package com.myappcompany.rob.logindemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    public void login(View view) {

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

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

        Log.i("Info", "Button pressed");

        Log.i("Username", usernameEditText.getText().toString());

        Log.i("Password", passwordEditText.getText().toString());

        Toast.makeText(this, "Hi there!", Toast.LENGTH_SHORT).show();

    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

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example 2

package com.myappcompany.rob.toastdemo;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    public void buttonClicked(View view) {

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

        Toast.makeText(this, "Hello " + editText.getText().toString(), Toast.LENGTH_LONG).show();

    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}