ButterKnife

Under Gradle.app, add the following dependencies:

dependencies {
    ...
    compile 'com.jakewharton:butterknife:8.5.1'
    annotationProcessor 'com.jakewharton:butterknife-compiler:8.5.1'
}

Under MainActivity, Annotate it by @BindView

@BindView(R.id.butterToast) EditText butterToast;

It will replace the line:
private EditText butterToast = (EditText) findViewByID(R.id.butterToast);

Under onCreate(Bundle savedInstanceState){}

        ButterKnife.bind(this);




Annotate methods outside onCreate(Bundle savedInstanceState)

@OnClick(R.id.button)
    public void submit() {
        Toast.makeText(MainActivity.this,
                "Hello from Butterknife OnClick annotation", Toast.LENGTH_SHORT).show();
    }


Import the following Classes:

import butterknife.BindView;
import butterknife.ButterKnife;
import butterknife.OnClick;


http://www.vogella.com/tutorials/AndroidButterknife/article.html#exercise-using-butterknife-in-your-android-project