XML FILE..

xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">

    <EditText
        android:id="@+id/edt_1"
        android:layout_width="325dp"
        android:layout_height="45dp"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="172dp"


        android:hint="@string/ed_usr"
        android:inputType="text" />

    <EditText
        android:id="@+id/edt_2"
        android:layout_width="325dp"
        android:layout_height="45dp"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="215dp"



        android:ems="10"
        android:hint="@string/ed_psw"
        android:inputType="textPassword" />

    <TextView
        android:id="@+id/textView4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginBottom="85dp"
        android:text="@string/tv_reg"
        android:textSize="17sp"
        android:textColor="#FF000000"/>

    <Button
        android:id="@+id/btn_log"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
      android:layout_centerHorizontal="true"
android:layout_marginBottom="142dp"
android:text="@string/btn_lgn" />


</RelativeLayout>


JAVA FILE..
package com.example.sardaralialam.mazdoor;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity extends AppCompatActivity {

EditText ed_user , ed_pass ;
Button btn_log ;
String user , pass;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ed_user = findViewById(R.id.edt_1);
ed_pass = findViewById(R.id.edt_2);

user = ed_user.getText().toString();
pass =ed_pass.getText().toString();
btn_log.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v)
Intent it = new Intent(MainActivity.this ,
MainActivity.class);

startActivity(it);
});
}
}


enter code here