Android Login Screen Tutorial

DBAdapter.java:-


package com.my.members;



import android.content.ContentValues;

import android.content.Context;

import android.database.SQLException;
import android.database.Cursor;

public class DBAdapter 
import android.database.sqlite.SQLiteDatabase;



{

	public static final String KEY_ROW_ID = "_id";
private static final String DATABASE_TABLE = "members";

	public static final String KEY_PASSWORD = "password";
public static final String KEY_USERNAME = "username";
	
	
	SQLiteDatabase mDb;
	Context mCtx;

	public DBAdapter open() throws SQLException
DBHelper mDbHelper;
	
	public DBAdapter(Context context)
	{
		this.mCtx = context;
	}

	{

	{
mDbHelper = new DBHelper(mCtx);
		mDb = mDbHelper.getWritableDatabase();
		return this;
	}
	
	public void close()

		ContentValues initialValues = new ContentValues();
mDbHelper.close();
	}
	
	public long register(String user,String pw)
	{
		initialValues.put(KEY_USERNAME, user);

	public boolean Login(String username, String password) throws SQLException 
initialValues.put(KEY_PASSWORD, pw);
		
		return mDb.insert(DATABASE_TABLE, null, initialValues);
	}
	
    {

        if (mCursor != null) {           
Cursor mCursor = mDb.rawQuery("SELECT * FROM " + DATABASE_TABLE + " WHERE username=? AND password=?", new String[]{username,password});
            if(mCursor.getCount() > 0)
            {
            	return true;
            }
        }

}
return false;

    }




DBHelper.java:-


package com.my.members;



import android.content.Context;


import android.database.sqlite.SQLiteDatabase;

import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;


	private static final String DATABASE_NAME = "membersdb";
public class DBHelper extends SQLiteOpenHelper {

	private static final int DATABASE_VERSION = 1;

	private static final String DATABASE_CREATE = "CREATE TABLE  (_id integer primary key autoincrement,username text not null,password text not null);";
	public DBHelper(Context context) {
		super(context, DATABASE_NAME, null, DATABASE_VERSION);
		
	}

	@Override
	public void onCreate(SQLiteDatabase db) {
		db.execSQL(DATABASE_CREATE);

	}

	@Override

}
	public void onUpgrade(SQLiteDatabase db, int arg1, int arg2) {
		db.execSQL("DROP TABLE IF EXISTS members");
		onCreate(db);

	}




MemberActivity.java:-


package com.my.members;



import android.app.Activity;


import android.content.Context;

import android.database.SQLException;
import android.os.Bundle;

import android.view.View;
import android.util.Log;

import android.view.inputmethod.InputMethodManager;
import android.view.View.OnClickListener;

import android.widget.Toast;
import android.widget.Button;
import android.widget.EditText;


	EditText txtUserName;
public class MembersActivity extends Activity {
	DBAdapter dbAdapter;
	EditText txtPassword;
	Button btnLogin;

		super.onCreate(savedInstanceState);
	Button btnRegister;

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


		btnLogin = (Button) findViewById(R.id.btn_login);
		txtUserName = (EditText) findViewById(R.id.et_user);
		txtPassword = (EditText) findViewById(R.id.et_pw);
		btnRegister = (Button) findViewById(R.id.btn_reg);


				InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
		dbAdapter = new DBAdapter(this);
		dbAdapter.open();

		btnLogin.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View arg0) {


				String password = txtPassword.getText().toString();
				imm.hideSoftInputFromWindow(txtUserName.getWindowToken(), 0);
				imm.hideSoftInputFromWindow(txtPassword.getWindowToken(), 0);
				String username = txtUserName.getText().toString();

									.show();
				if (username.length() > 0 && password.length() > 0) {
					try {

						if (dbAdapter.Login(username, password)) {
							Toast.makeText(MembersActivity.this,
									"Successfully Logged In", Toast.LENGTH_LONG)
						} else {

								Toast.LENGTH_LONG).show();
							Toast.makeText(MembersActivity.this,
									"Invalid username or password",
									Toast.LENGTH_LONG).show();
						}

					} catch (Exception e) {
						Toast.makeText(MembersActivity.this, "Some problem occurred",

					}
				} else {

				InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
					Toast.makeText(MembersActivity.this,
							"Username or Password is empty", Toast.LENGTH_LONG).show();
				}
			}
		});

		btnRegister.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View arg0) {

					long i = dbAdapter.register(username, password);
				imm.hideSoftInputFromWindow(txtUserName.getWindowToken(), 0);
				imm.hideSoftInputFromWindow(txtPassword.getWindowToken(), 0);
				try {

					String username = txtUserName.getText().toString();
					String password = txtPassword.getText().toString();
					if(i != -1)

}
						Toast.makeText(MembersActivity.this, "You have successfully registered",Toast.LENGTH_LONG).show();

				} catch (SQLException e) {
					Toast.makeText(MembersActivity.this, "Some problem occurred",
							Toast.LENGTH_LONG).show();

				}
				
			}
		});

	}




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" android:textSize="40dp" android:layout_gravity="right" android:layout_marginBottom="10dp" android:layout_marginLeft="30dp"/>

    <TableLayout
        android:id="@+id/tableLayout1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >

        <TableRow
            android:id="@+id/tableRow1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" >
        </TableRow>

        <TableRow
            android:id="@+id/tableRow2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" >

            <EditText
                android:id="@+id/et_user"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" android:width="250dp" android:layout_marginLeft="30dp" android:layout_marginBottom="10dp" android:hint="@string/u">

                <requestFocus />
            </EditText>

        </TableRow>

        <TableRow
            android:id="@+id/tableRow3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" >

            <EditText
                android:id="@+id/et_pw"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:inputType="textPassword" android:layout_marginLeft="30dp" android:layout_marginBottom="10dp" android:hint="@string/p"/>

        </TableRow>

        <TableRow
            android:id="@+id/tableRow4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" >

            <Button
                android:id="@+id/btn_login"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/l" android:layout_marginLeft="30dp" android:layout_marginBottom="10dp" android:textSize="20dp"/>

        </TableRow>
        
         <TableRow
            android:id="@+id/tableRow5"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" >

            <Button
                android:id="@+id/btn_reg"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="@string/r" android:layout_marginLeft="30dp" android:layout_marginBottom="10dp" android:textSize="20dp"/>

        </TableRow>
    </TableLayout>

</LinearLayout>