// XML file // JAVA file package com.example.harshitgokharu.attendancemanager; import android.content.Intent; import android.support.annotation.NonNull; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.support.v7.widget.CardView; import android.view.View; import android.widget.EditText; import android.widget.Toast; import com.google.android.gms.tasks.OnCompleteListener; import com.google.android.gms.tasks.Task; import com.google.firebase.auth.AuthResult; import com.google.firebase.auth.FirebaseAuth; import com.google.firebase.auth.FirebaseUser; public class MainActivity extends AppCompatActivity { EditText user; EditText pass; CardView card; FirebaseAuth fire; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); user=(EditText)findViewById(R.id.user); pass=(EditText)findViewById(R.id.pass); card=(CardView)findViewById(R.id.card); card.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if(validate()) { String user1= user.getText().toString(); String pass1= pass.getText().toString(); fire.signInWithEmailAndPassword(user1,pass1).addOnCompleteListener(new OnCompleteListener() { @Override public void onComplete(@NonNull Task task) { if(task.isSuccessful()) { Toast.makeText(MainActivity.this,"Login Successful",Toast.LENGTH_SHORT).show(); startActivity(new Intent(MainActivity.this,SecondActivity.class)); } else { Toast.makeText(MainActivity.this,"Login Failed",Toast.LENGTH_SHORT).show(); } } }); }; } }); fire=FirebaseAuth.getInstance(); FirebaseUser user=fire.getCurrentUser(); if(user!=null) { finish(); startActivity(new Intent(MainActivity.this,SecondActivity.class)); } } private Boolean validate() { Boolean result=false; String user1= user.getText().toString(); String pass1= pass.getText().toString(); if(user1.isEmpty() || pass1.isEmpty()) { Toast.makeText(this,"Please enter all the details",Toast.LENGTH_SHORT).show(); } else { result=true; } return result; } }

Android-firebase