Read and write in a file using Asynctask

/*******************ReadWebpageAsyncTaskActivity*************************/
package com.asynctask.android;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.app.Activity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class ReadWebpageAsyncTaskActivity extends Activity {
        private TextView textView;
        Button btn_readWebpage;
        Button btn_write;
        String file_name;
 
@Override
public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        textView = (TextView) findViewById(R.id.TextView01);
        btn_readWebpage = (Button) findViewById(R.id.readWebpage);
    }

private class DownloadWebPageTask extends AsyncTask<String, Void, String> {

       @Override
        protected String doInBackground(String... urls) {
            String response = "";
            for (String url : urls) {
                  DefaultHttpClient client = new DefaultHttpClient();
                  HttpGet httpGet = new HttpGet(url);
                  try {
                            HttpResponse execute = client.execute(httpGet);
                            InputStream content = execute.getEntity().getContent();
                                         BufferedReader buffer = new BufferedReader(new InputStreamReader(content));
                             file_name = ReadWebpageAsyncTaskActivity.this.getFilesDir()
        .getAbsolutePath() + "/text.txt";

                          // file_name = Environment.getExternalStorageDirectory(
                                                                 // "/textFile.txt";

                                       File file = new File(file_name);
                            boolean exist = file.createNewFile();
                            if (!exist)
                            System.out.println("File already exists.");

                                        FileWriter fstream = new FileWriter(file_name);
                                BufferedWriter out = new BufferedWriter(fstream);
                                String s = "";
                                while ((s = buffer.readLine()) != null) {
                                    response += s;
                                out.write(s);
                                }
                                out.close();
                                System.out.println("File created successfully.");

                    } catch (Exception e) {
                    e.printStackTrace();
                    }
                    }
                        Log.d("\nResponse========: ", "String" + response);
                    return response;
                }

                @Override
                protected void onPostExecute(String response) {
                // textView.setText(response);
                String result = "";
                String strLine;
                File file = new File(file_name);
                FileInputStream fin;

                try {
                    fin = new FileInputStream(file);
                    BufferedReader br = new BufferedReader(new InputStreamReader(fin));
                    while ((strLine = br.readLine()) != null) {
                    result += strLine;
                }
                textView.setText(result);
                } catch (FileNotFoundException e) {
                       e.printStackTrace();
                } catch (IOException e) {
                           e.printStackTrace();
                }
                }
                }

        public void readWebpage(View view) {
           DownloadWebPageTask task = new DownloadWebPageTask();
                task.execute(new String[] { "http://www.vogella.de" });
        }
}


/***************************main.xml***************************/

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:orientation="vertical" >

<Button

android:id="@+id/readWebpage"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="Load Webpage"

android:onClick="readWebpage">

</Button>

<TextView

android:id="@+id/TextView01"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:text="Example Text" >

</TextView>

</LinearLayout>

Download an image using Asynctask with ProgressDialog

/***********************DownloadActivity.java********************/
package com.image.download;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.net.URLConnection;

import org.apache.http.util.ByteArrayBuffer;

import android.app.Activity;
import android.app.Dialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class DownloadActivity extends Activity {
 
    public static final int DIALOG_DOWNLOAD_PROGRESS = 0;
    private Button startBtn;
    private ProgressDialog mProgressDialog;
 
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        startBtn = (Button)findViewById(R.id.startBtn);
        startBtn.setOnClickListener(new OnClickListener(){
            public void onClick(View v) {
                startDownload();
            }
        });
    }

    private void startDownload() {
        //String url = "http://www.mobilemarketingwatch.com/wordpress/wp-content/uploads/2010/04/Android-Growing-Quickly-App-Growth-Up-70-Percent-60K-Activations-Per-Day-300x300.jpg";
        String url = "http://cache.gawkerassets.com/assets/images/4/2011/11/2caf61af0c8d4d4beba307403e7d44da.jpg";
        new DownloadFileAsync().execute(url);
    }

    public class DownloadFileAsync extends AsyncTask<String, String, String> {

    @Override
    protected void onPreExecute() {
mProgressDialog = new ProgressDialog(DownloadActivity.this);
mProgressDialog.setMessage("Downloading file..");
mProgressDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
mProgressDialog.setCancelable(false);
mProgressDialog.setMax(100);
mProgressDialog.show();
    }

