  getMenuInflater().inflate(R.menu.net2, menu);
  return true;
 }

}//end of Net2Activity class

Part 2

activity_about.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".About" >

    <TextView
        android:id="@+id/tvAbout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="23dp"
        android:text="TextView" />

</RelativeLayout>

Look at the onCreate method of NetworkingActivity.java.
You need to add one more menu item. Fill in the blank below:

package mdad.lab9;


import java.util.SortedMap;
import java.util.TreeMap;

import android.os.Bundle;
import android.app.Activity;
import android.app.ListActivity;
import android.content.Intent;
import android.graphics.Color;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.ListView;

public class NetworkingActivity extends ListActivity {
 SortedMap<String, Object> actions = new TreeMap<String, Object>();
 
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);



       addMenuItem("Read text file from server", Net2Activity.class);
       addMenuItem("About Us", About.class);

        String[] keys = actions.keySet().toArray(
    new String[actions.keySet().size()]);

  setListAdapter(new ArrayAdapter<String>(this,
    android.R.layout.simple_list_item_1, keys));
    }

    public void addMenuItem(String label, Class<?> cls){
  actions.put(label, new Intent(this, cls ));
 }
    protected void onListItemClick(ListView l, View v, int position, long id) {
  String key = (String) l.getItemAtPosition(position);
  startActivity((Intent) actions.get(key));
 }
}

4. Look at the onCreate method of NetworkingActivity.java. You need to add one more menu item. Fill in the blank below:

package mdad.lab9;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.widget.TextView;

public class About extends Activity {

 TextView tv3;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_about);
  tv3 = (TextView)findViewById(R.id.tvAbout);

      new AboutTask().execute("http://10.0.2.2:8080/MDAD/html/about.txt");
 }
 private class AboutTask extends AsyncTask<String, Void, String>{

  @Override
  protected String doInBackground(String... params) {
   String a = params[0], s="";
      try{
       URL url = new URL(a);
          HttpURLConnection con = (HttpURLConnection)url.openConnection();
       con.setRequestProperty("Accept", "text/plain");
    BufferedReader br = new BufferedReader(new InputStreamReader(con.getInputStream()));

    String line;
    while((line=br.readLine())!=null) {
       s+=line+"\n";
        }

     con.disconnect();
        }
        catch(IOException e){ Log.e("error", "error in reading", e); }
   return s;
  }


  protected void onPostExecute(String result) {
         tv3.setText(result);
    }
 }

}

MDAD17

Lab9 Reading values from Text file

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