Here is the full source code to create to create Press Back Again to Exit using java
MainActivity.java
package com.example.application.exampleapp;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private long backPressedTime;
private Toast backToast;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@Override
public void onBackPressed() {
if (backPressedTime + 2000 > System.currentTimeMillis()) {
backToast.cancel();
super.onBackPressed();
return;
} else {
backToast = Toast.makeText(getBaseContext(), "Press back again to exit", Toast.LENGTH_SHORT);
backToast.show();
}
backPressedTime = System.currentTimeMillis();
}
}