    @Override
    protected String doInBackground(String... aurl) {
    int count;
   
    try {

           URL url = new URL(aurl[0]);
           Log.d("\nANDRO_ASYNC", "doInBackground.................................. ");
               
                String fileName = DownloadActivity.this.getFilesDir().getAbsolutePath()+"/newPhoto.jpg";    // /data/data/com.image.download/files
           String filePath = Environment.getExternalStorageDirectory() + "/phone.jpg"; // /sdcard

           Log.d("Name ******************** ", ""+ Environment.getExternalStorageDirectory());
                Log.d("\nFILENAME:   ", " "+DownloadActivity.this.getFilesDir().getAbsolutePath());
             
File file = new File(filePath);
                long startTime = System.currentTimeMillis();

                Log.d("\nImageManager", "download url:" + url);
                Log.d("\nImageManager", "downloaded file name:" + filePath);

                URLConnection ucon = url.openConnection();
                InputStream is = ucon.getInputStream();
                BufferedInputStream bis = new BufferedInputStream(is);

                int lenghtOfFile = ucon.getContentLength();
           Log.d("\nANDRO_ASYNC", "Lenght of file: " + lenghtOfFile);

                ByteArrayBuffer baf = new ByteArrayBuffer(50);
                int current = 0;
                byte[] buffer = new byte[1024];
                int len1 = 0;
                long total = 0;
             
                while ((len1 = is.read(buffer)) > 0) {
                    total += len1;
                    publishProgress("" + (int)((total*100)/lenghtOfFile));              
                    baf.append((byte) current);
                }
             
                FileOutputStream fos = new FileOutputStream(file);
                fos.write(baf.toByteArray());
                fos.close();

                Log.d("\nImageManager", "download ready in"+ ((System.currentTimeMillis() - startTime) / 1000));

    } catch (Exception e) {
    Log.d("Exception: ", e.getMessage());
    }
    return null;
    }

@Override
protected void onProgressUpdate(String... progress) {
mProgressDialog.incrementProgressBy(Integer.parseInt(progress[0]));
}

    @Override
    protected void onPostExecute(String unused) {
    mProgressDialog.dismiss();
    }
    }
}

/***************************main.xml***************************/

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />

    <Button
        android:id="@+id/startBtn"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="start" >
    </Button>

</LinearLayout>

Asynchronous Tasks with Android

Login Page Design with background images and imagebuttons

/**************************main.xml*********************/

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:orientation="vertical" >

<RelativeLayout

android:layout_width="300dp"

android:layout_height="180dp"

android:layout_gravity="center"

android:layout_marginTop="30dp"

android:background="@drawable/band" >

<TextView

android:id="@+id/txt_user"

android:layout_width="wrap_content"

android:layout_height="30dp"

android:layout_marginLeft="20dp"

android:layout_marginTop="20dp"

android:gravity="center"

android:text="@string/username"

android:textColor="#000" />

<EditText

android:id="@+id/m_username"

android:layout_width="180dp"

android:layout_height="30dp"

android:layout_marginLeft="10dp"

android:layout_marginTop="20dp"

android:layout_toRightOf="@+id/txt_user"

android:textSize="10sp" />

<TextView

android:id="@+id/txt_pass"

android:layout_width="wrap_content"

android:layout_height="30dp"

android:layout_below="@+id/txt_user"

android:layout_marginLeft="20dp"

android:layout_marginTop="20dp"

android:gravity="center"

android:text="@string/password"

android:textColor="#000" />

<EditText

android:id="@+id/m_password"

android:layout_width="180dp"

android:layout_height="30dp"

android:layout_below="@+id/m_username"

android:layout_marginLeft="15dp"

android:layout_marginTop="20dp"

android:layout_toRightOf="@+id/txt_pass"

android:textSize="10sp" />

<TextView

android:id="@+id/txt_forget"

android:layout_width="fill_parent"

android:layout_height="30dp"

android:layout_below="@+id/txt_pass"

android:layout_marginLeft="15dp"

android:gravity="center"

android:text="Forget ur password?"

