mainactivity.java

package info.androidhive.introslider;

import android.annotation.SuppressLint;
import android.content.Intent;
import android.os.Bundle;
import android.support.design.widget.TextInputLayout;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.View;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
import android.os.StrictMode;
import android.os.AsyncTask;
import android.widget.ProgressBar;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class MainActivity extends AppCompatActivity {

    Toolbar toolbar;
    EditText username, password;
    TextInputLayout inputLayoutEmail, inputLayoutPassword;
    Button login;
    ProgressBar progressBar;
    Connection con;
    String un, pass, db, ip;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        inputLayoutEmail = (TextInputLayout) findViewById(R.id.input_layout_email);
        inputLayoutPassword = (TextInputLayout) findViewById(R.id.input_layout_password);
        login = (Button) findViewById(R.id.button);
        username = (EditText) findViewById(R.id.editText);
        password = (EditText) findViewById(R.id.editText2);
        progressBar = (ProgressBar) findViewById(R.id.progressBar);

        username.addTextChangedListener(new MyTextWatcher(username));
        password.addTextChangedListener(new MyTextWatcher(password));

        un = "";
        pass = "";
        db = "";
        ip = "182.255.0.151";


        login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                String usernam = username.getText().toString();
                String passwordd = password.getText().toString();
                CheckLogin checkLogin = new CheckLogin();// this is the Asynctask, which is used to process in background to reduce load on app process
                checkLogin.execute(usernam, passwordd);
            }
        });

    }

    private class MyTextWatcher implements TextWatcher {

        private View view;

        private MyTextWatcher(View view) {
            this.view = view;
        }

        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
        }

        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
        }

        public void afterTextChanged(Editable editable) {
            switch (view.getId()) {
                case R.id.editText:
                    validateUsername();
                    break;
                case R.id.editText2:
                    validatePassword();
                    break;
            }
        }
    }

    private boolean validateUsername() {
        if (username.getText().toString().trim().isEmpty())  {
            inputLayoutEmail.setError("Enter valid username !");
            requestFocus(username);
            return false;
        } else {
            inputLayoutEmail.setErrorEnabled(false);
        }
        return true;
    }

    private boolean validatePassword() {
        if (password.getText().toString().trim().isEmpty()) {
            inputLayoutPassword.setError("Enter valid password !");
            requestFocus(password);
            return false;
        } else {
            inputLayoutPassword.setErrorEnabled(false);
        }

        return true;
    }

    public class CheckLogin extends AsyncTask<String, String, String> {
        String z = "";
        Boolean isSuccess = false;

        @Override
        protected void onPreExecute() {
            progressBar.setVisibility(View.VISIBLE);
        }

        @Override
        protected void onPostExecute(String r) {
            progressBar.setVisibility(View.GONE);
            Toast.makeText(MainActivity.this, r, Toast.LENGTH_SHORT).show();
            if (isSuccess) {
                Toast.makeText(MainActivity.this, "Login Successfull", Toast.LENGTH_LONG).show();
                //finish();
            }
        }


        @Override
        protected String doInBackground(String... args) {



            String usernam = args[0];
            String passwordd = args[1];
            if (usernam.trim().equals("")){
                validateUsername();
            }
            else if(passwordd.trim().equals("")){
                    validatePassword();
                }
            /*(usernam.trim().equals("") || passwordd.trim().equals("")) {
                z = "Please enter Username and Password";*/
            else {
                try {
                    con = connectionclass(un, pass, db, ip);// Connect to database
                    if (con == null) {
                        z = "Check Your Internet Access!";
                    } else {
                        String query = "select * from tbllogin where username= '" + usernam.toString() + "' and password = '" + passwordd.toString() + "'  ";
                        Statement stmt = con.createStatement();
                        ResultSet rs = stmt.executeQuery(query);
                        if (rs.next()) {
                            z = "Login successful";
                            isSuccess = true;
                            con.close();
                        } else {
                            z = "Invalid Credentials!";
                            isSuccess = false;
                        }
                    }
                } catch (Exception ex) {
                    isSuccess = false;
                    z = ex.getMessage();
                }
            }
            return z;
        }
    }

    private void requestFocus(View view) {
        if (view.requestFocus()) {
            getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE);
        }
    }



    @SuppressLint("NewApi")
    public Connection connectionclass(String user, String password, String database, String server) {
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);
        Connection connection = null;
        String ConnectionURL = null;
        try {
            Class.forName("net.sourceforge.jtds.jdbc.Driver");
            ConnectionURL = "jdbc:jtds:sqlserver://" + server + ";" + "databaseName=" + database + ";user=" + user + ";password=" + password + ";";
            connection = DriverManager.getConnection(ConnectionURL);
        } catch (SQLException se) {
            Log.e("error here 1 : ", se.getMessage());
        } catch (ClassNotFoundException e) {
            Log.e("error here 2 : ", e.getMessage());
        } catch (Exception e) {
            Log.e("error here 3 : ", e.getMessage());
        }
        return connection;
    }

}