add an icon to action bar menu code example

Example 1: android java display icon in action bar

getSupportActionBar().setDisplayShowHomeEnabled(true);
getSupportActionBar().setLogo(R.mipmap.ic_launcher);
getSupportActionBar().setDisplayUseLogoEnabled(true);

Example 2: android java display icon in action bar

ActionBar actionBar = getActionBar();
actionBar.setSubtitle("mytest");
actionBar.setTitle("vogella.com");