android:textColor="#000" />

<ImageButton

android:id="@+id/btn_login"

android:layout_width="60dp"

android:layout_height="30dp"

android:layout_below="@+id/txt_forget"

android:layout_marginLeft="100dp"

android:layout_marginTop="10dp"

android:background="@drawable/login"

android:focusable="true" >

</ImageButton>

<ImageButton

android:id="@+id/btn_cancel"

android:layout_width="60dp"

android:layout_height="30dp"

android:layout_below="@+id/txt_forget"

android:layout_marginLeft="20dp"

android:layout_marginTop="10dp"

android:layout_toRightOf="@+id/btn_login"

android:background="@drawable/cancel"

android:focusable="true" />

</RelativeLayout>

<Button

android:id="@+id/btn_show"

android:layout_width="100dp"

android:layout_height="40dp"

android:layout_gravity="center_horizontal"

android:layout_marginTop="20dp"

android:text="All Users" />

<TextView

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:layout_marginTop="10dp"

android:gravity="center"

android:text="NEW USER??"

android:textColor="#fff" />

<Button

android:id="@+id/btn_register"

android:layout_width="fill_parent"

android:layout_height="40dp"

android:text="Register" />

<ListView

android:id="@+id/listView1"

android:layout_width="fill_parent"

android:layout_height="wrap_content" >

</ListView>

</LinearLayout>

Insert, View, delete, count options done using Sqlite database

/**********************MySQLiteHelper*************************/

package com.sampleapp.application;

import android.content.Context;

import android.database.sqlite.SQLiteDatabase;

import android.database.sqlite.SQLiteOpenHelper;

import android.util.Log;

public class MySQLiteHelper extends SQLiteOpenHelper {

MySQLiteHelper dbHelper;

SQLiteDatabase database;

public static class EmpTable{

static final String TABLE_NAME = "employee";

static final String EMP_ID = "_id";

static final String EMP_NAME = "name";

static final String EMP_DESIGNATION = "designation";

static final String EMP_COMPANY = "company";

static final String EMP_MOBILE = "mobile";

static final String EMP_ADDRESS = "address";

}

public static final String TABLE_COMMENTS = "comments";

public static final String COLUMN_ID = "_id";

public static final String COLUMN_COMMENT = "comment";

public static final String DATABASE_NAME = "comments.db";

private static final int DATABASE_VERSION = 1;

private String[] allColumns = { COLUMN_ID, COLUMN_COMMENT };

// Database creation sql statement

public static final String DATABASE_CREATE = "create table "

+ TABLE_COMMENTS + "( " + COLUMN_ID

+ " integer primary key autoincrement, " + COLUMN_COMMENT

+ " text not null);";

public static final String CREATE_EMP_TABLE = "create table "

+ EmpTable.TABLE_NAME + "( " + EmpTable.EMP_ID

+ " integer primary key autoincrement, "

+ EmpTable.EMP_NAME + " text not null, "

+ EmpTable.EMP_DESIGNATION + " text not null, "

+ EmpTable.EMP_COMPANY + " text not null, "

+ EmpTable.EMP_MOBILE + " real, "

+ EmpTable.EMP_ADDRESS + " text);";

public MySQLiteHelper(Context context) {

super(context, DATABASE_NAME, null, DATABASE_VERSION);

}

@Override

public void onCreate(SQLiteDatabase database) {

database.execSQL(DATABASE_CREATE);

database.execSQL(CREATE_EMP_TABLE);

Log.d("\n\nMySQLiteHelper***", "Table Created");

}

@Override

public void onUpgrade(SQLiteDatabase database, int oldVersion, int newVersion) {

Log.w(MySQLiteHelper.class.getName(),

"Upgrading database from version " + oldVersion + " to "

+ newVersion + ", which will destroy all old data");

database.execSQL("DROP TABLE IF EXISTS " + TABLE_COMMENTS);

database.execSQL("DROP TABLE IF EXISTS " + EmpTable.TABLE_NAME);

onCreate(database);

Log.d("\n\nMySQLiteHelper***", "Table Upgraded");

}

}

/*************************CommentsDataSource.java****************************/

package com.sampleapp.application;

import com.sampleapp.application.MySQLiteHelper.EmpTable;

import android.app.Activity;

import android.content.ContentValues;

import android.content.Context;

import android.database.Cursor;

import android.database.DatabaseUtils;

import android.database.SQLException;

import android.database.sqlite.SQLiteDatabase;

import android.util.Log;

public class CommentsDataSource {

private SQLiteDatabase database;

private MySQLiteHelper dbHelper;

public CommentsDataSource(Context context) {

dbHelper = new MySQLiteHelper(context);

}

public void open() throws SQLException {

database = dbHelper.getWritableDatabase();

