How to get a Hash to use in Facebook - Easy Way

MainActivity.java

// 1- Past this code within your onCreate.
// 2- Run your app.
// 3- Check your logcat!

public class MainActivity extends AppCompatActivity {

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

        // Add code to print out the key hash
        try {
            PackageInfo info = getPackageManager().getPackageInfo(
                    getPackageName(),  //Or replace to your package name directly, instead getPackageName()  "com.your.app" 
                    PackageManager.GET_SIGNATURES);

            for (Signature signature : info.signatures) {
                MessageDigest md = MessageDigest.getInstance("SHA");
                md.update(signature.toByteArray());

                Log.e("KeyHash:", Base64.encodeToString(md.digest(), Base64.DEFAULT));
            }
        } catch (PackageManager.NameNotFoundException | NoSuchAlgorithmException e) {

        }
    }