Log.d("/nDATABASE OPENED************", "OPENED");

}

public void close() {

dbHelper.close();

Log.d("/nDATABASE CLOSED************", "CLOSED");

}

public void createComment(String comment) {

ContentValues values = new ContentValues();

values.put(MySQLiteHelper.COLUMN_COMMENT, comment);

database.insert(MySQLiteHelper.TABLE_COMMENTS, null, values);

Log.d("\nINSERT", "Inserted the data..\n");

}

public Cursor all(Activity activity) {

String[] from = { MySQLiteHelper.COLUMN_ID,

MySQLiteHelper.COLUMN_COMMENT };

String order = MySQLiteHelper.COLUMN_ID;

Cursor cursor = database.query(MySQLiteHelper.TABLE_COMMENTS, from,

null, null, null, null, order);

activity.startManagingCursor(cursor);

return cursor;

}

public int count() {

return (int) DatabaseUtils.queryNumEntries(database,

MySQLiteHelper.TABLE_COMMENTS);

}

public void deleteComment(long id) {

System.out.println("Comment deleted with id: " + id);

database.delete(MySQLiteHelper.TABLE_COMMENTS, MySQLiteHelper.COLUMN_ID

+ " = " + id, null);

}

public void createEmployee(String name, String degn, String cmpy, int mob,

String address) {

ContentValues values = new ContentValues();

values.put("name", name);

values.put("designation", degn);

values.put("company", cmpy);

values.put("mobile", mob);

values.put("address", address);

try {

database.insertOrThrow(EmpTable.TABLE_NAME, null, values);

Log.v("\nINSERT IN Employee table", "Inserted a row..\n");

} catch (SQLException e) {

Log.e(MySQLiteHelper.DATABASE_NAME, e.toString());

}

}

public Cursor allEmployees(Activity activity) {

String[] from = { EmpTable.EMP_ID, EmpTable.EMP_NAME,

EmpTable.EMP_DESIGNATION, EmpTable.EMP_COMPANY,

EmpTable.EMP_MOBILE, EmpTable.EMP_ADDRESS };

String order = EmpTable.EMP_ID;

Cursor cursor = database.query(EmpTable.TABLE_NAME, from,

null, null, null, null, order);

activity.startManagingCursor(cursor);

return cursor;

}

/* public void createTable(){

database.execSQL(MySQLiteHelper.CREATE_EMP_TABLE);

}

public void dropTable(){

database.execSQL("DROP TABLE IF EXISTS " + EmpTable.TABLE_NAME);

}*/

}

/**************************LoginActivity.java***************************/

package com.sampleapp.application;

import android.app.Activity;

import android.app.Notification;

import android.app.NotificationManager;

import android.app.PendingIntent;

import android.content.Intent;

import android.database.Cursor;

import android.os.Bundle;

import android.util.Log;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemLongClickListener;

import android.widget.Button;

import android.widget.EditText;

import android.widget.ListView;

import android.widget.SimpleCursorAdapter;

import android.widget.Toast;

public class LoginActivity extends Activity implements OnClickListener {

protected static final int LENGTH_SHORT = 0;

Button btn_view;

Button btn_count;

Button btn_insert;

Button btn_delete;

EditText new_data;

EditText del_data;

int count_comment;

Comment comment;

private CommentsDataSource datasource;

SimpleCursorAdapter adapter;

Cursor cursor;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.register);

datasource = new CommentsDataSource(this);

btn_view = (Button) findViewById(R.id.btn_view);

btn_view.setOnClickListener(this);

btn_insert = (Button) findViewById(R.id.btn_insert);

btn_insert.setOnClickListener(this);

btn_delete = (Button) findViewById(R.id.btn_delete);

btn_delete.setOnClickListener(this);

btn_count = (Button) findViewById(R.id.btn_count);

btn_count.setOnClickListener(this);

NotificationManager mNotificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);

Notification notification = new Notification(R.drawable.notification_icon, "Hello......", System.currentTimeMillis());

Intent notificationIntent = new Intent(this, LoginActivity.class);

PendingIntent contentIntent = PendingIntent.getActivity(this, 0, notificationIntent, 0);

notification.setLatestEventInfo(getApplicationContext(), "My notification", "Hello World!", contentIntent);

final int HELLO_ID = 1;

mNotificationManager.notify(HELLO_ID, notification);

}

@Override

public void onClick(View v) {

switch (v.getId()) {

case R.id.btn_delete:

             count_comment = (int) datasource.count();

             del_data = (EditText) findViewById(R.id.del_data);

             int delData = Integer.parseInt(del_data.getText().toString());

             if (delData <= count_comment)

             datasource.deleteComment((int) delData);

             Log.d("\nDELETED PARTICULAR DATA ************", "NUMBER -> " +                            delData);

break;

case R.id.btn_count:

             count_comment = (int) datasource.count();

             System.out.println("\nCOUNT------------" + count_comment);

             Toast.makeText(getApplicationContext(), "Total comments: "+count_comment,

Toast.LENGTH_LONG).show();

break;

case R.id.btn_insert:

             new_data = (EditText) findViewById(R.id.new_data);

             String newData = new_data.getText().toString();

             datasource.createComment(newData);

break;

case R.id.btn_view:

             String[] from = new String[] { MySQLiteHelper.COLUMN_ID ,              MySQLiteHelper.COLUMN_COMMENT };

             int[] to = new int[] { R.id.col_id, R.id.label };

             cursor = datasource.all(this);

             adapter = new SimpleCursorAdapter(this, R.layout.list_item, cursor,

from, to);

             ListView av = (ListView) findViewById(R.id.comment_list);

             av.setAdapter(adapter);

             av.setFastScrollEnabled(true);

             av.setTextFilterEnabled(true);

             av.setOnItemLongClickListener(new OnItemLongClickListener() {

             @Override

                          public boolean onItemLongClick(AdapterView<?> arg0, View v,

                                       int clickedPos, long id) {

             

                                       // dataAdapter.remove(dataAdapter.getItem(clickedpos));

                                       // dataAdapter.insert(t.getText().toString(), clickedpos);

                          Toast.makeText(LoginActivity.this, "Pos: "+ clickedPos, Toast.LENGTH_SHORT);

                                       Log.d("LONG CLICK---------", "clicked --> "+clickedPos);

                                       return true;

                          }

             });

break;

}

}

@Override

protected void onPause() {

datasource.close();

super.onPause();

}

@Override

protected void onResume() {

datasource.open();

super.onResume();

}

}

/********************Comment.java*********************/

package com.sampleapp.application;

public class Comment {

private long id;

private String comment;

public long getId() {

return id;

}

public void setId(long id) {

this.id = id;

}

public String getComment() {

return comment;

}

public void setComment(String comment) {

this.comment = comment;

}

// Will be used by the ArrayAdapter in the ListView

@Override

public String toString() {

return comment;

}

}

/*********************register.xml***********************/

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:orientation="vertical" >

<RelativeLayout

android:layout_width="fill_parent"

android:layout_height="wrap_content" >

<Button

android:id="@+id/btn_count"

android:layout_width="100dp"

android:layout_height="wrap_content"

android:layout_gravity="center_vertical"

android:text="@string/count" >

</Button>

<Button

android:id="@+id/btn_view"

android:layout_width="100dp"

android:layout_height="wrap_content"

android:layout_gravity="center_vertical"

android:layout_toRightOf="@+id/btn_count"

android:text="@string/view" >

</Button>

<EditText

android:id="@+id/new_data"

android:layout_width="100dp"

android:layout_height="wrap_content"

android:layout_below="@+id/btn_count" >

<requestFocus />

</EditText>

<Button

android:id="@+id/btn_insert"

android:layout_width="100dp"

android:layout_height="wrap_content"

android:layout_gravity="center_vertical"

android:layout_toRightOf="@+id/new_data"

android:text="@string/insert"

android:layout_below="@+id/btn_view">

</Button>

<EditText

android:id="@+id/del_data"

android:layout_width="100dp"

android:layout_height="wrap_content"

android:layout_below="@+id/new_data">

</EditText>

<Button

android:id="@+id/btn_delete"

android:layout_width="100dp"

android:layout_height="wrap_content"

android:layout_gravity="center_vertical"

android:layout_toRightOf="@+id/del_data"

android:text="@string/delete"

android:layout_below="@+id/btn_insert">

</Button>

</RelativeLayout>

<ListView

android:id="@+id/comment_list"

android:layout_width="fill_parent"

android:layout_height="wrap_content" />

</LinearLayout>

/*********************IMAGE VIEW**********************/